Add performance profiling to capture GetDutiesV2 operations taking over 2s

* fix IsBetterFinalityUpdate and add tests

fix finality update bugs

* Update lightclient.go

Co-authored-by: Radosław Kapka <rkapka@wp.pl>

* Update beacon-chain/core/light-client/lightclient.go

---------

Co-authored-by: Radosław Kapka <rkapka@wp.pl>

api/apiutil/BUILD.bazel

@@ -2,18 +2,28 @@ load("@prysm//tools/go:def.bzl", "go_library", "go_test")
 
 go_library(
     name = "go_default_library",
-    srcs = ["common.go"],
+    srcs = [
+        "common.go",
+        "header.go",
+    ],
     importpath = "github.com/OffchainLabs/prysm/v6/api/apiutil",
     visibility = ["//visibility:public"],
-    deps = ["//consensus-types/primitives:go_default_library"],
+    deps = [
+        "//consensus-types/primitives:go_default_library",
+        "@com_github_sirupsen_logrus//:go_default_library",
+    ],
 )
 
 go_test(
     name = "go_default_test",
-    srcs = ["common_test.go"],
+    srcs = [
+        "common_test.go",
+        "header_test.go",
+    ],
     embed = [":go_default_library"],
     deps = [
         "//consensus-types/primitives:go_default_library",
         "//testing/assert:go_default_library",
+        "//testing/require:go_default_library",
     ],
 )

api/apiutil/header.go

@@ -0,0 +1,122 @@
+package apiutil
+
+import (
+	"mime"
+	"sort"
+	"strconv"
+	"strings"
+
+	log "github.com/sirupsen/logrus"
+)
+
+type mediaRange struct {
+	mt   string  // canonicalised media‑type, e.g. "application/json"
+	q    float64 // quality factor (0‑1)
+	raw  string  // original string – useful for logging/debugging
+	spec int     // 2=exact, 1=type/*, 0=*/*
+}
+
+func parseMediaRange(field string) (mediaRange, bool) {
+	field = strings.TrimSpace(field)
+
+	mt, params, err := mime.ParseMediaType(field)
+	if err != nil {
+		log.WithError(err).Debug("Failed to parse header field")
+		return mediaRange{}, false
+	}
+
+	r := mediaRange{mt: mt, q: 1, spec: 2, raw: field}
+
+	if qs, ok := params["q"]; ok {
+		v, err := strconv.ParseFloat(qs, 64)
+		if err != nil || v < 0 || v > 1 {
+			log.WithField("q", qs).Debug("Invalid quality factor (0‑1)")
+			return mediaRange{}, false // skip invalid entry
+		}
+		r.q = v
+	}
+
+	switch {
+	case mt == "*/*":
+		r.spec = 0
+	case strings.HasSuffix(mt, "/*"):
+		r.spec = 1
+	}
+	return r, true
+}
+
+func hasExplicitQ(r mediaRange) bool {
+	return strings.Contains(strings.ToLower(r.raw), ";q=")
+}
+
+// ParseAccept returns media ranges sorted by q (desc) then specificity.
+func ParseAccept(header string) []mediaRange {
+	if header == "" {
+		return []mediaRange{{mt: "*/*", q: 1, spec: 0, raw: "*/*"}}
+	}
+
+	var out []mediaRange
+	for _, field := range strings.Split(header, ",") {
+		if r, ok := parseMediaRange(field); ok {
+			out = append(out, r)
+		}
+	}
+
+	sort.SliceStable(out, func(i, j int) bool {
+		ei, ej := hasExplicitQ(out[i]), hasExplicitQ(out[j])
+		if ei != ej {
+			return ei // explicit beats implicit
+		}
+		if out[i].q != out[j].q {
+			return out[i].q > out[j].q
+		}
+		return out[i].spec > out[j].spec
+	})
+	return out
+}
+
+// Matches reports whether content type is acceptable per the header.
+func Matches(header, ct string) bool {
+	for _, r := range ParseAccept(header) {
+		switch {
+		case r.q == 0:
+			continue
+		case r.mt == "*/*":
+			return true
+		case strings.HasSuffix(r.mt, "/*"):
+			if strings.HasPrefix(ct, r.mt[:len(r.mt)-1]) {
+				return true
+			}
+		case r.mt == ct:
+			return true
+		}
+	}
+	return false
+}
+
+// Negotiate selects the best server type according to the header.
+// Returns the chosen type and true, or "", false when nothing matches.
+func Negotiate(header string, serverTypes []string) (string, bool) {
+	for _, r := range ParseAccept(header) {
+		if r.q == 0 {
+			continue
+		}
+		for _, s := range serverTypes {
+			if Matches(r.mt, s) {
+				return s, true
+			}
+		}
+	}
+	return "", false
+}
+
+// PrimaryAcceptMatches only checks if the first accept matches
+func PrimaryAcceptMatches(header, produced string) bool {
+	for _, r := range ParseAccept(header) {
+		if r.q == 0 {
+			continue // explicitly unacceptable – skip
+		}
+		return Matches(r.mt, produced)
+	}
+	return false
+}

api/apiutil/header_test.go

@@ -0,0 +1,174 @@
+package apiutil
+
+import (
+	"testing"
+
+	"github.com/OffchainLabs/prysm/v6/testing/require"
+)
+
+func TestParseAccept(t *testing.T) {
+	type want struct {
+		mt   string
+		q    float64
+		spec int
+	}
+
+	cases := []struct {
+		name   string
+		header string
+		want   []want
+	}{
+		{
+			name:   "empty header becomes */*;q=1",
+			header: "",
+			want:   []want{{mt: "*/*", q: 1, spec: 0}},
+		},
+		{
+			name:   "quality ordering then specificity",
+			header: "application/json;q=0.2, */*;q=0.1, application/xml;q=0.5, text/*;q=0.5",
+			want: []want{
+				{mt: "application/xml", q: 0.5, spec: 2},
+				{mt: "text/*", q: 0.5, spec: 1},
+				{mt: "application/json", q: 0.2, spec: 2},
+				{mt: "*/*", q: 0.1, spec: 0},
+			},
+		},
+		{
+			name:   "invalid pieces are skipped",
+			header: "text/plain; q=boom, application/json",
+			want:   []want{{mt: "application/json", q: 1, spec: 2}},
+		},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			got := ParseAccept(tc.header)
+			gotProjected := make([]want, len(got))
+			for i, g := range got {
+				gotProjected[i] = want{mt: g.mt, q: g.q, spec: g.spec}
+			}
+			require.DeepEqual(t, gotProjected, tc.want)
+		})
+	}
+}
+
+func TestMatches(t *testing.T) {
+	cases := []struct {
+		name    string
+		accept  string
+		ct      string
+		matches bool
+	}{
+		{"exact match", "application/json", "application/json", true},
+		{"type wildcard", "application/*;q=0.8", "application/xml", true},
+		{"global wildcard", "*/*;q=0.1", "image/png", true},
+		{"explicitly unacceptable (q=0)", "text/*;q=0", "text/plain", false},
+		{"no match", "image/png", "application/json", false},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			got := Matches(tc.accept, tc.ct)
+			require.Equal(t, tc.matches, got)
+		})
+	}
+}
+
+func TestNegotiate(t *testing.T) {
+	cases := []struct {
+		name        string
+		accept      string
+		serverTypes []string
+		wantType    string
+		ok          bool
+	}{
+		{
+			name:        "highest quality wins",
+			accept:      "application/json;q=0.8,application/xml;q=0.9",
+			serverTypes: []string{"application/json", "application/xml"},
+			wantType:    "application/xml",
+			ok:          true,
+		},
+		{
+			name:        "wildcard matches first server type",
+			accept:      "*/*;q=0.5",
+			serverTypes: []string{"application/octet-stream", "application/json"},
+			wantType:    "application/octet-stream",
+			ok:          true,
+		},
+		{
+			name:        "no acceptable type",
+			accept:      "image/png",
+			serverTypes: []string{"application/json"},
+			wantType:    "",
+			ok:          false,
+		},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			got, ok := Negotiate(tc.accept, tc.serverTypes)
+			require.Equal(t, tc.ok, ok)
+			require.Equal(t, tc.wantType, got)
+		})
+	}
+}
+
+func TestPrimaryAcceptMatches(t *testing.T) {
+	tests := []struct {
+		name     string
+		accept   string
+		produced string
+		expect   bool
+	}{
+		{
+			name:     "prefers json",
+			accept:   "application/json;q=0.9,application/xml",
+			produced: "application/json",
+			expect:   true,
+		},
+		{
+			name:     "wildcard application beats other wildcard",
+			accept:   "application/*;q=0.2,*/*;q=0.1",
+			produced: "application/xml",
+			expect:   true,
+		},
+		{
+			name:     "json wins",
+			accept:   "application/xml;q=0.8,application/json;q=0.9",
+			produced: "application/json",
+			expect:   true,
+		},
+		{
+			name:     "json loses",
+			accept:   "application/xml;q=0.8,application/json;q=0.9,application/octet-stream;q=0.99",
+			produced: "application/json",
+			expect:   false,
+		},
+		{
+			name:     "json wins with non q option",
+			accept:   "application/xml;q=0.8,image/png,application/json;q=0.9",
+			produced: "application/json",
+			expect:   true,
+		},
+		{
+			name:     "json not primary",
+			accept:   "image/png,application/json",
+			produced: "application/json",
+			expect:   false,
+		},
+		{
+			name:     "absent header",
+			accept:   "",
+			produced: "text/plain",
+			expect:   true,
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			got := PrimaryAcceptMatches(tc.accept, tc.produced)
+			require.Equal(t, got, tc.expect)
+		})
+	}
+}

api/server/middleware/BUILD.bazel

@@ -10,6 +10,7 @@ go_library(
     visibility = ["//visibility:public"],
     deps = [
         "//api:go_default_library",
+        "//api/apiutil:go_default_library",
         "@com_github_rs_cors//:go_default_library",
         "@com_github_sirupsen_logrus//:go_default_library",
     ],

api/server/middleware/middleware.go

@@ -7,6 +7,7 @@ import (
 	"strings"
 
 	"github.com/OffchainLabs/prysm/v6/api"
+	"github.com/OffchainLabs/prysm/v6/api/apiutil"
 	"github.com/rs/cors"
 	log "github.com/sirupsen/logrus"
 )
@@ -74,42 +75,10 @@ func ContentTypeHandler(acceptedMediaTypes []string) Middleware {
 func AcceptHeaderHandler(serverAcceptedTypes []string) Middleware {
 	return func(next http.Handler) http.Handler {
 		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-			acceptHeader := r.Header.Get("Accept")
-			// header is optional and should skip if not provided
-			if acceptHeader == "" {
-				next.ServeHTTP(w, r)
+			if _, ok := apiutil.Negotiate(r.Header.Get("Accept"), serverAcceptedTypes); !ok {
+				http.Error(w, "Not Acceptable", http.StatusNotAcceptable)
 				return
 			}
-
-			accepted := false
-			acceptTypes := strings.Split(acceptHeader, ",")
-			// follows rules defined in https://datatracker.ietf.org/doc/html/rfc2616#section-14.1
-			for _, acceptType := range acceptTypes {
-				acceptType = strings.TrimSpace(acceptType)
-				if acceptType == "*/*" {
-					accepted = true
-					break
-				}
-				for _, serverAcceptedType := range serverAcceptedTypes {
-					if strings.HasPrefix(acceptType, serverAcceptedType) {
-						accepted = true
-						break
-					}
-					if acceptType != "/*" && strings.HasSuffix(acceptType, "/*") && strings.HasPrefix(serverAcceptedType, acceptType[:len(acceptType)-2]) {
-						accepted = true
-						break
-					}
-				}
-				if accepted {
-					break
-				}
-			}
-
-			if !accepted {
-				http.Error(w, fmt.Sprintf("Not Acceptable: %s", acceptHeader), http.StatusNotAcceptable)
-				return
-			}
-
 			next.ServeHTTP(w, r)
 		})
 	}

api/server/structs/BUILD.bazel

@@ -36,6 +36,7 @@ go_library(
         "//consensus-types/primitives:go_default_library",
         "//consensus-types/validator:go_default_library",
         "//container/slice:go_default_library",
+        "//crypto/bls:go_default_library",
         "//encoding/bytesutil:go_default_library",
         "//math:go_default_library",
         "//proto/engine/v1:go_default_library",

api/server/structs/conversions.go

@@ -10,6 +10,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/validator"
 	"github.com/OffchainLabs/prysm/v6/container/slice"
+	"github.com/OffchainLabs/prysm/v6/crypto/bls"
 	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
 	"github.com/OffchainLabs/prysm/v6/math"
 	enginev1 "github.com/OffchainLabs/prysm/v6/proto/engine/v1"
@@ -699,6 +700,11 @@ func (m *SyncCommitteeMessage) ToConsensus() (*eth.SyncCommitteeMessage, error)
 	if err != nil {
 		return nil, server.NewDecodeError(err, "Signature")
 	}
+	// Add validation to check if the signature is valid BLS format
+	_, err = bls.SignatureFromBytes(sig)
+	if err != nil {
+		return nil, server.NewDecodeError(err, "Signature")
+	}
 
 	return &eth.SyncCommitteeMessage{
 		Slot:           primitives.Slot(slot),

api/server/structs/endpoints_beacon.go

@@ -283,3 +283,10 @@ type GetPendingPartialWithdrawalsResponse struct {
 	Finalized           bool                        `json:"finalized"`
 	Data                []*PendingPartialWithdrawal `json:"data"`
 }
+
+type GetProposerLookaheadResponse struct {
+	Version             string   `json:"version"`
+	ExecutionOptimistic bool     `json:"execution_optimistic"`
+	Finalized           bool     `json:"finalized"`
+	Data                []string `json:"data"` // validator indexes
+}

api/server/structs/endpoints_node.go

@@ -27,6 +27,8 @@ type Identity struct {
 type Metadata struct {
 	SeqNumber string `json:"seq_number"`
 	Attnets   string `json:"attnets"`
+	Syncnets  string `json:"syncnets,omitempty"`
+	Cgc       string `json:"custody_group_count,omitempty"`
 }
 
 type GetPeerResponse struct {

beacon-chain/blockchain/execution_engine.go

@@ -174,6 +174,7 @@ func (s *Service) notifyForkchoiceUpdate(ctx context.Context, arg *fcuConfig) (*
 			"payloadID": fmt.Sprintf("%#x", bytesutil.Trunc(payloadID[:])),
 		}).Info("Forkchoice updated with payload attributes for proposal")
 		s.cfg.PayloadIDCache.Set(nextSlot, arg.headRoot, pId)
+		go s.firePayloadAttributesEvent(s.cfg.StateNotifier.StateFeed(), arg.headBlock, arg.headRoot, nextSlot)
 	} else if hasAttr && payloadID == nil && !features.Get().PrepareAllPayloads {
 		log.WithFields(logrus.Fields{
 			"blockHash": fmt.Sprintf("%#x", headPayload.BlockHash()),

beacon-chain/blockchain/forkchoice_update_execution.go

@@ -102,8 +102,6 @@ func (s *Service) forkchoiceUpdateWithExecution(ctx context.Context, args *fcuCo
 		log.WithError(err).Error("Could not save head")
 	}
 
-	go s.firePayloadAttributesEvent(s.cfg.StateNotifier.StateFeed(), args.headBlock, args.headRoot, s.CurrentSlot()+1)
-
 	// Only need to prune attestations from pool if the head has changed.
 	s.pruneAttsFromPool(s.ctx, args.headState, args.headBlock)
 	return nil

beacon-chain/blockchain/kzg/trusted_setup.go

@@ -11,7 +11,7 @@ import (
 )
 
 var (
-	// https://github.com/ethereum/consensus-specs/blob/dev/presets/mainnet/trusted_setups/trusted_setup_4096.json
+	// https://github.com/ethereum/consensus-specs/blob/master/presets/mainnet/trusted_setups/trusted_setup_4096.json
 	//go:embed trusted_setup_4096.json
 	embeddedTrustedSetup []byte // 1.2Mb
 	kzgContext           *GoKZG.Context

beacon-chain/blockchain/options.go

@@ -36,7 +36,7 @@ func WithMaxGoroutines(x int) Option {
 // WithLCStore for light client store access.
 func WithLCStore() Option {
 	return func(s *Service) error {
-		s.lcStore = lightclient.NewLightClientStore(s.cfg.BeaconDB)
+		s.lcStore = lightclient.NewLightClientStore(s.cfg.BeaconDB, s.cfg.P2P, s.cfg.StateNotifier.StateFeed())
 		return nil
 	}
 }

beacon-chain/blockchain/process_block.go

@@ -666,10 +666,9 @@ func (s *Service) areDataColumnsAvailable(
 	root [fieldparams.RootLength]byte,
 	block interfaces.ReadOnlyBeaconBlock,
 ) error {
-	// We are only required to check within MIN_EPOCHS_FOR_BLOB_SIDECARS_REQUESTS
+	// We are only required to check within MIN_EPOCHS_FOR_DATA_COLUMN_SIDECARS_REQUESTS.
 	blockSlot, currentSlot := block.Slot(), s.CurrentSlot()
 	blockEpoch, currentEpoch := slots.ToEpoch(blockSlot), slots.ToEpoch(currentSlot)
-
 	if !params.WithinDAPeriod(blockEpoch, currentEpoch) {
 		return nil
 	}

beacon-chain/blockchain/process_block_helpers.go

@@ -1,7 +1,6 @@
 package blockchain
 
 import (
-	"bytes"
 	"context"
 	"fmt"
 	"strings"
@@ -134,9 +133,6 @@ func (s *Service) processLightClientUpdates(cfg *postBlockProcessConfig) {
 	if err := s.processLightClientUpdate(cfg); err != nil {
 		log.WithError(err).Error("Failed to process light client update")
 	}
-	if err := s.processLightClientBootstrap(cfg); err != nil {
-		log.WithError(err).Error("Failed to process light client bootstrap")
-	}
 	if err := s.processLightClientOptimisticUpdate(cfg.ctx, cfg.roblock, cfg.postState); err != nil {
 		log.WithError(err).Error("Failed to process light client optimistic update")
 	}
@@ -174,15 +170,7 @@ func (s *Service) processLightClientUpdate(cfg *postBlockProcessConfig) error {
 		return errors.Wrapf(err, "could not get finalized block for root %#x", finalizedRoot)
 	}
 
-	update, err := lightclient.NewLightClientUpdateFromBeaconState(
-		cfg.ctx,
-		s.CurrentSlot(),
-		cfg.postState,
-		cfg.roblock,
-		attestedState,
-		attestedBlock,
-		finalizedBlock,
-	)
+	update, err := lightclient.NewLightClientUpdateFromBeaconState(cfg.ctx, cfg.postState, cfg.roblock, attestedState, attestedBlock, finalizedBlock)
 	if err != nil {
 		return errors.Wrapf(err, "could not create light client update")
 	}
@@ -192,20 +180,6 @@ func (s *Service) processLightClientUpdate(cfg *postBlockProcessConfig) error {
 	return s.lcStore.SaveLightClientUpdate(cfg.ctx, period, update)
 }
 
-// processLightClientBootstrap saves a light client bootstrap for this block
-// when feature flag is enabled.
-func (s *Service) processLightClientBootstrap(cfg *postBlockProcessConfig) error {
-	blockRoot := cfg.roblock.Root()
-	bootstrap, err := lightclient.NewLightClientBootstrapFromBeaconState(cfg.ctx, s.CurrentSlot(), cfg.postState, cfg.roblock)
-	if err != nil {
-		return errors.Wrapf(err, "could not create light client bootstrap")
-	}
-	if err := s.lcStore.SaveLightClientBootstrap(cfg.ctx, blockRoot, bootstrap); err != nil {
-		return errors.Wrapf(err, "could not save light client bootstrap")
-	}
-	return nil
-}
-
 func (s *Service) processLightClientFinalityUpdate(
 	ctx context.Context,
 	signed interfaces.ReadOnlySignedBeaconBlock,
@@ -223,8 +197,7 @@ func (s *Service) processLightClientFinalityUpdate(
 
 	finalizedCheckpoint := attestedState.FinalizedCheckpoint()
 
-	// Check if the finalized checkpoint has changed
-	if finalizedCheckpoint == nil || bytes.Equal(finalizedCheckpoint.GetRoot(), postState.FinalizedCheckpoint().Root) {
+	if finalizedCheckpoint == nil {
 		return nil
 	}
 
@@ -238,51 +211,18 @@ func (s *Service) processLightClientFinalityUpdate(
 		return errors.Wrapf(err, "could not get finalized block for root %#x", finalizedRoot)
 	}
 
-	newUpdate, err := lightclient.NewLightClientFinalityUpdateFromBeaconState(
-		ctx,
-		postState.Slot(),
-		postState,
-		signed,
-		attestedState,
-		attestedBlock,
-		finalizedBlock,
-	)
+	newUpdate, err := lightclient.NewLightClientFinalityUpdateFromBeaconState(ctx, postState, signed, attestedState, attestedBlock, finalizedBlock)
 
 	if err != nil {
 		return errors.Wrap(err, "could not create light client finality update")
 	}
 
-	lastUpdate := s.lcStore.LastFinalityUpdate()
-	if lastUpdate != nil {
-		// The finalized_header.beacon.lastUpdateSlot is greater than that of all previously forwarded finality_updates,
-		// or it matches the highest previously forwarded lastUpdateSlot and also has a sync_aggregate indicating supermajority (> 2/3)
-		// sync committee participation while the previously forwarded finality_update for that lastUpdateSlot did not indicate supermajority
-		newUpdateSlot := newUpdate.FinalizedHeader().Beacon().Slot
-		newHasSupermajority := lightclient.UpdateHasSupermajority(newUpdate.SyncAggregate())
-
-		lastUpdateSlot := lastUpdate.FinalizedHeader().Beacon().Slot
-		lastHasSupermajority := lightclient.UpdateHasSupermajority(lastUpdate.SyncAggregate())
-
-		if newUpdateSlot < lastUpdateSlot {
-			log.Debug("Skip saving light client finality newUpdate: Older than local newUpdate")
-			return nil
-		}
-		if newUpdateSlot == lastUpdateSlot && (lastHasSupermajority || !newHasSupermajority) {
-			log.Debug("Skip saving light client finality update: No supermajority advantage")
-			return nil
-		}
+	if !lightclient.IsBetterFinalityUpdate(newUpdate, s.lcStore.LastFinalityUpdate()) {
+		log.Debug("Skip saving light client finality update: current update is better")
+		return nil
 	}
-	log.Debug("Saving new light client finality update")
-	s.lcStore.SetLastFinalityUpdate(newUpdate)
 
-	s.cfg.StateNotifier.StateFeed().Send(&feed.Event{
-		Type: statefeed.LightClientFinalityUpdate,
-		Data: newUpdate,
-	})
-
-	if err = s.cfg.P2P.BroadcastLightClientFinalityUpdate(ctx, newUpdate); err != nil {
-		return errors.Wrap(err, "could not broadcast light client finality update")
-	}
+	s.lcStore.SetLastFinalityUpdate(newUpdate, true)
 
 	return nil
 }
@@ -299,14 +239,7 @@ func (s *Service) processLightClientOptimisticUpdate(ctx context.Context, signed
 		return errors.Wrapf(err, "could not get attested state for root %#x", attestedRoot)
 	}
 
-	newUpdate, err := lightclient.NewLightClientOptimisticUpdateFromBeaconState(
-		ctx,
-		postState.Slot(),
-		postState,
-		signed,
-		attestedState,
-		attestedBlock,
-	)
+	newUpdate, err := lightclient.NewLightClientOptimisticUpdateFromBeaconState(ctx, postState, signed, attestedState, attestedBlock)
 
 	if err != nil {
 		if strings.Contains(err.Error(), lightclient.ErrNotEnoughSyncCommitteeBits) {
@@ -316,26 +249,12 @@ func (s *Service) processLightClientOptimisticUpdate(ctx context.Context, signed
 		return errors.Wrap(err, "could not create light client optimistic update")
 	}
 
-	lastUpdate := s.lcStore.LastOptimisticUpdate()
-	if lastUpdate != nil {
-		// The attested_header.beacon.slot is greater than that of all previously forwarded optimistic updates
-		if newUpdate.AttestedHeader().Beacon().Slot <= lastUpdate.AttestedHeader().Beacon().Slot {
-			log.Debug("Skip saving light client optimistic update: Older than local update")
-			return nil
-		}
+	if !lightclient.IsBetterOptimisticUpdate(newUpdate, s.lcStore.LastOptimisticUpdate()) {
+		log.Debug("Skip saving light client optimistic update: current update is better")
+		return nil
 	}
 
-	log.Debug("Saving new light client optimistic update")
-	s.lcStore.SetLastOptimisticUpdate(newUpdate)
-
-	s.cfg.StateNotifier.StateFeed().Send(&feed.Event{
-		Type: statefeed.LightClientOptimisticUpdate,
-		Data: newUpdate,
-	})
-
-	if err = s.cfg.P2P.BroadcastLightClientOptimisticUpdate(ctx, newUpdate); err != nil {
-		return errors.Wrap(err, "could not broadcast light client optimistic update")
-	}
+	s.lcStore.SetLastOptimisticUpdate(newUpdate, true)
 
 	return nil
 }

beacon-chain/blockchain/process_block_test.go

@@ -2815,53 +2815,6 @@ func TestProcessLightClientUpdate(t *testing.T) {
 	}
 }
 
-func TestProcessLightClientBootstrap(t *testing.T) {
-	featCfg := &features.Flags{}
-	featCfg.EnableLightClient = true
-	reset := features.InitWithReset(featCfg)
-	defer reset()
-
-	s, tr := minimalTestService(t, WithLCStore())
-	ctx := tr.ctx
-
-	for testVersion := version.Altair; testVersion <= version.Electra; testVersion++ {
-		t.Run(version.String(testVersion), func(t *testing.T) {
-			l := util.NewTestLightClient(t, testVersion)
-
-			s.genesisTime = time.Unix(time.Now().Unix()-(int64(params.BeaconConfig().VersionToForkEpochMap()[testVersion])*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
-
-			currentBlockRoot, err := l.Block.Block().HashTreeRoot()
-			require.NoError(t, err)
-			roblock, err := consensusblocks.NewROBlockWithRoot(l.Block, currentBlockRoot)
-			require.NoError(t, err)
-
-			err = s.cfg.BeaconDB.SaveBlock(ctx, roblock)
-			require.NoError(t, err)
-			err = s.cfg.BeaconDB.SaveState(ctx, l.State, currentBlockRoot)
-			require.NoError(t, err)
-
-			cfg := &postBlockProcessConfig{
-				ctx:            ctx,
-				roblock:        roblock,
-				postState:      l.State,
-				isValidPayload: true,
-			}
-
-			require.NoError(t, s.processLightClientBootstrap(cfg))
-
-			// Check that the light client bootstrap is saved
-			b, err := s.lcStore.LightClientBootstrap(ctx, currentBlockRoot)
-			require.NoError(t, err)
-			require.NotNil(t, b)
-
-			stateRoot, err := l.State.HashTreeRoot(ctx)
-			require.NoError(t, err)
-			require.Equal(t, stateRoot, [32]byte(b.Header().Beacon().StateRoot))
-			require.Equal(t, b.Version(), testVersion)
-		})
-	}
-}
-
 type testIsAvailableParams struct {
 	options                 []Option
 	blobKzgCommitmentsCount uint64
@@ -3217,7 +3170,7 @@ func TestProcessLightClientOptimisticUpdate(t *testing.T) {
 
 			t.Run(version.String(testVersion)+"_"+tc.name, func(t *testing.T) {
 				s.genesisTime = time.Unix(time.Now().Unix()-(int64(forkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
-				s.lcStore = &lightClient.Store{}
+				s.lcStore = lightClient.NewLightClientStore(s.cfg.BeaconDB, s.cfg.P2P, s.cfg.StateNotifier.StateFeed())
 
 				var oldActualUpdate interfaces.LightClientOptimisticUpdate
 				var err error
@@ -3226,14 +3179,7 @@ func TestProcessLightClientOptimisticUpdate(t *testing.T) {
 					lOld, cfgOld := setupLightClientTestRequirements(ctx, t, s, testVersion, tc.oldOptions...)
 					require.NoError(t, s.processLightClientOptimisticUpdate(cfgOld.ctx, cfgOld.roblock, cfgOld.postState))
 
-					oldActualUpdate, err = lightClient.NewLightClientOptimisticUpdateFromBeaconState(
-						lOld.Ctx,
-						lOld.State.Slot(),
-						lOld.State,
-						lOld.Block,
-						lOld.AttestedState,
-						lOld.AttestedBlock,
-					)
+					oldActualUpdate, err = lightClient.NewLightClientOptimisticUpdateFromBeaconState(lOld.Ctx, lOld.State, lOld.Block, lOld.AttestedState, lOld.AttestedBlock)
 					require.NoError(t, err)
 
 					// check that the old update is saved
@@ -3247,14 +3193,7 @@ func TestProcessLightClientOptimisticUpdate(t *testing.T) {
 				lNew, cfgNew := setupLightClientTestRequirements(ctx, t, s, testVersion, tc.newOptions...)
 				require.NoError(t, s.processLightClientOptimisticUpdate(cfgNew.ctx, cfgNew.roblock, cfgNew.postState))
 
-				newActualUpdate, err := lightClient.NewLightClientOptimisticUpdateFromBeaconState(
-					lNew.Ctx,
-					lNew.State.Slot(),
-					lNew.State,
-					lNew.Block,
-					lNew.AttestedState,
-					lNew.AttestedBlock,
-				)
+				newActualUpdate, err := lightClient.NewLightClientOptimisticUpdateFromBeaconState(lNew.Ctx, lNew.State, lNew.Block, lNew.AttestedState, lNew.AttestedBlock)
 				require.NoError(t, err)
 
 				require.DeepNotEqual(t, newActualUpdate, oldActualUpdate, "new update should not be equal to old update")
@@ -3307,39 +3246,39 @@ func TestProcessLightClientFinalityUpdate(t *testing.T) {
 			expectReplace: true,
 		},
 		{
-			name:          "Old update is better - age - no supermajority",
+			name:          "Old update is better - finalized slot is higher",
 			oldOptions:    []util.LightClientOption{util.WithIncreasedFinalizedSlot(1)},
 			newOptions:    []util.LightClientOption{},
 			expectReplace: false,
 		},
 		{
-			name:          "Old update is better - age - both supermajority",
-			oldOptions:    []util.LightClientOption{util.WithIncreasedFinalizedSlot(1), util.WithSupermajority()},
-			newOptions:    []util.LightClientOption{util.WithSupermajority()},
-			expectReplace: false,
-		},
-		{
-			name:          "Old update is better - supermajority",
-			oldOptions:    []util.LightClientOption{util.WithSupermajority()},
+			name:          "Old update is better - attested slot is higher",
+			oldOptions:    []util.LightClientOption{util.WithIncreasedAttestedSlot(1)},
 			newOptions:    []util.LightClientOption{},
 			expectReplace: false,
 		},
 		{
-			name:          "New update is better - age - both supermajority",
-			oldOptions:    []util.LightClientOption{util.WithSupermajority()},
-			newOptions:    []util.LightClientOption{util.WithIncreasedFinalizedSlot(1), util.WithSupermajority()},
+			name:          "Old update is better - signature slot is higher",
+			oldOptions:    []util.LightClientOption{util.WithIncreasedSignatureSlot(1)},
+			newOptions:    []util.LightClientOption{},
+			expectReplace: false,
+		},
+		{
+			name:          "New update is better - finalized slot is higher",
+			oldOptions:    []util.LightClientOption{},
+			newOptions:    []util.LightClientOption{util.WithIncreasedAttestedSlot(1)},
 			expectReplace: true,
 		},
 		{
-			name:          "New update is better - age - no supermajority",
+			name:          "New update is better - attested slot is higher",
 			oldOptions:    []util.LightClientOption{},
-			newOptions:    []util.LightClientOption{util.WithIncreasedFinalizedSlot(1)},
+			newOptions:    []util.LightClientOption{util.WithIncreasedAttestedSlot(1)},
 			expectReplace: true,
 		},
 		{
-			name:          "New update is better - supermajority",
+			name:          "New update is better - signature slot is higher",
 			oldOptions:    []util.LightClientOption{},
-			newOptions:    []util.LightClientOption{util.WithSupermajority()},
+			newOptions:    []util.LightClientOption{util.WithIncreasedSignatureSlot(1)},
 			expectReplace: true,
 		},
 	}
@@ -3371,7 +3310,7 @@ func TestProcessLightClientFinalityUpdate(t *testing.T) {
 
 			t.Run(version.String(testVersion)+"_"+tc.name, func(t *testing.T) {
 				s.genesisTime = time.Unix(time.Now().Unix()-(int64(forkEpoch)*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot)), 0)
-				s.lcStore = &lightClient.Store{}
+				s.lcStore = lightClient.NewLightClientStore(s.cfg.BeaconDB, s.cfg.P2P, s.cfg.StateNotifier.StateFeed())
 
 				var actualOldUpdate, actualNewUpdate interfaces.LightClientFinalityUpdate
 				var err error
@@ -3382,15 +3321,7 @@ func TestProcessLightClientFinalityUpdate(t *testing.T) {
 					require.NoError(t, s.processLightClientFinalityUpdate(cfgOld.ctx, cfgOld.roblock, cfgOld.postState))
 
 					// check that the old update is saved
-					actualOldUpdate, err = lightClient.NewLightClientFinalityUpdateFromBeaconState(
-						ctx,
-						cfgOld.postState.Slot(),
-						cfgOld.postState,
-						cfgOld.roblock,
-						lOld.AttestedState,
-						lOld.AttestedBlock,
-						lOld.FinalizedBlock,
-					)
+					actualOldUpdate, err = lightClient.NewLightClientFinalityUpdateFromBeaconState(ctx, cfgOld.postState, cfgOld.roblock, lOld.AttestedState, lOld.AttestedBlock, lOld.FinalizedBlock)
 					require.NoError(t, err)
 					oldUpdate := s.lcStore.LastFinalityUpdate()
 					require.DeepEqual(t, actualOldUpdate, oldUpdate)
@@ -3401,15 +3332,7 @@ func TestProcessLightClientFinalityUpdate(t *testing.T) {
 				require.NoError(t, s.processLightClientFinalityUpdate(cfgNew.ctx, cfgNew.roblock, cfgNew.postState))
 
 				// check that the actual old update and the actual new update are different
-				actualNewUpdate, err = lightClient.NewLightClientFinalityUpdateFromBeaconState(
-					ctx,
-					cfgNew.postState.Slot(),
-					cfgNew.postState,
-					cfgNew.roblock,
-					lNew.AttestedState,
-					lNew.AttestedBlock,
-					lNew.FinalizedBlock,
-				)
+				actualNewUpdate, err = lightClient.NewLightClientFinalityUpdateFromBeaconState(ctx, cfgNew.postState, cfgNew.roblock, lNew.AttestedState, lNew.AttestedBlock, lNew.FinalizedBlock)
 				require.NoError(t, err)
 				require.DeepNotEqual(t, actualOldUpdate, actualNewUpdate)
 

beacon-chain/blockchain/receive_attestation.go

@@ -177,7 +177,7 @@ func (s *Service) processAttestations(ctx context.Context, disparity time.Durati
 	for _, a := range atts {
 		// Based on the spec, don't process the attestation until the subsequent slot.
 		// This delays consideration in the fork choice until their slot is in the past.
-		// https://github.com/ethereum/consensus-specs/blob/dev/specs/phase0/fork-choice.md#validate_on_attestation
+		// https://github.com/ethereum/consensus-specs/blob/master/specs/phase0/fork-choice.md#validate_on_attestation
 		nextSlot := a.GetData().Slot + 1
 		if err := slots.VerifyTime(s.genesisTime, nextSlot, disparity); err != nil {
 			continue

beacon-chain/blockchain/receive_block.go

@@ -300,15 +300,30 @@ func (s *Service) reportPostBlockProcessing(
 
 func (s *Service) executePostFinalizationTasks(ctx context.Context, finalizedState state.BeaconState) {
 	finalized := s.cfg.ForkChoiceStore.FinalizedCheckpoint()
+
+	// Send finalization event
 	go func() {
 		s.sendNewFinalizedEvent(ctx, finalizedState)
 	}()
 
+	// Insert finalized deposits into finalized deposit trie
 	depCtx, cancel := context.WithTimeout(context.Background(), depositDeadline)
 	go func() {
 		s.insertFinalizedDepositsAndPrune(depCtx, finalized.Root)
 		cancel()
 	}()
+
+	if features.Get().EnableLightClient {
+		// Save a light client bootstrap for the finalized checkpoint
+		go func() {
+			err := s.lcStore.SaveLightClientBootstrap(s.ctx, finalized.Root)
+			if err != nil {
+				log.WithError(err).Error("Could not save light client bootstrap by block root")
+			} else {
+				log.Debugf("Saved light client bootstrap for finalized root %#x", finalized.Root)
+			}
+		}()
+	}
 }
 
 // ReceiveBlockBatch processes the whole block batch at once, assuming the block batch is linear ,transitioning

beacon-chain/blockchain/receive_block_test.go

@@ -9,7 +9,9 @@ import (
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/cache"
 	statefeed "github.com/OffchainLabs/prysm/v6/beacon-chain/core/feed/state"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/helpers"
+	lightClient "github.com/OffchainLabs/prysm/v6/beacon-chain/core/light-client"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/das"
+	forkchoicetypes "github.com/OffchainLabs/prysm/v6/beacon-chain/forkchoice/types"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/operations/voluntaryexits"
 	"github.com/OffchainLabs/prysm/v6/config/features"
 	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
@@ -19,6 +21,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
 	ethpbv1 "github.com/OffchainLabs/prysm/v6/proto/eth/v1"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
+	"github.com/OffchainLabs/prysm/v6/runtime/version"
 	"github.com/OffchainLabs/prysm/v6/testing/assert"
 	"github.com/OffchainLabs/prysm/v6/testing/require"
 	"github.com/OffchainLabs/prysm/v6/testing/util"
@@ -564,3 +567,48 @@ func Test_executePostFinalizationTasks(t *testing.T) {
 	})
 
 }
+
+func TestProcessLightClientBootstrap(t *testing.T) {
+	featCfg := &features.Flags{}
+	featCfg.EnableLightClient = true
+	reset := features.InitWithReset(featCfg)
+	defer reset()
+
+	s, tr := minimalTestService(t, WithLCStore())
+	ctx := tr.ctx
+
+	for testVersion := version.Altair; testVersion <= version.Electra; testVersion++ {
+		t.Run(version.String(testVersion), func(t *testing.T) {
+			l := util.NewTestLightClient(t, testVersion)
+
+			require.NoError(t, s.cfg.BeaconDB.SaveBlock(ctx, l.FinalizedBlock))
+			finalizedBlockRoot, err := l.FinalizedBlock.Block().HashTreeRoot()
+			require.NoError(t, err)
+			require.NoError(t, s.cfg.BeaconDB.SaveState(ctx, l.FinalizedState, finalizedBlockRoot))
+
+			cp := l.AttestedState.FinalizedCheckpoint()
+			require.DeepSSZEqual(t, finalizedBlockRoot, [32]byte(cp.Root))
+
+			require.NoError(t, s.cfg.ForkChoiceStore.UpdateFinalizedCheckpoint(&forkchoicetypes.Checkpoint{Epoch: cp.Epoch, Root: [32]byte(cp.Root)}))
+
+			sss, err := s.cfg.BeaconDB.State(ctx, finalizedBlockRoot)
+			require.NoError(t, err)
+			require.NotNil(t, sss)
+
+			s.executePostFinalizationTasks(s.ctx, l.FinalizedState)
+
+			// wait for the goroutine to finish processing
+			time.Sleep(1 * time.Second)
+
+			// Check that the light client bootstrap is saved
+			b, err := s.lcStore.LightClientBootstrap(ctx, [32]byte(cp.Root))
+			require.NoError(t, err)
+			require.NotNil(t, b)
+
+			btst, err := lightClient.NewLightClientBootstrapFromBeaconState(ctx, l.FinalizedState.Slot(), l.FinalizedState, l.FinalizedBlock)
+			require.NoError(t, err)
+			require.DeepEqual(t, btst, b)
+			require.Equal(t, b.Version(), testVersion)
+		})
+	}
+}

beacon-chain/blockchain/receive_data_column.go

@@ -15,7 +15,6 @@ func (s *Service) ReceiveDataColumns(dataColumnSidecars []blocks.VerifiedRODataC
 }
 
 // ReceiveDataColumn receives a single data column.
-// (It is only a wrapper around ReceiveDataColumns.)
 func (s *Service) ReceiveDataColumn(dataColumnSidecar blocks.VerifiedRODataColumn) error {
 	if err := s.dataColumnStorage.Save([]blocks.VerifiedRODataColumn{dataColumnSidecar}); err != nil {
 		return errors.Wrap(err, "save data column sidecars")

beacon-chain/blockchain/setup_test.go

@@ -87,7 +87,7 @@ func (mb *mockBroadcaster) BroadcastLightClientFinalityUpdate(_ context.Context,
 	return nil
 }
 
-func (mb *mockBroadcaster) BroadcastDataColumn(_ [fieldparams.RootLength]byte, _ uint64, _ *ethpb.DataColumnSidecar, _ ...chan<- bool) error {
+func (mb *mockBroadcaster) BroadcastDataColumn(_ [fieldparams.RootLength]byte, _ uint64, _ *ethpb.DataColumnSidecar) error {
 	mb.broadcastCalled = true
 	return nil
 }

beacon-chain/builder/service.go

@@ -68,7 +68,7 @@ func NewService(ctx context.Context, opts ...Option) (*Service, error) {
 			log.WithError(err).Error("Failed to check builder status")
 		} else {
 			log.WithField("endpoint", s.c.NodeURL()).Info("Builder has been configured")
-			log.Warn("Outsourcing block construction to external builders adds non-trivial delay to block propagation time.  " +
+			log.Warn("Outsourcing block construction to external builders adds non-trivial delay to block propagation time. " +
 				"Builder-constructed blocks or fallback blocks may get orphaned. Use at your own risk!")
 		}
 	}

beacon-chain/core/helpers/weak_subjectivity.go

@@ -206,9 +206,9 @@ func ParseWeakSubjectivityInputString(wsCheckpointString string) (*v1alpha1.Chec
 // MinEpochsForBlockRequests computes the number of epochs of block history that we need to maintain,
 // relative to the current epoch, per the p2p specs. This is used to compute the slot where backfill is complete.
 // value defined:
-// https://github.com/ethereum/consensus-specs/blob/dev/specs/phase0/p2p-interface.md#configuration
+// https://github.com/ethereum/consensus-specs/blob/master/specs/phase0/p2p-interface.md#configuration
 // MIN_VALIDATOR_WITHDRAWABILITY_DELAY + CHURN_LIMIT_QUOTIENT // 2 (= 33024, ~5 months)
-// detailed rationale: https://github.com/ethereum/consensus-specs/blob/dev/specs/phase0/p2p-interface.md#why-are-blocksbyrange-requests-only-required-to-be-served-for-the-latest-min_epochs_for_block_requests-epochs
+// detailed rationale: https://github.com/ethereum/consensus-specs/blob/master/specs/phase0/p2p-interface.md#why-are-blocksbyrange-requests-only-required-to-be-served-for-the-latest-min_epochs_for_block_requests-epochs
 func MinEpochsForBlockRequests() primitives.Epoch {
 	return params.BeaconConfig().MinValidatorWithdrawabilityDelay +
 		primitives.Epoch(params.BeaconConfig().ChurnLimitQuotient/2)

beacon-chain/core/helpers/weak_subjectivity_test.go

@@ -292,7 +292,7 @@ func TestMinEpochsForBlockRequests(t *testing.T) {
 	params.SetActiveTestCleanup(t, params.MainnetConfig())
 	var expected primitives.Epoch = 33024
 	// expected value of 33024 via spec commentary:
-	// https://github.com/ethereum/consensus-specs/blob/dev/specs/phase0/p2p-interface.md#why-are-blocksbyrange-requests-only-required-to-be-served-for-the-latest-min_epochs_for_block_requests-epochs
+	// https://github.com/ethereum/consensus-specs/blob/master/specs/phase0/p2p-interface.md#why-are-blocksbyrange-requests-only-required-to-be-served-for-the-latest-min_epochs_for_block_requests-epochs
 	//	MIN_EPOCHS_FOR_BLOCK_REQUESTS is calculated using the arithmetic from compute_weak_subjectivity_period found in the weak subjectivity guide. Specifically to find this max epoch range, we use the worst case event of a very large validator size (>= MIN_PER_EPOCH_CHURN_LIMIT * CHURN_LIMIT_QUOTIENT).
 	//
 	//	MIN_EPOCHS_FOR_BLOCK_REQUESTS = (

beacon-chain/core/light-client/BUILD.bazel

@@ -10,8 +10,12 @@ go_library(
     importpath = "github.com/OffchainLabs/prysm/v6/beacon-chain/core/light-client",
     visibility = ["//visibility:public"],
     deps = [
+        "//async/event:go_default_library",
+        "//beacon-chain/core/feed:go_default_library",
+        "//beacon-chain/core/feed/state:go_default_library",
         "//beacon-chain/db/iface:go_default_library",
         "//beacon-chain/execution:go_default_library",
+        "//beacon-chain/p2p:go_default_library",
         "//beacon-chain/state:go_default_library",
         "//config/fieldparams:go_default_library",
         "//config/params:go_default_library",
@@ -39,6 +43,9 @@ go_test(
     ],
     deps = [
         ":go_default_library",
+        "//async/event:go_default_library",
+        "//beacon-chain/db/testing:go_default_library",
+        "//beacon-chain/p2p/testing:go_default_library",
         "//config/fieldparams:go_default_library",
         "//config/params:go_default_library",
         "//consensus-types:go_default_library",

beacon-chain/core/light-client/lightclient.go

@@ -26,14 +26,12 @@ const ErrNotEnoughSyncCommitteeBits = "sync committee bits count is less than re
 
 func NewLightClientFinalityUpdateFromBeaconState(
 	ctx context.Context,
-	currentSlot primitives.Slot,
 	state state.BeaconState,
 	block interfaces.ReadOnlySignedBeaconBlock,
 	attestedState state.BeaconState,
 	attestedBlock interfaces.ReadOnlySignedBeaconBlock,
-	finalizedBlock interfaces.ReadOnlySignedBeaconBlock,
-) (interfaces.LightClientFinalityUpdate, error) {
-	update, err := NewLightClientUpdateFromBeaconState(ctx, currentSlot, state, block, attestedState, attestedBlock, finalizedBlock)
+	finalizedBlock interfaces.ReadOnlySignedBeaconBlock) (interfaces.LightClientFinalityUpdate, error) {
+	update, err := NewLightClientUpdateFromBeaconState(ctx, state, block, attestedState, attestedBlock, finalizedBlock)
 	if err != nil {
 		return nil, err
 	}
@@ -43,13 +41,11 @@ func NewLightClientFinalityUpdateFromBeaconState(
 
 func NewLightClientOptimisticUpdateFromBeaconState(
 	ctx context.Context,
-	currentSlot primitives.Slot,
 	state state.BeaconState,
 	block interfaces.ReadOnlySignedBeaconBlock,
 	attestedState state.BeaconState,
-	attestedBlock interfaces.ReadOnlySignedBeaconBlock,
-) (interfaces.LightClientOptimisticUpdate, error) {
-	update, err := NewLightClientUpdateFromBeaconState(ctx, currentSlot, state, block, attestedState, attestedBlock, nil)
+	attestedBlock interfaces.ReadOnlySignedBeaconBlock) (interfaces.LightClientOptimisticUpdate, error) {
+	update, err := NewLightClientUpdateFromBeaconState(ctx, state, block, attestedState, attestedBlock, nil)
 	if err != nil {
 		return nil, err
 	}
@@ -66,7 +62,6 @@ func NewLightClientOptimisticUpdateFromBeaconState(
 //     if locally available (may be unavailable, e.g., when using checkpoint sync, or if it was pruned locally)
 func NewLightClientUpdateFromBeaconState(
 	ctx context.Context,
-	currentSlot primitives.Slot,
 	state state.BeaconState,
 	block interfaces.ReadOnlySignedBeaconBlock,
 	attestedState state.BeaconState,
@@ -521,8 +516,7 @@ func ComputeWithdrawalsRoot(payload interfaces.ExecutionData) ([]byte, error) {
 func BlockToLightClientHeader(
 	ctx context.Context,
 	attestedBlockVersion int, // this is the version that the light client header should be in, based on the attested block.
-	block interfaces.ReadOnlySignedBeaconBlock, // this block is either the attested block, or the finalized block.
-	// in case of the latter, we might need to upgrade it to the attested block's version.
+	block interfaces.ReadOnlySignedBeaconBlock, // this block is either the attested block, or the finalized block. in case of the latter, we might need to upgrade it to the attested block's version.
 ) (interfaces.LightClientHeader, error) {
 	if block.Version() > attestedBlockVersion {
 		return nil, errors.Errorf("block version %s is greater than attested block version %s", version.String(block.Version()), version.String(attestedBlockVersion))
@@ -755,3 +749,64 @@ func UpdateHasSupermajority(syncAggregate *pb.SyncAggregate) bool {
 	numActiveParticipants := syncAggregate.SyncCommitteeBits.Count()
 	return numActiveParticipants*3 >= maxActiveParticipants*2
 }
+
+// IsFinalityUpdateValidForBroadcast checks if a finality update needs to be broadcasted.
+// It is also used to check if an incoming gossiped finality update is valid for forwarding and saving.
+func IsFinalityUpdateValidForBroadcast(newUpdate, oldUpdate interfaces.LightClientFinalityUpdate) bool {
+	if oldUpdate == nil {
+		return true
+	}
+	// The finalized_header.beacon.slot is greater than that of all previously forwarded finality_updates,
+	// or it matches the highest previously forwarded slot and also has a sync_aggregate indicating supermajority (> 2/3)
+	// sync committee participation while the previously forwarded finality_update for that slot did not indicate supermajority
+	newUpdateSlot := newUpdate.FinalizedHeader().Beacon().Slot
+	newHasSupermajority := UpdateHasSupermajority(newUpdate.SyncAggregate())
+
+	lastUpdateSlot := oldUpdate.FinalizedHeader().Beacon().Slot
+	lastHasSupermajority := UpdateHasSupermajority(oldUpdate.SyncAggregate())
+
+	if newUpdateSlot < lastUpdateSlot {
+		return false
+	}
+	if newUpdateSlot == lastUpdateSlot && (lastHasSupermajority || !newHasSupermajority) {
+		return false
+	}
+	return true
+}
+
+// IsBetterFinalityUpdate checks if the new finality update is better than the old one for saving.
+// This does not concern broadcasting, but rather the decision of whether to save the new update.
+// For broadcasting checks, use IsFinalityUpdateValidForBroadcast.
+func IsBetterFinalityUpdate(newUpdate, oldUpdate interfaces.LightClientFinalityUpdate) bool {
+	if oldUpdate == nil {
+		return true
+	}
+
+	// Full nodes SHOULD provide the LightClientFinalityUpdate with the highest attested_header.beacon.slot (if multiple, highest signature_slot)
+	newFinalizedSlot := newUpdate.FinalizedHeader().Beacon().Slot
+	newAttestedSlot := newUpdate.AttestedHeader().Beacon().Slot
+
+	oldFinalizedSlot := oldUpdate.FinalizedHeader().Beacon().Slot
+	oldAttestedSlot := oldUpdate.AttestedHeader().Beacon().Slot
+
+	if newFinalizedSlot < oldFinalizedSlot {
+		return false
+	}
+	if newFinalizedSlot == oldFinalizedSlot {
+		if newAttestedSlot < oldAttestedSlot {
+			return false
+		}
+		if newAttestedSlot == oldAttestedSlot && newUpdate.SignatureSlot() <= oldUpdate.SignatureSlot() {
+			return false
+		}
+	}
+	return true
+}
+
+func IsBetterOptimisticUpdate(newUpdate, oldUpdate interfaces.LightClientOptimisticUpdate) bool {
+	if oldUpdate == nil {
+		return true
+	}
+	// The attested_header.beacon.slot is greater than that of all previously forwarded optimistic updates
+	return newUpdate.AttestedHeader().Beacon().Slot > oldUpdate.AttestedHeader().Beacon().Slot
+}

beacon-chain/core/light-client/lightclient_test.go

@@ -34,7 +34,7 @@ func TestLightClient_NewLightClientOptimisticUpdateFromBeaconState(t *testing.T)
 	t.Run("Altair", func(t *testing.T) {
 		l := util.NewTestLightClient(t, version.Altair)
 
-		update, err := lightClient.NewLightClientOptimisticUpdateFromBeaconState(l.Ctx, l.State.Slot(), l.State, l.Block, l.AttestedState, l.AttestedBlock)
+		update, err := lightClient.NewLightClientOptimisticUpdateFromBeaconState(l.Ctx, l.State, l.Block, l.AttestedState, l.AttestedBlock)
 		require.NoError(t, err)
 		require.NotNil(t, update, "update is nil")
 		require.Equal(t, l.Block.Block().Slot(), update.SignatureSlot(), "Signature slot is not equal")
@@ -46,7 +46,7 @@ func TestLightClient_NewLightClientOptimisticUpdateFromBeaconState(t *testing.T)
 	t.Run("Capella", func(t *testing.T) {
 		l := util.NewTestLightClient(t, version.Capella)
 
-		update, err := lightClient.NewLightClientOptimisticUpdateFromBeaconState(l.Ctx, l.State.Slot(), l.State, l.Block, l.AttestedState, l.AttestedBlock)
+		update, err := lightClient.NewLightClientOptimisticUpdateFromBeaconState(l.Ctx, l.State, l.Block, l.AttestedState, l.AttestedBlock)
 		require.NoError(t, err)
 		require.NotNil(t, update, "update is nil")
 
@@ -59,7 +59,7 @@ func TestLightClient_NewLightClientOptimisticUpdateFromBeaconState(t *testing.T)
 	t.Run("Deneb", func(t *testing.T) {
 		l := util.NewTestLightClient(t, version.Deneb)
 
-		update, err := lightClient.NewLightClientOptimisticUpdateFromBeaconState(l.Ctx, l.State.Slot(), l.State, l.Block, l.AttestedState, l.AttestedBlock)
+		update, err := lightClient.NewLightClientOptimisticUpdateFromBeaconState(l.Ctx, l.State, l.Block, l.AttestedState, l.AttestedBlock)
 		require.NoError(t, err)
 		require.NotNil(t, update, "update is nil")
 
@@ -72,7 +72,7 @@ func TestLightClient_NewLightClientOptimisticUpdateFromBeaconState(t *testing.T)
 	t.Run("Electra", func(t *testing.T) {
 		l := util.NewTestLightClient(t, version.Electra)
 
-		update, err := lightClient.NewLightClientOptimisticUpdateFromBeaconState(l.Ctx, l.State.Slot(), l.State, l.Block, l.AttestedState, l.AttestedBlock)
+		update, err := lightClient.NewLightClientOptimisticUpdateFromBeaconState(l.Ctx, l.State, l.Block, l.AttestedState, l.AttestedBlock)
 		require.NoError(t, err)
 		require.NotNil(t, update, "update is nil")
 
@@ -97,7 +97,7 @@ func TestLightClient_NewLightClientFinalityUpdateFromBeaconState(t *testing.T) {
 		l := util.NewTestLightClient(t, version.Altair)
 
 		t.Run("FinalizedBlock Not Nil", func(t *testing.T) {
-			update, err := lightClient.NewLightClientFinalityUpdateFromBeaconState(l.Ctx, l.State.Slot(), l.State, l.Block, l.AttestedState, l.AttestedBlock, l.FinalizedBlock)
+			update, err := lightClient.NewLightClientFinalityUpdateFromBeaconState(l.Ctx, l.State, l.Block, l.AttestedState, l.AttestedBlock, l.FinalizedBlock)
 			require.NoError(t, err)
 			require.NotNil(t, update, "update is nil")
 
@@ -132,7 +132,7 @@ func TestLightClient_NewLightClientFinalityUpdateFromBeaconState(t *testing.T) {
 
 		t.Run("FinalizedBlock Not Nil", func(t *testing.T) {
 			l := util.NewTestLightClient(t, version.Capella)
-			update, err := lightClient.NewLightClientFinalityUpdateFromBeaconState(l.Ctx, l.State.Slot(), l.State, l.Block, l.AttestedState, l.AttestedBlock, l.FinalizedBlock)
+			update, err := lightClient.NewLightClientFinalityUpdateFromBeaconState(l.Ctx, l.State, l.Block, l.AttestedState, l.AttestedBlock, l.FinalizedBlock)
 			require.NoError(t, err)
 			require.NotNil(t, update, "update is nil")
 
@@ -206,7 +206,7 @@ func TestLightClient_NewLightClientFinalityUpdateFromBeaconState(t *testing.T) {
 
 		t.Run("FinalizedBlock In Previous Fork", func(t *testing.T) {
 			l := util.NewTestLightClient(t, version.Capella, util.WithFinalizedCheckpointInPrevFork())
-			update, err := lightClient.NewLightClientFinalityUpdateFromBeaconState(l.Ctx, l.State.Slot(), l.State, l.Block, l.AttestedState, l.AttestedBlock, l.FinalizedBlock)
+			update, err := lightClient.NewLightClientFinalityUpdateFromBeaconState(l.Ctx, l.State, l.Block, l.AttestedState, l.AttestedBlock, l.FinalizedBlock)
 			require.NoError(t, err)
 			require.NotNil(t, update, "update is nil")
 
@@ -240,7 +240,7 @@ func TestLightClient_NewLightClientFinalityUpdateFromBeaconState(t *testing.T) {
 		t.Run("FinalizedBlock Not Nil", func(t *testing.T) {
 			l := util.NewTestLightClient(t, version.Deneb)
 
-			update, err := lightClient.NewLightClientFinalityUpdateFromBeaconState(l.Ctx, l.State.Slot(), l.State, l.Block, l.AttestedState, l.AttestedBlock, l.FinalizedBlock)
+			update, err := lightClient.NewLightClientFinalityUpdateFromBeaconState(l.Ctx, l.State, l.Block, l.AttestedState, l.AttestedBlock, l.FinalizedBlock)
 			require.NoError(t, err)
 			require.NotNil(t, update, "update is nil")
 
@@ -315,7 +315,7 @@ func TestLightClient_NewLightClientFinalityUpdateFromBeaconState(t *testing.T) {
 		t.Run("FinalizedBlock In Previous Fork", func(t *testing.T) {
 			l := util.NewTestLightClient(t, version.Deneb, util.WithFinalizedCheckpointInPrevFork())
 
-			update, err := lightClient.NewLightClientFinalityUpdateFromBeaconState(l.Ctx, l.State.Slot(), l.State, l.Block, l.AttestedState, l.AttestedBlock, l.FinalizedBlock)
+			update, err := lightClient.NewLightClientFinalityUpdateFromBeaconState(l.Ctx, l.State, l.Block, l.AttestedState, l.AttestedBlock, l.FinalizedBlock)
 			require.NoError(t, err)
 			require.NotNil(t, update, "update is nil")
 
@@ -392,7 +392,7 @@ func TestLightClient_NewLightClientFinalityUpdateFromBeaconState(t *testing.T) {
 		t.Run("FinalizedBlock Not Nil", func(t *testing.T) {
 			l := util.NewTestLightClient(t, version.Electra)
 
-			update, err := lightClient.NewLightClientFinalityUpdateFromBeaconState(l.Ctx, l.State.Slot(), l.State, l.Block, l.AttestedState, l.AttestedBlock, l.FinalizedBlock)
+			update, err := lightClient.NewLightClientFinalityUpdateFromBeaconState(l.Ctx, l.State, l.Block, l.AttestedState, l.AttestedBlock, l.FinalizedBlock)
 			require.NoError(t, err)
 			require.NotNil(t, update, "update is nil")
 
@@ -467,7 +467,7 @@ func TestLightClient_NewLightClientFinalityUpdateFromBeaconState(t *testing.T) {
 		t.Run("FinalizedBlock In Previous Fork", func(t *testing.T) {
 			l := util.NewTestLightClient(t, version.Electra, util.WithFinalizedCheckpointInPrevFork())
 
-			update, err := lightClient.NewLightClientFinalityUpdateFromBeaconState(l.Ctx, l.State.Slot(), l.State, l.Block, l.AttestedState, l.AttestedBlock, l.FinalizedBlock)
+			update, err := lightClient.NewLightClientFinalityUpdateFromBeaconState(l.Ctx, l.State, l.Block, l.AttestedState, l.AttestedBlock, l.FinalizedBlock)
 			require.NoError(t, err)
 			require.NotNil(t, update, "update is nil")
 

beacon-chain/core/light-client/store.go

@@ -4,7 +4,11 @@ import (
 	"context"
 	"sync"
 
+	"github.com/OffchainLabs/prysm/v6/async/event"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/feed"
+	statefeed "github.com/OffchainLabs/prysm/v6/beacon-chain/core/feed/state"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/db/iface"
+	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
 	"github.com/pkg/errors"
 	log "github.com/sirupsen/logrus"
@@ -16,13 +20,17 @@ type Store struct {
 	mu sync.RWMutex
 
 	beaconDB             iface.HeadAccessDatabase
-	lastFinalityUpdate   interfaces.LightClientFinalityUpdate
-	lastOptimisticUpdate interfaces.LightClientOptimisticUpdate
+	lastFinalityUpdate   interfaces.LightClientFinalityUpdate   // tracks the best finality update seen so far
+	lastOptimisticUpdate interfaces.LightClientOptimisticUpdate // tracks the best optimistic update seen so far
+	p2p                  p2p.Accessor
+	stateFeed            event.SubscriberSender
 }
 
-func NewLightClientStore(db iface.HeadAccessDatabase) *Store {
+func NewLightClientStore(db iface.HeadAccessDatabase, p p2p.Accessor, e event.SubscriberSender) *Store {
 	return &Store{
-		beaconDB: db,
+		beaconDB:  db,
+		p2p:       p,
+		stateFeed: e,
 	}
 }
 
@@ -42,10 +50,31 @@ func (s *Store) LightClientBootstrap(ctx context.Context, blockRoot [32]byte) (i
 	return bootstrap, nil
 }
 
-func (s *Store) SaveLightClientBootstrap(ctx context.Context, blockRoot [32]byte, bootstrap interfaces.LightClientBootstrap) error {
+func (s *Store) SaveLightClientBootstrap(ctx context.Context, blockRoot [32]byte) error {
 	s.mu.Lock()
 	defer s.mu.Unlock()
 
+	blk, err := s.beaconDB.Block(ctx, blockRoot)
+	if err != nil {
+		return errors.Wrapf(err, "failed to fetch block for root %x", blockRoot)
+	}
+	if blk == nil {
+		return errors.Errorf("failed to fetch block for root %x", blockRoot)
+	}
+
+	state, err := s.beaconDB.State(ctx, blockRoot)
+	if err != nil {
+		return errors.Wrapf(err, "failed to fetch state for block root %x", blockRoot)
+	}
+	if state == nil {
+		return errors.Errorf("failed to fetch state for block root %x", blockRoot)
+	}
+
+	bootstrap, err := NewLightClientBootstrapFromBeaconState(ctx, state.Slot(), state, blk)
+	if err != nil {
+		return errors.Wrapf(err, "failed to create light client bootstrap for block root %x", blockRoot)
+	}
+
 	// Save the light client bootstrap to the database
 	if err := s.beaconDB.SaveLightClientBootstrap(ctx, blockRoot[:], bootstrap); err != nil {
 		return err
@@ -122,10 +151,23 @@ func (s *Store) SaveLightClientUpdate(ctx context.Context, period uint64, update
 	return nil
 }
 
-func (s *Store) SetLastFinalityUpdate(update interfaces.LightClientFinalityUpdate) {
+func (s *Store) SetLastFinalityUpdate(update interfaces.LightClientFinalityUpdate, broadcast bool) {
 	s.mu.Lock()
 	defer s.mu.Unlock()
+
+	if broadcast && IsFinalityUpdateValidForBroadcast(update, s.lastFinalityUpdate) {
+		if err := s.p2p.BroadcastLightClientFinalityUpdate(context.Background(), update); err != nil {
+			log.WithError(err).Error("Could not broadcast light client finality update")
+		}
+	}
+
 	s.lastFinalityUpdate = update
+	log.Debug("Saved new light client finality update")
+
+	s.stateFeed.Send(&feed.Event{
+		Type: statefeed.LightClientFinalityUpdate,
+		Data: update,
+	})
 }
 
 func (s *Store) LastFinalityUpdate() interfaces.LightClientFinalityUpdate {
@@ -134,10 +176,23 @@ func (s *Store) LastFinalityUpdate() interfaces.LightClientFinalityUpdate {
 	return s.lastFinalityUpdate
 }
 
-func (s *Store) SetLastOptimisticUpdate(update interfaces.LightClientOptimisticUpdate) {
+func (s *Store) SetLastOptimisticUpdate(update interfaces.LightClientOptimisticUpdate, broadcast bool) {
 	s.mu.Lock()
 	defer s.mu.Unlock()
+
+	if broadcast {
+		if err := s.p2p.BroadcastLightClientOptimisticUpdate(context.Background(), update); err != nil {
+			log.WithError(err).Error("Could not broadcast light client optimistic update")
+		}
+	}
+
 	s.lastOptimisticUpdate = update
+	log.Debug("Saved new light client optimistic update")
+
+	s.stateFeed.Send(&feed.Event{
+		Type: statefeed.LightClientOptimisticUpdate,
+		Data: update,
+	})
 }
 
 func (s *Store) LastOptimisticUpdate() interfaces.LightClientOptimisticUpdate {

beacon-chain/core/light-client/store_test.go

@@ -3,7 +3,10 @@ package light_client_test
 import (
 	"testing"
 
+	"github.com/OffchainLabs/prysm/v6/async/event"
 	lightClient "github.com/OffchainLabs/prysm/v6/beacon-chain/core/light-client"
+	testDB "github.com/OffchainLabs/prysm/v6/beacon-chain/db/testing"
+	p2pTesting "github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/testing"
 	"github.com/OffchainLabs/prysm/v6/config/params"
 	"github.com/OffchainLabs/prysm/v6/runtime/version"
 	"github.com/OffchainLabs/prysm/v6/testing/require"
@@ -21,22 +24,22 @@ func TestLightClientStore(t *testing.T) {
 	params.OverrideBeaconConfig(cfg)
 
 	// Initialize the light client store
-	lcStore := &lightClient.Store{}
+	lcStore := lightClient.NewLightClientStore(testDB.SetupDB(t), &p2pTesting.FakeP2P{}, new(event.Feed))
 
 	// Create test light client updates for Capella and Deneb
 	lCapella := util.NewTestLightClient(t, version.Capella)
-	opUpdateCapella, err := lightClient.NewLightClientOptimisticUpdateFromBeaconState(lCapella.Ctx, lCapella.State.Slot(), lCapella.State, lCapella.Block, lCapella.AttestedState, lCapella.AttestedBlock)
+	opUpdateCapella, err := lightClient.NewLightClientOptimisticUpdateFromBeaconState(lCapella.Ctx, lCapella.State, lCapella.Block, lCapella.AttestedState, lCapella.AttestedBlock)
 	require.NoError(t, err)
 	require.NotNil(t, opUpdateCapella, "OptimisticUpdateCapella is nil")
-	finUpdateCapella, err := lightClient.NewLightClientFinalityUpdateFromBeaconState(lCapella.Ctx, lCapella.State.Slot(), lCapella.State, lCapella.Block, lCapella.AttestedState, lCapella.AttestedBlock, lCapella.FinalizedBlock)
+	finUpdateCapella, err := lightClient.NewLightClientFinalityUpdateFromBeaconState(lCapella.Ctx, lCapella.State, lCapella.Block, lCapella.AttestedState, lCapella.AttestedBlock, lCapella.FinalizedBlock)
 	require.NoError(t, err)
 	require.NotNil(t, finUpdateCapella, "FinalityUpdateCapella is nil")
 
 	lDeneb := util.NewTestLightClient(t, version.Deneb)
-	opUpdateDeneb, err := lightClient.NewLightClientOptimisticUpdateFromBeaconState(lDeneb.Ctx, lDeneb.State.Slot(), lDeneb.State, lDeneb.Block, lDeneb.AttestedState, lDeneb.AttestedBlock)
+	opUpdateDeneb, err := lightClient.NewLightClientOptimisticUpdateFromBeaconState(lDeneb.Ctx, lDeneb.State, lDeneb.Block, lDeneb.AttestedState, lDeneb.AttestedBlock)
 	require.NoError(t, err)
 	require.NotNil(t, opUpdateDeneb, "OptimisticUpdateDeneb is nil")
-	finUpdateDeneb, err := lightClient.NewLightClientFinalityUpdateFromBeaconState(lDeneb.Ctx, lDeneb.State.Slot(), lDeneb.State, lDeneb.Block, lDeneb.AttestedState, lDeneb.AttestedBlock, lDeneb.FinalizedBlock)
+	finUpdateDeneb, err := lightClient.NewLightClientFinalityUpdateFromBeaconState(lDeneb.Ctx, lDeneb.State, lDeneb.Block, lDeneb.AttestedState, lDeneb.AttestedBlock, lDeneb.FinalizedBlock)
 	require.NoError(t, err)
 	require.NotNil(t, finUpdateDeneb, "FinalityUpdateDeneb is nil")
 
@@ -45,24 +48,118 @@ func TestLightClientStore(t *testing.T) {
 	require.IsNil(t, lcStore.LastOptimisticUpdate(), "lastOptimisticUpdate should be nil")
 
 	// Set and get finality with Capella update. Optimistic update should be nil
-	lcStore.SetLastFinalityUpdate(finUpdateCapella)
+	lcStore.SetLastFinalityUpdate(finUpdateCapella, false)
 	require.Equal(t, finUpdateCapella, lcStore.LastFinalityUpdate(), "lastFinalityUpdate is wrong")
 	require.IsNil(t, lcStore.LastOptimisticUpdate(), "lastOptimisticUpdate should be nil")
 
 	// Set and get optimistic with Capella update. Finality update should be Capella
-	lcStore.SetLastOptimisticUpdate(opUpdateCapella)
+	lcStore.SetLastOptimisticUpdate(opUpdateCapella, false)
 	require.Equal(t, opUpdateCapella, lcStore.LastOptimisticUpdate(), "lastOptimisticUpdate is wrong")
 	require.Equal(t, finUpdateCapella, lcStore.LastFinalityUpdate(), "lastFinalityUpdate is wrong")
 
 	// Set and get finality and optimistic with Deneb update
-	lcStore.SetLastFinalityUpdate(finUpdateDeneb)
-	lcStore.SetLastOptimisticUpdate(opUpdateDeneb)
+	lcStore.SetLastFinalityUpdate(finUpdateDeneb, false)
+	lcStore.SetLastOptimisticUpdate(opUpdateDeneb, false)
 	require.Equal(t, finUpdateDeneb, lcStore.LastFinalityUpdate(), "lastFinalityUpdate is wrong")
 	require.Equal(t, opUpdateDeneb, lcStore.LastOptimisticUpdate(), "lastOptimisticUpdate is wrong")
-
-	// Set and get finality and optimistic with nil update
-	lcStore.SetLastFinalityUpdate(nil)
-	lcStore.SetLastOptimisticUpdate(nil)
-	require.IsNil(t, lcStore.LastFinalityUpdate(), "lastFinalityUpdate should be nil")
-	require.IsNil(t, lcStore.LastOptimisticUpdate(), "lastOptimisticUpdate should be nil")
+}
+
+func TestLightClientStore_SetLastFinalityUpdate(t *testing.T) {
+	p2p := p2pTesting.NewTestP2P(t)
+	lcStore := lightClient.NewLightClientStore(testDB.SetupDB(t), p2p, new(event.Feed))
+
+	// update 0 with basic data and no supermajority following an empty lastFinalityUpdate - should save and broadcast
+	l0 := util.NewTestLightClient(t, version.Altair)
+	update0, err := lightClient.NewLightClientFinalityUpdateFromBeaconState(l0.Ctx, l0.State, l0.Block, l0.AttestedState, l0.AttestedBlock, l0.FinalizedBlock)
+	require.NoError(t, err, "Failed to create light client finality update")
+
+	require.Equal(t, true, lightClient.IsBetterFinalityUpdate(update0, lcStore.LastFinalityUpdate()), "update0 should be better than nil")
+	// update0 should be valid for broadcast - meaning it should be broadcasted
+	require.Equal(t, true, lightClient.IsFinalityUpdateValidForBroadcast(update0, lcStore.LastFinalityUpdate()), "update0 should be valid for broadcast")
+
+	lcStore.SetLastFinalityUpdate(update0, true)
+	require.Equal(t, update0, lcStore.LastFinalityUpdate(), "lastFinalityUpdate should match the set value")
+	require.Equal(t, true, p2p.BroadcastCalled.Load(), "Broadcast should have been called after setting a new last finality update when previous is nil")
+	p2p.BroadcastCalled.Store(false) // Reset for next test
+
+	// update 1 with same finality slot, increased attested slot, and no supermajority - should save but not broadcast
+	l1 := util.NewTestLightClient(t, version.Altair, util.WithIncreasedAttestedSlot(1))
+	update1, err := lightClient.NewLightClientFinalityUpdateFromBeaconState(l1.Ctx, l1.State, l1.Block, l1.AttestedState, l1.AttestedBlock, l1.FinalizedBlock)
+	require.NoError(t, err, "Failed to create light client finality update")
+
+	require.Equal(t, true, lightClient.IsBetterFinalityUpdate(update1, update0), "update1 should be better than update0")
+	// update1 should not be valid for broadcast - meaning it should not be broadcasted
+	require.Equal(t, false, lightClient.IsFinalityUpdateValidForBroadcast(update1, lcStore.LastFinalityUpdate()), "update1 should not be valid for broadcast")
+
+	lcStore.SetLastFinalityUpdate(update1, true)
+	require.Equal(t, update1, lcStore.LastFinalityUpdate(), "lastFinalityUpdate should match the set value")
+	require.Equal(t, false, p2p.BroadcastCalled.Load(), "Broadcast should not have been called after setting a new last finality update without supermajority")
+	p2p.BroadcastCalled.Store(false) // Reset for next test
+
+	// update 2 with same finality slot, increased attested slot, and supermajority - should save and broadcast
+	l2 := util.NewTestLightClient(t, version.Altair, util.WithIncreasedAttestedSlot(2), util.WithSupermajority())
+	update2, err := lightClient.NewLightClientFinalityUpdateFromBeaconState(l2.Ctx, l2.State, l2.Block, l2.AttestedState, l2.AttestedBlock, l2.FinalizedBlock)
+	require.NoError(t, err, "Failed to create light client finality update")
+
+	require.Equal(t, true, lightClient.IsBetterFinalityUpdate(update2, update1), "update2 should be better than update1")
+	// update2 should be valid for broadcast - meaning it should be broadcasted
+	require.Equal(t, true, lightClient.IsFinalityUpdateValidForBroadcast(update2, lcStore.LastFinalityUpdate()), "update2 should be valid for broadcast")
+
+	lcStore.SetLastFinalityUpdate(update2, true)
+	require.Equal(t, update2, lcStore.LastFinalityUpdate(), "lastFinalityUpdate should match the set value")
+	require.Equal(t, true, p2p.BroadcastCalled.Load(), "Broadcast should have been called after setting a new last finality update with supermajority")
+	p2p.BroadcastCalled.Store(false) // Reset for next test
+
+	// update 3 with same finality slot, increased attested slot, and supermajority - should save but not broadcast
+	l3 := util.NewTestLightClient(t, version.Altair, util.WithIncreasedAttestedSlot(3), util.WithSupermajority())
+	update3, err := lightClient.NewLightClientFinalityUpdateFromBeaconState(l3.Ctx, l3.State, l3.Block, l3.AttestedState, l3.AttestedBlock, l3.FinalizedBlock)
+	require.NoError(t, err, "Failed to create light client finality update")
+
+	require.Equal(t, true, lightClient.IsBetterFinalityUpdate(update3, update2), "update3 should be better than update2")
+	// update3 should not be valid for broadcast - meaning it should not be broadcasted
+	require.Equal(t, false, lightClient.IsFinalityUpdateValidForBroadcast(update3, lcStore.LastFinalityUpdate()), "update3 should not be valid for broadcast")
+
+	lcStore.SetLastFinalityUpdate(update3, true)
+	require.Equal(t, update3, lcStore.LastFinalityUpdate(), "lastFinalityUpdate should match the set value")
+	require.Equal(t, false, p2p.BroadcastCalled.Load(), "Broadcast should not have been when previous was already broadcast")
+
+	// update 4 with increased finality slot, increased attested slot, and supermajority - should save and broadcast
+	l4 := util.NewTestLightClient(t, version.Altair, util.WithIncreasedFinalizedSlot(1), util.WithIncreasedAttestedSlot(1), util.WithSupermajority())
+	update4, err := lightClient.NewLightClientFinalityUpdateFromBeaconState(l4.Ctx, l4.State, l4.Block, l4.AttestedState, l4.AttestedBlock, l4.FinalizedBlock)
+	require.NoError(t, err, "Failed to create light client finality update")
+
+	require.Equal(t, true, lightClient.IsBetterFinalityUpdate(update4, update3), "update4 should be better than update3")
+	// update4 should be valid for broadcast - meaning it should be broadcasted
+	require.Equal(t, true, lightClient.IsFinalityUpdateValidForBroadcast(update4, lcStore.LastFinalityUpdate()), "update4 should be valid for broadcast")
+
+	lcStore.SetLastFinalityUpdate(update4, true)
+	require.Equal(t, update4, lcStore.LastFinalityUpdate(), "lastFinalityUpdate should match the set value")
+	require.Equal(t, true, p2p.BroadcastCalled.Load(), "Broadcast should have been called after a new finality update with increased finality slot")
+	p2p.BroadcastCalled.Store(false) // Reset for next test
+
+	// update 5 with the same new finality slot, increased attested slot, and supermajority - should save but not broadcast
+	l5 := util.NewTestLightClient(t, version.Altair, util.WithIncreasedFinalizedSlot(1), util.WithIncreasedAttestedSlot(2), util.WithSupermajority())
+	update5, err := lightClient.NewLightClientFinalityUpdateFromBeaconState(l5.Ctx, l5.State, l5.Block, l5.AttestedState, l5.AttestedBlock, l5.FinalizedBlock)
+	require.NoError(t, err, "Failed to create light client finality update")
+
+	require.Equal(t, true, lightClient.IsBetterFinalityUpdate(update5, update4), "update5 should be better than update4")
+	// update5 should not be valid for broadcast - meaning it should not be broadcasted
+	require.Equal(t, false, lightClient.IsFinalityUpdateValidForBroadcast(update5, lcStore.LastFinalityUpdate()), "update5 should not be valid for broadcast")
+
+	lcStore.SetLastFinalityUpdate(update5, true)
+	require.Equal(t, update5, lcStore.LastFinalityUpdate(), "lastFinalityUpdate should match the set value")
+	require.Equal(t, false, p2p.BroadcastCalled.Load(), "Broadcast should not have been called when previous was already broadcast with supermajority")
+
+	// update 6 with the same new finality slot, increased attested slot, and no supermajority - should save but not broadcast
+	l6 := util.NewTestLightClient(t, version.Altair, util.WithIncreasedFinalizedSlot(1), util.WithIncreasedAttestedSlot(3))
+	update6, err := lightClient.NewLightClientFinalityUpdateFromBeaconState(l6.Ctx, l6.State, l6.Block, l6.AttestedState, l6.AttestedBlock, l6.FinalizedBlock)
+	require.NoError(t, err, "Failed to create light client finality update")
+
+	require.Equal(t, true, lightClient.IsBetterFinalityUpdate(update6, update5), "update6 should be better than update5")
+	// update6 should not be valid for broadcast - meaning it should not be broadcasted
+	require.Equal(t, false, lightClient.IsFinalityUpdateValidForBroadcast(update6, lcStore.LastFinalityUpdate()), "update6 should not be valid for broadcast")
+
+	lcStore.SetLastFinalityUpdate(update6, true)
+	require.Equal(t, update6, lcStore.LastFinalityUpdate(), "lastFinalityUpdate should match the set value")
+	require.Equal(t, false, p2p.BroadcastCalled.Load(), "Broadcast should not have been called when previous was already broadcast with supermajority")
 }

beacon-chain/core/peerdas/das_core.go

@@ -41,17 +41,17 @@ const (
 // CustodyGroups computes the custody groups the node should participate in for custody.
 // https://github.com/ethereum/consensus-specs/blob/v1.5.0-beta.5/specs/fulu/das-core.md#get_custody_groups
 func CustodyGroups(nodeId enode.ID, custodyGroupCount uint64) ([]uint64, error) {
-	numberOfCustodyGroup := params.BeaconConfig().NumberOfCustodyGroups
+	numberOfCustodyGroups := params.BeaconConfig().NumberOfCustodyGroups
 
 	// Check if the custody group count is larger than the number of custody groups.
-	if custodyGroupCount > numberOfCustodyGroup {
+	if custodyGroupCount > numberOfCustodyGroups {
 		return nil, ErrCustodyGroupCountTooLarge
 	}
 
 	// Shortcut if all custody groups are needed.
-	if custodyGroupCount == numberOfCustodyGroup {
-		custodyGroups := make([]uint64, 0, numberOfCustodyGroup)
-		for i := range numberOfCustodyGroup {
+	if custodyGroupCount == numberOfCustodyGroups {
+		custodyGroups := make([]uint64, 0, numberOfCustodyGroups)
+		for i := range numberOfCustodyGroups {
 			custodyGroups = append(custodyGroups, i)
 		}
 
@@ -73,7 +73,7 @@ func CustodyGroups(nodeId enode.ID, custodyGroupCount uint64) ([]uint64, error)
 		hashedCurrentId := hash.Hash(currentIdBytesLittleEndian)
 
 		// Get the custody group ID.
-		custodyGroup := binary.LittleEndian.Uint64(hashedCurrentId[:8]) % numberOfCustodyGroup
+		custodyGroup := binary.LittleEndian.Uint64(hashedCurrentId[:8]) % numberOfCustodyGroups
 
 		// Add the custody group to the map.
 		if !custodyGroupsMap[custodyGroup] {
@@ -88,9 +88,6 @@ func CustodyGroups(nodeId enode.ID, custodyGroupCount uint64) ([]uint64, error)
 			// Increment the current ID.
 			currentId.Add(currentId, one)
 		}
-
-		// Sort the custody groups.
-		slices.Sort[[]uint64](custodyGroups)
 	}
 
 	// Final check.
@@ -98,6 +95,9 @@ func CustodyGroups(nodeId enode.ID, custodyGroupCount uint64) ([]uint64, error)
 		return nil, errWrongComputedCustodyGroupCount
 	}
 
+	// Sort the custody groups.
+	slices.Sort[[]uint64](custodyGroups)
+
 	return custodyGroups, nil
 }
 
@@ -105,19 +105,19 @@ func CustodyGroups(nodeId enode.ID, custodyGroupCount uint64) ([]uint64, error)
 // https://github.com/ethereum/consensus-specs/blob/v1.5.0-beta.5/specs/fulu/das-core.md#compute_columns_for_custody_group
 func ComputeColumnsForCustodyGroup(custodyGroup uint64) ([]uint64, error) {
 	beaconConfig := params.BeaconConfig()
-	numberOfCustodyGroup := beaconConfig.NumberOfCustodyGroups
+	numberOfCustodyGroups := beaconConfig.NumberOfCustodyGroups
 
-	if custodyGroup >= numberOfCustodyGroup {
+	if custodyGroup >= numberOfCustodyGroups {
 		return nil, ErrCustodyGroupTooLarge
 	}
 
 	numberOfColumns := beaconConfig.NumberOfColumns
 
-	columnsPerGroup := numberOfColumns / numberOfCustodyGroup
+	columnsPerGroup := numberOfColumns / numberOfCustodyGroups
 
 	columns := make([]uint64, 0, columnsPerGroup)
 	for i := range columnsPerGroup {
-		column := numberOfCustodyGroup*i + custodyGroup
+		column := numberOfCustodyGroups*i + custodyGroup
 		columns = append(columns, column)
 	}
 
@@ -127,7 +127,7 @@ func ComputeColumnsForCustodyGroup(custodyGroup uint64) ([]uint64, error) {
 // DataColumnSidecars computes the data column sidecars from the signed block, cells and cell proofs.
 // The returned value contains pointers to function parameters.
 // (If the caller alterates `cellsAndProofs` afterwards, the returned value will be modified as well.)
-// https://github.com/ethereum/consensus-specs/blob/v1.5.0-beta.3/specs/fulu/das-core.md#get_data_column_sidecars
+// https://github.com/ethereum/consensus-specs/blob/v1.6.0-alpha.3/specs/fulu/validator.md#get_data_column_sidecars_from_block
 func DataColumnSidecars(signedBlock interfaces.ReadOnlySignedBeaconBlock, cellsAndProofs []kzg.CellsAndProofs) ([]*ethpb.DataColumnSidecar, error) {
 	if signedBlock == nil || signedBlock.IsNil() || len(cellsAndProofs) == 0 {
 		return nil, nil
@@ -151,7 +151,7 @@ func DataColumnSidecars(signedBlock interfaces.ReadOnlySignedBeaconBlock, cellsA
 
 	kzgCommitmentsInclusionProof, err := blocks.MerkleProofKZGCommitments(blockBody)
 	if err != nil {
-		return nil, errors.Wrap(err, "merkle proof ZKG commitments")
+		return nil, errors.Wrap(err, "merkle proof KZG commitments")
 	}
 
 	dataColumnSidecars, err := dataColumnsSidecars(signedBlockHeader, blobKzgCommitments, kzgCommitmentsInclusionProof, cellsAndProofs)
@@ -219,6 +219,7 @@ func CustodyColumns(custodyGroups []uint64) (map[uint64]bool, error) {
 // the KZG commitment includion proofs and cells and cell proofs.
 // The returned value contains pointers to function parameters.
 // (If the caller alterates input parameters afterwards, the returned value will be modified as well.)
+// https://github.com/ethereum/consensus-specs/blob/v1.6.0-alpha.3/specs/fulu/validator.md#get_data_column_sidecars
 func dataColumnsSidecars(
 	signedBlockHeader *ethpb.SignedBeaconBlockHeader,
 	blobKzgCommitments [][]byte,

beacon-chain/core/peerdas/das_core_test.go

@@ -17,8 +17,8 @@ func TestCustodyGroups(t *testing.T) {
 	// --------------------------------------------
 	// The happy path is unit tested in spec tests.
 	// --------------------------------------------
-	numberOfCustodyGroup := params.BeaconConfig().NumberOfCustodyGroups
-	_, err := peerdas.CustodyGroups(enode.ID{}, numberOfCustodyGroup+1)
+	numberOfCustodyGroups := params.BeaconConfig().NumberOfCustodyGroups
+	_, err := peerdas.CustodyGroups(enode.ID{}, numberOfCustodyGroups+1)
 	require.ErrorIs(t, err, peerdas.ErrCustodyGroupCountTooLarge)
 }
 
@@ -26,8 +26,8 @@ func TestComputeColumnsForCustodyGroup(t *testing.T) {
 	// --------------------------------------------
 	// The happy path is unit tested in spec tests.
 	// --------------------------------------------
-	numberOfCustodyGroup := params.BeaconConfig().NumberOfCustodyGroups
-	_, err := peerdas.ComputeColumnsForCustodyGroup(numberOfCustodyGroup)
+	numberOfCustodyGroups := params.BeaconConfig().NumberOfCustodyGroups
+	_, err := peerdas.ComputeColumnsForCustodyGroup(numberOfCustodyGroups)
 	require.ErrorIs(t, err, peerdas.ErrCustodyGroupTooLarge)
 }
 

beacon-chain/core/peerdas/reconstruction.go

@@ -123,7 +123,7 @@ func ReconstructDataColumnSidecars(inVerifiedRoSidecars []blocks.VerifiedRODataC
 
 // ConstructDataColumnSidecars constructs data column sidecars from a block, (un-extended) blobs and
 // cell proofs corresponding the extended blobs. The main purpose of this function is to
-// construct data columns sidecars from data obtained from the execution client via:
+// construct data column sidecars from data obtained from the execution client via:
 // - `engine_getBlobsV2` - https://github.com/ethereum/execution-apis/blob/main/src/engine/osaka.md#engine_getblobsv2, or
 // - `engine_getPayloadV5` - https://github.com/ethereum/execution-apis/blob/main/src/engine/osaka.md#engine_getpayloadv5
 // Note: In this function, to stick with the `BlobsBundleV2` format returned by the execution client in `engine_getPayloadV5`,
@@ -222,8 +222,8 @@ func ReconstructBlobs(block blocks.ROBlock, verifiedDataColumnSidecars []blocks.
 	// Check if the data column sidecars are aligned with the block.
 	dataColumnSidecars := make([]blocks.RODataColumn, 0, len(verifiedDataColumnSidecars))
 	for _, verifiedDataColumnSidecar := range verifiedDataColumnSidecars {
-		dataColumnSicecar := verifiedDataColumnSidecar.RODataColumn
-		dataColumnSidecars = append(dataColumnSidecars, dataColumnSicecar)
+		dataColumnSidecar := verifiedDataColumnSidecar.RODataColumn
+		dataColumnSidecars = append(dataColumnSidecars, dataColumnSidecar)
 	}
 
 	if err := DataColumnsAlignWithBlock(block, dataColumnSidecars); err != nil {
@@ -241,7 +241,7 @@ func ReconstructBlobs(block blocks.ROBlock, verifiedDataColumnSidecars []blocks.
 		return blobSidecars, nil
 	}
 
-	// We need to reconstruct the blobs.
+	// We need to reconstruct the data column sidecars.
 	reconstructedDataColumnSidecars, err := ReconstructDataColumnSidecars(verifiedDataColumnSidecars)
 	if err != nil {
 		return nil, errors.Wrap(err, "reconstruct data column sidecars")

beacon-chain/core/peerdas/reconstruction_test.go

@@ -196,6 +196,26 @@ func TestReconstructBlobs(t *testing.T) {
 		require.ErrorIs(t, err, peerdas.ErrDataColumnSidecarsNotSortedByIndex)
 	})
 
+	t.Run("consecutive duplicates", func(t *testing.T) {
+		_, _, verifiedRoSidecars := util.GenerateTestFuluBlockWithSidecars(t, 3)
+
+		// [0, 1, 1, 3, 4, ...]
+		verifiedRoSidecars[2] = verifiedRoSidecars[1]
+
+		_, err := peerdas.ReconstructBlobs(emptyBlock, verifiedRoSidecars, []int{0})
+		require.ErrorIs(t, err, peerdas.ErrDataColumnSidecarsNotSortedByIndex)
+	})
+
+	t.Run("non-consecutive duplicates", func(t *testing.T) {
+		_, _, verifiedRoSidecars := util.GenerateTestFuluBlockWithSidecars(t, 3)
+
+		// [0, 1, 2, 1, 4, ...]
+		verifiedRoSidecars[3] = verifiedRoSidecars[1]
+
+		_, err := peerdas.ReconstructBlobs(emptyBlock, verifiedRoSidecars, []int{0})
+		require.ErrorIs(t, err, peerdas.ErrDataColumnSidecarsNotSortedByIndex)
+	})
+
 	t.Run("not enough columns", func(t *testing.T) {
 		_, _, verifiedRoSidecars := util.GenerateTestFuluBlockWithSidecars(t, 3)
 

beacon-chain/core/peerdas/validator.go

@@ -21,10 +21,10 @@ func ValidatorsCustodyRequirement(state beaconState.ReadOnlyBeaconState, validat
 	}
 
 	beaconConfig := params.BeaconConfig()
-	numberOfCustodyGroup := beaconConfig.NumberOfCustodyGroups
+	numberOfCustodyGroups := beaconConfig.NumberOfCustodyGroups
 	validatorCustodyRequirement := beaconConfig.ValidatorCustodyRequirement
 	balancePerAdditionalCustodyGroup := beaconConfig.BalancePerAdditionalCustodyGroup
 
 	count := totalNodeBalance / balancePerAdditionalCustodyGroup
-	return min(max(count, validatorCustodyRequirement), numberOfCustodyGroup), nil
+	return min(max(count, validatorCustodyRequirement), numberOfCustodyGroups), nil
 }

beacon-chain/das/availability_columns.go

@@ -126,11 +126,11 @@ func (s *LazilyPersistentStoreColumn) IsDataAvailable(ctx context.Context, curre
 		return errors.Wrap(err, "entry filter")
 	}
 
-	// https://github.com/ethereum/consensus-specs/blob/dev/specs/fulu/p2p-interface.md#datacolumnsidecarsbyrange-v1
+	// https://github.com/ethereum/consensus-specs/blob/master/specs/fulu/p2p-interface.md#datacolumnsidecarsbyrange-v1
 	verifier := s.newDataColumnsVerifier(roDataColumns, verification.ByRangeRequestDataColumnSidecarRequirements)
 
 	if err := verifier.ValidFields(); err != nil {
-		return errors.Wrap(err, "valid")
+		return errors.Wrap(err, "valid fields")
 	}
 
 	if err := verifier.SidecarInclusionProven(); err != nil {
@@ -164,7 +164,7 @@ func (s *LazilyPersistentStoreColumn) fullCommitmentsToCheck(nodeID enode.ID, bl
 	blockSlot := block.Block().Slot()
 	blockEpoch := slots.ToEpoch(blockSlot)
 
-	// Compute the current spoch.
+	// Compute the current epoch.
 	currentEpoch := slots.ToEpoch(currentSlot)
 
 	// Return early if the request is out of the MIN_EPOCHS_FOR_DATA_COLUMN_SIDECARS_REQUESTS window.

beacon-chain/db/filesystem/data_column.go

@@ -251,7 +251,7 @@ func (dcs *DataColumnStorage) Summary(root [fieldparams.RootLength]byte) DataCol
 }
 
 // Save saves data column sidecars into the database and asynchronously performs pruning.
-// The returned chanel is closed when the pruning is complete.
+// The returned channel is closed when the pruning is complete.
 func (dcs *DataColumnStorage) Save(dataColumnSidecars []blocks.VerifiedRODataColumn) error {
 	startTime := time.Now()
 
@@ -266,8 +266,7 @@ func (dcs *DataColumnStorage) Save(dataColumnSidecars []blocks.VerifiedRODataCol
 		return errWrongNumberOfColumns
 	}
 
-	highestEpoch := primitives.Epoch(0)
-	dataColumnSidecarsbyRoot := make(map[[fieldparams.RootLength]byte][]blocks.VerifiedRODataColumn)
+	dataColumnSidecarsByRoot := make(map[[fieldparams.RootLength]byte][]blocks.VerifiedRODataColumn)
 
 	// Group data column sidecars by root.
 	for _, dataColumnSidecar := range dataColumnSidecars {
@@ -278,23 +277,20 @@ func (dcs *DataColumnStorage) Save(dataColumnSidecars []blocks.VerifiedRODataCol
 
 		// Group data column sidecars by root.
 		root := dataColumnSidecar.BlockRoot()
-		dataColumnSidecarsbyRoot[root] = append(dataColumnSidecarsbyRoot[root], dataColumnSidecar)
+		dataColumnSidecarsByRoot[root] = append(dataColumnSidecarsByRoot[root], dataColumnSidecar)
 	}
 
-	for root, dataColumnSidecars := range dataColumnSidecarsbyRoot {
+	for root, dataColumnSidecars := range dataColumnSidecarsByRoot {
 		// Safety check all data column sidecars for this root are from the same slot.
-		firstSlot := dataColumnSidecars[0].SignedBlockHeader.Header.Slot
+		slot := dataColumnSidecars[0].Slot()
 		for _, dataColumnSidecar := range dataColumnSidecars[1:] {
-			if dataColumnSidecar.SignedBlockHeader.Header.Slot != firstSlot {
+			if dataColumnSidecar.Slot() != slot {
 				return errDataColumnSidecarsFromDifferentSlots
 			}
 		}
 
-		// Set the highest epoch.
-		epoch := slots.ToEpoch(dataColumnSidecars[0].Slot())
-		highestEpoch = max(highestEpoch, epoch)
-
 		// Save data columns in the filesystem.
+		epoch := slots.ToEpoch(slot)
 		if err := dcs.saveFilesystem(root, epoch, dataColumnSidecars); err != nil {
 			return errors.Wrap(err, "save filesystem")
 		}
@@ -306,7 +302,7 @@ func (dcs *DataColumnStorage) Save(dataColumnSidecars []blocks.VerifiedRODataCol
 		}
 
 		// Compute the data columns ident.
-		dataColumnsIdent := DataColumnsIdent{Root: root, Epoch: slots.ToEpoch(dataColumnSidecars[0].Slot()), Indices: indices}
+		dataColumnsIdent := DataColumnsIdent{Root: root, Epoch: epoch, Indices: indices}
 
 		// Set data columns in the cache.
 		if err := dcs.cache.set(dataColumnsIdent); err != nil {

beacon-chain/db/filesystem/doc.go

@@ -20,7 +20,7 @@ File organisation
   The remaining 7 bits (from 0 to 127) represent the index of the data column.
   This sentinel bit is needed to distinguish between the column with index 0 and no column.
   Example: If the column with index 5 is in the 3th position in the file, then indices[5] = 0x80 + 0x03 = 0x83.
-- The rest of the file is a repeat of the SSZ encoded data columns sidecars.
+- The rest of the file is a repeat of the SSZ encoded data column sidecars.
 
 
 |------------------------------------------|------------------------------------------------------------------------------------|
@@ -75,7 +75,7 @@ data-columns
 
 Computation of the maximum size of a DataColumnSidecar
 ------------------------------------------------------
-https://github.com/ethereum/consensus-specs/blob/dev/specs/fulu/das-core.md#datacolumnsidecar
+https://github.com/ethereum/consensus-specs/blob/master/specs/fulu/das-core.md#datacolumnsidecar
 
 
 class DataColumnSidecar(Container):

beacon-chain/node/node.go

@@ -236,7 +236,7 @@ func New(cliCtx *cli.Context, cancel context.CancelFunc, opts ...Option) (*Beaco
 	beacon.finalizedStateAtStartUp = nil
 
 	if features.Get().EnableLightClient {
-		beacon.lcStore = lightclient.NewLightClientStore(beacon.db)
+		beacon.lcStore = lightclient.NewLightClientStore(beacon.db, beacon.fetchP2P(), beacon.StateFeed())
 	}
 
 	return beacon, nil
@@ -699,6 +699,7 @@ func (b *BeaconNode) registerP2P(cliCtx *cli.Context) error {
 		Discv5BootStrapAddrs: p2p.ParseBootStrapAddrs(bootstrapNodeAddrs),
 		RelayNodeAddr:        cliCtx.String(cmd.RelayNode.Name),
 		DataDir:              dataDir,
+		DiscoveryDir:         filepath.Join(dataDir, "discovery"),
 		LocalIP:              cliCtx.String(cmd.P2PIP.Name),
 		HostAddress:          cliCtx.String(cmd.P2PHost.Name),
 		HostDNS:              cliCtx.String(cmd.P2PHostDNS.Name),

beacon-chain/p2p/BUILD.bazel

@@ -104,6 +104,7 @@ go_library(
         "@com_github_libp2p_go_mplex//:go_default_library",
         "@com_github_multiformats_go_multiaddr//:go_default_library",
         "@com_github_multiformats_go_multiaddr//net:go_default_library",
+        "@com_github_patrickmn_go_cache//:go_default_library",
         "@com_github_pkg_errors//:go_default_library",
         "@com_github_prometheus_client_golang//prometheus:go_default_library",
         "@com_github_prometheus_client_golang//prometheus/promauto:go_default_library",
@@ -146,7 +147,6 @@ go_test(
         "//beacon-chain/blockchain/testing:go_default_library",
         "//beacon-chain/cache:go_default_library",
         "//beacon-chain/core/helpers:go_default_library",
-        "//beacon-chain/core/light-client:go_default_library",
         "//beacon-chain/core/peerdas:go_default_library",
         "//beacon-chain/core/signing:go_default_library",
         "//beacon-chain/db/testing:go_default_library",
@@ -173,7 +173,6 @@ go_test(
         "//proto/prysm/v1alpha1:go_default_library",
         "//proto/prysm/v1alpha1/metadata:go_default_library",
         "//proto/testing:go_default_library",
-        "//runtime/version:go_default_library",
         "//testing/assert:go_default_library",
         "//testing/require:go_default_library",
         "//testing/util:go_default_library",

beacon-chain/p2p/broadcaster.go

@@ -24,6 +24,8 @@ import (
 	"google.golang.org/protobuf/proto"
 )
 
+const minimumPeersPerSubnetForBroadcast = 1
+
 // ErrMessageNotMapped occurs on a Broadcast attempt when a message has not been defined in the
 // GossipTypeMapping.
 var ErrMessageNotMapped = errors.New("message type is not mapped to a PubSub topic")
@@ -124,15 +126,13 @@ func (s *Service) internalBroadcastAttestation(ctx context.Context, subnet uint6
 		if err := func() error {
 			s.subnetLocker(subnet).Lock()
 			defer s.subnetLocker(subnet).Unlock()
-			ok, err := s.FindPeersWithSubnet(ctx, attestationToTopic(subnet, forkDigest), subnet, 1)
-			if err != nil {
-				return err
+
+			if err := s.FindAndDialPeersWithSubnets(ctx, AttestationSubnetTopicFormat, forkDigest, minimumPeersPerSubnetForBroadcast, map[uint64]bool{subnet: true}); err != nil {
+				return errors.Wrap(err, "find peers with subnets")
 			}
-			if ok {
-				savedAttestationBroadcasts.Inc()
-				return nil
-			}
-			return errors.New("failed to find peers for subnet")
+
+			savedAttestationBroadcasts.Inc()
+			return nil
 		}(); err != nil {
 			log.WithError(err).Error("Failed to find peers")
 			tracing.AnnotateError(span, err)
@@ -183,15 +183,12 @@ func (s *Service) broadcastSyncCommittee(ctx context.Context, subnet uint64, sMs
 		if err := func() error {
 			s.subnetLocker(wrappedSubIdx).Lock()
 			defer s.subnetLocker(wrappedSubIdx).Unlock()
-			ok, err := s.FindPeersWithSubnet(ctx, syncCommitteeToTopic(subnet, forkDigest), subnet, 1)
-			if err != nil {
-				return err
+			if err := s.FindAndDialPeersWithSubnets(ctx, SyncCommitteeSubnetTopicFormat, forkDigest, minimumPeersPerSubnetForBroadcast, map[uint64]bool{subnet: true}); err != nil {
+				return errors.Wrap(err, "find peers with subnets")
 			}
-			if ok {
-				savedSyncCommitteeBroadcasts.Inc()
-				return nil
-			}
-			return errors.New("failed to find peers for subnet")
+
+			savedSyncCommitteeBroadcasts.Inc()
+			return nil
 		}(); err != nil {
 			log.WithError(err).Error("Failed to find peers")
 			tracing.AnnotateError(span, err)
@@ -250,15 +247,13 @@ func (s *Service) internalBroadcastBlob(ctx context.Context, subnet uint64, blob
 		if err := func() error {
 			s.subnetLocker(wrappedSubIdx).Lock()
 			defer s.subnetLocker(wrappedSubIdx).Unlock()
-			ok, err := s.FindPeersWithSubnet(ctx, blobSubnetToTopic(subnet, forkDigest), subnet, 1)
-			if err != nil {
-				return err
+
+			if err := s.FindAndDialPeersWithSubnets(ctx, BlobSubnetTopicFormat, forkDigest, minimumPeersPerSubnetForBroadcast, map[uint64]bool{subnet: true}); err != nil {
+				return errors.Wrap(err, "find peers with subnets")
 			}
-			if ok {
-				blobSidecarBroadcasts.Inc()
-				return nil
-			}
-			return errors.New("failed to find peers for subnet")
+
+			blobSidecarBroadcasts.Inc()
+			return nil
 		}(); err != nil {
 			log.WithError(err).Error("Failed to find peers")
 			tracing.AnnotateError(span, err)
@@ -329,7 +324,6 @@ func (s *Service) BroadcastDataColumn(
 	root [fieldparams.RootLength]byte,
 	dataColumnSubnet uint64,
 	dataColumnSidecar *ethpb.DataColumnSidecar,
-	peersCheckedChans ...chan<- bool, // Used for testing purposes to signal when peers are checked.
 ) error {
 	// Add tracing to the function.
 	ctx, span := trace.StartSpan(s.ctx, "p2p.BroadcastDataColumn")
@@ -349,7 +343,7 @@ func (s *Service) BroadcastDataColumn(
 	}
 
 	// Non-blocking broadcast, with attempts to discover a column subnet peer if none available.
-	go s.internalBroadcastDataColumn(ctx, root, dataColumnSubnet, dataColumnSidecar, forkDigest, peersCheckedChans)
+	go s.internalBroadcastDataColumn(ctx, root, dataColumnSubnet, dataColumnSidecar, forkDigest)
 
 	return nil
 }
@@ -360,7 +354,6 @@ func (s *Service) internalBroadcastDataColumn(
 	columnSubnet uint64,
 	dataColumnSidecar *ethpb.DataColumnSidecar,
 	forkDigest [fieldparams.VersionLength]byte,
-	peersCheckedChans []chan<- bool, // Used for testing purposes to signal when peers are checked.
 ) {
 	// Add tracing to the function.
 	_, span := trace.StartSpan(ctx, "p2p.internalBroadcastDataColumn")
@@ -382,7 +375,7 @@ func (s *Service) internalBroadcastDataColumn(
 	wrappedSubIdx := columnSubnet + dataColumnSubnetVal
 
 	// Find peers if needed.
-	if err := s.findPeersIfNeeded(ctx, wrappedSubIdx, topic, columnSubnet, peersCheckedChans); err != nil {
+	if err := s.findPeersIfNeeded(ctx, wrappedSubIdx, DataColumnSubnetTopicFormat, forkDigest, columnSubnet); err != nil {
 		log.WithError(err).Error("Failed to find peers for data column subnet")
 		tracing.AnnotateError(span, err)
 	}
@@ -416,35 +409,19 @@ func (s *Service) internalBroadcastDataColumn(
 func (s *Service) findPeersIfNeeded(
 	ctx context.Context,
 	wrappedSubIdx uint64,
-	topic string,
+	topicFormat string,
+	forkDigest [fieldparams.VersionLength]byte,
 	subnet uint64,
-	peersCheckedChans []chan<- bool, // Used for testing purposes to signal when peers are checked.
 ) error {
+	// Sending a data column sidecar to only one peer is not ideal,
+	// but it ensures at least one peer receives it.
 	s.subnetLocker(wrappedSubIdx).Lock()
 	defer s.subnetLocker(wrappedSubIdx).Unlock()
 
-	// Sending a data column sidecar to only one peer is not ideal,
-	// but it ensures at least one peer receives it.
-	const peerCount = 1
-
-	if s.hasPeerWithSubnet(topic) {
-		// Exit early if we already have peers with this subnet.
-		return nil
-	}
-
-	// Used for testing purposes.
-	if len(peersCheckedChans) > 0 {
-		peersCheckedChans[0] <- true
-	}
-
 	// No peers found, attempt to find peers with this subnet.
-	ok, err := s.FindPeersWithSubnet(ctx, topic, subnet, peerCount)
-	if err != nil {
+	if err := s.FindAndDialPeersWithSubnets(ctx, topicFormat, forkDigest, minimumPeersPerSubnetForBroadcast, map[uint64]bool{subnet: true}); err != nil {
 		return errors.Wrap(err, "find peers with subnet")
 	}
-	if !ok {
-		return errors.Errorf("failed to find peers for topic %s with subnet %d", topic, subnet)
-	}
 
 	return nil
 }

beacon-chain/p2p/broadcaster_test.go

@@ -11,7 +11,6 @@ import (
 
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/blockchain/kzg"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/helpers"
-	lightClient "github.com/OffchainLabs/prysm/v6/beacon-chain/core/light-client"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/peers"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/peers/scorers"
@@ -24,7 +23,6 @@ import (
 	"github.com/OffchainLabs/prysm/v6/network/forks"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	testpb "github.com/OffchainLabs/prysm/v6/proto/testing"
-	"github.com/OffchainLabs/prysm/v6/runtime/version"
 	"github.com/OffchainLabs/prysm/v6/testing/assert"
 	"github.com/OffchainLabs/prysm/v6/testing/require"
 	"github.com/OffchainLabs/prysm/v6/testing/util"
@@ -216,9 +214,10 @@ func TestService_BroadcastAttestation(t *testing.T) {
 }
 
 func TestService_BroadcastAttestationWithDiscoveryAttempts(t *testing.T) {
+	const port = uint(2000)
+
 	// Setup bootnode.
 	cfg := &Config{PingInterval: testPingInterval}
-	port := 2000
 	cfg.UDPPort = uint(port)
 	_, pkey := createAddrAndPrivKey(t)
 	ipAddr := net.ParseIP("127.0.0.1")
@@ -245,7 +244,7 @@ func TestService_BroadcastAttestationWithDiscoveryAttempts(t *testing.T) {
 		PingInterval:         testPingInterval,
 	}
 	// Setup 2 different hosts
-	for i := 1; i <= 2; i++ {
+	for i := uint(1); i <= 2; i++ {
 		h, pkey, ipAddr := createHost(t, port+i)
 		cfg.UDPPort = uint(port + i)
 		cfg.TCPPort = uint(port + i)
@@ -545,8 +544,7 @@ func TestService_BroadcastLightClientOptimisticUpdate(t *testing.T) {
 		}),
 	}
 
-	l := util.NewTestLightClient(t, version.Altair)
-	msg, err := lightClient.NewLightClientOptimisticUpdateFromBeaconState(l.Ctx, l.State.Slot(), l.State, l.Block, l.AttestedState, l.AttestedBlock)
+	msg, err := util.MockOptimisticUpdate()
 	require.NoError(t, err)
 
 	GossipTypeMapping[reflect.TypeOf(msg)] = LightClientOptimisticUpdateTopicFormat
@@ -612,8 +610,7 @@ func TestService_BroadcastLightClientFinalityUpdate(t *testing.T) {
 		}),
 	}
 
-	l := util.NewTestLightClient(t, version.Altair)
-	msg, err := lightClient.NewLightClientFinalityUpdateFromBeaconState(l.Ctx, l.State.Slot(), l.State, l.Block, l.AttestedState, l.AttestedBlock, l.FinalizedBlock)
+	msg, err := util.MockFinalityUpdate()
 	require.NoError(t, err)
 
 	GossipTypeMapping[reflect.TypeOf(msg)] = LightClientFinalityUpdateTopicFormat
@@ -687,7 +684,7 @@ func TestService_BroadcastDataColumn(t *testing.T) {
 	// Create a host.
 	_, pkey, ipAddr := createHost(t, port)
 
-	p := &Service{
+	service := &Service{
 		ctx:                   t.Context(),
 		host:                  p1.BHost,
 		pubsub:                p1.PubSub(),
@@ -701,56 +698,44 @@ func TestService_BroadcastDataColumn(t *testing.T) {
 	}
 
 	// Create a listener.
-	listener, err := p.startDiscoveryV5(ipAddr, pkey)
+	listener, err := service.startDiscoveryV5(ipAddr, pkey)
 	require.NoError(t, err)
 
-	p.dv5Listener = listener
+	service.dv5Listener = listener
 
-	digest, err := p.currentForkDigest()
+	digest, err := service.currentForkDigest()
 	require.NoError(t, err)
 
 	subnet := peerdas.ComputeSubnetForDataColumnSidecar(columnIndex)
-	topic := fmt.Sprintf(topicFormat, digest, subnet)
+	topic := fmt.Sprintf(topicFormat, digest, subnet) + service.Encoding().ProtocolSuffix()
 
 	roSidecars, _ := util.CreateTestVerifiedRoDataColumnSidecars(t, []util.DataColumnParam{{Index: columnIndex}})
 	sidecar := roSidecars[0].DataColumnSidecar
 
-	// Async listen for the pubsub, must be before the broadcast.
-	var wg sync.WaitGroup
-	wg.Add(1)
-
-	peersChecked := make(chan bool, 0)
-
-	go func(tt *testing.T) {
-		defer wg.Done()
-
-		ctx, cancel := context.WithTimeout(t.Context(), 5*time.Second)
-		defer cancel()
-
-		// Wait for the peers to be checked.
-		<-peersChecked
-
-		// External peer subscribes to the topic.
-		topic += p.Encoding().ProtocolSuffix()
-		sub, err := p2.SubscribeToTopic(topic)
-		require.NoError(tt, err)
-
-		msg, err := sub.Next(ctx)
-		require.NoError(tt, err)
-
-		var result ethpb.DataColumnSidecar
-		require.NoError(tt, p.Encoding().DecodeGossip(msg.Data, &result))
-		require.DeepEqual(tt, &result, sidecar)
-	}(t)
-
-	var emptyRoot [fieldparams.RootLength]byte
-
 	// Attempt to broadcast nil object should fail.
-	err = p.BroadcastDataColumn(emptyRoot, subnet, nil)
+	var emptyRoot [fieldparams.RootLength]byte
+	err = service.BroadcastDataColumn(emptyRoot, subnet, nil)
 	require.ErrorContains(t, "attempted to broadcast nil", err)
 
-	// Broadcast to peers and wait.
-	err = p.BroadcastDataColumn(emptyRoot, subnet, sidecar, peersChecked)
+	// Subscribe to the topic.
+	sub, err := p2.SubscribeToTopic(topic)
 	require.NoError(t, err)
-	require.Equal(t, false, util.WaitTimeout(&wg, 1*time.Minute), "Failed to receive pubsub within 1s")
+
+	// libp2p fails without this delay
+	time.Sleep(50 * time.Millisecond)
+
+	// Broadcast to peers and wait.
+	err = service.BroadcastDataColumn(emptyRoot, subnet, sidecar)
+	require.NoError(t, err)
+
+	// Receive the message.
+	ctx, cancel := context.WithTimeout(t.Context(), 5*time.Second)
+	defer cancel()
+
+	msg, err := sub.Next(ctx)
+	require.NoError(t, err)
+
+	var result ethpb.DataColumnSidecar
+	require.NoError(t, service.Encoding().DecodeGossip(msg.Data, &result))
+	require.DeepEqual(t, &result, sidecar)
 }

beacon-chain/p2p/config.go

@@ -27,6 +27,7 @@ type Config struct {
 	HostDNS              string
 	PrivateKey           string
 	DataDir              string
+	DiscoveryDir         string
 	MetaDataDir          string
 	QUICPort             uint
 	TCPPort              uint

beacon-chain/p2p/connection_gater.go

@@ -19,8 +19,7 @@ const (
 	// Burst limit for inbound dials.
 	ipBurst = 8
 
-	// High watermark buffer signifies the buffer till which
-	// we will handle inbound requests.
+	// High watermark buffer signifies the buffer till which we will handle inbound requests.
 	highWatermarkBuffer = 20
 )
 
@@ -53,7 +52,7 @@ func (s *Service) InterceptAccept(n network.ConnMultiaddrs) (allow bool) {
 			"reason": "exceeded dial limit"}).Trace("Not accepting inbound dial from ip address")
 		return false
 	}
-	if s.isPeerAtLimit(true /* inbound */) {
+	if s.isPeerAtLimit(inbound) {
 		log.WithFields(logrus.Fields{"peer": n.RemoteMultiaddr(),
 			"reason": "at peer limit"}).Trace("Not accepting inbound dial")
 		return false

beacon-chain/p2p/discovery.go

@@ -2,7 +2,9 @@ package p2p
 
 import (
 	"bytes"
+	"context"
 	"crypto/ecdsa"
+	"math"
 	"net"
 	"sync"
 	"time"
@@ -26,42 +28,54 @@ import (
 	"github.com/sirupsen/logrus"
 )
 
-type ListenerRebooter interface {
-	Listener
-	RebootListener() error
-}
+type (
+	// ListenerRebooter is an interface that extends the Listener interface
+	// with the `RebootListener` method.
+	ListenerRebooter interface {
+		Listener
+		RebootListener() error
+	}
 
-// Listener defines the discovery V5 network interface that is used
-// to communicate with other peers.
-type Listener interface {
-	Self() *enode.Node
-	Close()
-	Lookup(enode.ID) []*enode.Node
-	Resolve(*enode.Node) *enode.Node
-	RandomNodes() enode.Iterator
-	Ping(*enode.Node) error
-	RequestENR(*enode.Node) (*enode.Node, error)
-	LocalNode() *enode.LocalNode
-}
+	// Listener defines the discovery V5 network interface that is used
+	// to communicate with other peers.
+	Listener interface {
+		Self() *enode.Node
+		Close()
+		Lookup(enode.ID) []*enode.Node
+		Resolve(*enode.Node) *enode.Node
+		RandomNodes() enode.Iterator
+		Ping(*enode.Node) error
+		RequestENR(*enode.Node) (*enode.Node, error)
+		LocalNode() *enode.LocalNode
+	}
 
-const (
-	udp4 = iota
-	udp6
+	quicProtocol uint16
+
+	listenerWrapper struct {
+		mu              sync.RWMutex
+		listener        *discover.UDPv5
+		listenerCreator func() (*discover.UDPv5, error)
+	}
+
+	connectivityDirection int
+	udpVersion            int
 )
 
 const quickProtocolEnrKey = "quic"
 
-type quicProtocol uint16
+const (
+	udp4 udpVersion = iota
+	udp6
+)
+
+const (
+	inbound connectivityDirection = iota
+	all
+)
 
 // quicProtocol is the "quic" key, which holds the QUIC port of the node.
 func (quicProtocol) ENRKey() string { return quickProtocolEnrKey }
 
-type listenerWrapper struct {
-	mu              sync.RWMutex
-	listener        *discover.UDPv5
-	listenerCreator func() (*discover.UDPv5, error)
-}
-
 func newListener(listenerCreator func() (*discover.UDPv5, error)) (*listenerWrapper, error) {
 	rawListener, err := listenerCreator()
 	if err != nil {
@@ -276,29 +290,10 @@ func (s *Service) RefreshPersistentSubnets() {
 // listen for new nodes watches for new nodes in the network and adds them to the peerstore.
 func (s *Service) listenForNewNodes() {
 	const (
-		minLogInterval = 1 * time.Minute
 		thresholdLimit = 5
+		searchPeriod   = 20 * time.Second
 	)
 
-	peersSummary := func(threshold uint) (uint, uint) {
-		// Retrieve how many active peers we have.
-		activePeers := s.Peers().Active()
-		activePeerCount := uint(len(activePeers))
-
-		// Compute how many peers we are missing to reach the threshold.
-		if activePeerCount >= threshold {
-			return activePeerCount, 0
-		}
-
-		missingPeerCount := threshold - activePeerCount
-
-		return activePeerCount, missingPeerCount
-	}
-
-	var lastLogTime time.Time
-
-	iterator := s.dv5Listener.RandomNodes()
-	defer iterator.Close()
 	connectivityTicker := time.NewTicker(1 * time.Minute)
 	thresholdCount := 0
 
@@ -330,74 +325,148 @@ func (s *Service) listenForNewNodes() {
 					continue
 				}
 
-				iterator = s.dv5Listener.RandomNodes()
 				thresholdCount = 0
 			}
 		default:
-			if s.isPeerAtLimit(false /* inbound */) {
-				// Pause the main loop for a period to stop looking
-				// for new peers.
+			if s.isPeerAtLimit(all) {
+				// Pause the main loop for a period to stop looking for new peers.
 				log.Trace("Not looking for peers, at peer limit")
 				time.Sleep(pollingPeriod)
 				continue
 			}
 
-			// Compute the number of new peers we want to dial.
-			activePeerCount, missingPeerCount := peersSummary(s.cfg.MaxPeers)
-
-			fields := logrus.Fields{
-				"currentPeerCount": activePeerCount,
-				"targetPeerCount":  s.cfg.MaxPeers,
+			// Return early if the discovery listener isn't set.
+			if s.dv5Listener == nil {
+				return
 			}
 
-			if missingPeerCount == 0 {
-				log.Trace("Not looking for peers, at peer limit")
-				time.Sleep(pollingPeriod)
-				continue
-			}
+			func() {
+				ctx, cancel := context.WithTimeout(s.ctx, searchPeriod)
+				defer cancel()
 
-			if time.Since(lastLogTime) > minLogInterval {
-				lastLogTime = time.Now()
-				log.WithFields(fields).Debug("Searching for new active peers")
-			}
-
-			// Restrict dials if limit is applied.
-			if flags.MaxDialIsActive() {
-				maxConcurrentDials := uint(flags.Get().MaxConcurrentDials)
-				missingPeerCount = min(missingPeerCount, maxConcurrentDials)
-			}
-
-			// Search for new peers.
-			wantedNodes := searchForPeers(iterator, batchPeriod, missingPeerCount, s.filterPeer)
-
-			wg := new(sync.WaitGroup)
-			for i := 0; i < len(wantedNodes); i++ {
-				node := wantedNodes[i]
-				peerInfo, _, err := convertToAddrInfo(node)
-				if err != nil {
-					log.WithError(err).Error("Could not convert to peer info")
-					continue
+				if err := s.findAndDialPeers(ctx); err != nil && !errors.Is(err, context.DeadlineExceeded) {
+					log.WithError(err).Error("Failed to find and dial peers")
 				}
-
-				if peerInfo == nil {
-					continue
-				}
-
-				// Make sure that peer is not dialed too often, for each connection attempt there's a backoff period.
-				s.Peers().RandomizeBackOff(peerInfo.ID)
-				wg.Add(1)
-				go func(info *peer.AddrInfo) {
-					if err := s.connectWithPeer(s.ctx, *info); err != nil {
-						log.WithError(err).Tracef("Could not connect with peer %s", info.String())
-					}
-					wg.Done()
-				}(peerInfo)
-			}
-			wg.Wait()
+			}()
 		}
 	}
 }
 
+// FindAndDialPeersWithSubnets ensures that our node is connected to enough peers.
+// If, the threshold is met, then this function immediately returns.
+// Otherwise, it searches for new peers and dials them.
+// If `ctx“ is canceled while searching for peers, search is stopped, but new found peers are still dialed.
+// In this case, the function returns an error.
+func (s *Service) findAndDialPeers(ctx context.Context) error {
+	// Restrict dials if limit is applied.
+	maxConcurrentDials := math.MaxInt
+	if flags.MaxDialIsActive() {
+		maxConcurrentDials = flags.Get().MaxConcurrentDials
+	}
+
+	missingPeerCount := s.missingPeerCount(s.cfg.MaxPeers)
+	for missingPeerCount > 0 {
+		// Stop the search/dialing loop if the context is canceled.
+		if err := ctx.Err(); err != nil {
+			return err
+		}
+
+		peersToDial, err := func() ([]*enode.Node, error) {
+			ctx, cancel := context.WithTimeout(ctx, batchPeriod)
+			defer cancel()
+
+			peersToDial, err := s.findPeers(ctx, missingPeerCount)
+			if err != nil && !errors.Is(err, context.DeadlineExceeded) {
+				return nil, errors.Wrap(err, "find peers")
+			}
+
+			return peersToDial, nil
+		}()
+
+		if err != nil {
+			return err
+		}
+
+		dialedPeerCount := s.dialPeers(s.ctx, maxConcurrentDials, peersToDial)
+
+		if dialedPeerCount > missingPeerCount {
+			missingPeerCount = 0
+			continue
+		}
+
+		missingPeerCount -= dialedPeerCount
+	}
+
+	return nil
+}
+
+// findAndDialPeers finds new peers until `targetPeerCount` is reached, `batchPeriod` is over,
+// the peers iterator is exhausted or the context is canceled.
+func (s *Service) findPeers(ctx context.Context, missingPeerCount uint) ([]*enode.Node, error) {
+	// Create an discovery iterator to find new peers.
+	iterator := s.dv5Listener.RandomNodes()
+
+	// `iterator.Next` can block indefinitely. `iterator.Close` unblocks it.
+	// So it is important to close the iterator when the context is done to ensure
+	// that the search does not hang indefinitely.
+	go func() {
+		<-ctx.Done()
+		iterator.Close()
+	}()
+
+	// Crawl the network for peers subscribed to the defective subnets.
+	nodeByNodeID := make(map[enode.ID]*enode.Node)
+	for missingPeerCount > 0 && iterator.Next() {
+		if ctx.Err() != nil {
+			peersToDial := make([]*enode.Node, 0, len(nodeByNodeID))
+			for _, node := range nodeByNodeID {
+				peersToDial = append(peersToDial, node)
+			}
+
+			return peersToDial, ctx.Err()
+		}
+
+		// Skip peer not matching the filter.
+		node := iterator.Node()
+		if !s.filterPeer(node) {
+			continue
+		}
+
+		// Remove duplicates, keeping the node with higher seq.
+		existing, ok := nodeByNodeID[node.ID()]
+		if ok && existing.Seq() > node.Seq() {
+			continue
+		}
+		nodeByNodeID[node.ID()] = node
+
+		// We found a new peer. Decrease the missing peer count.
+		missingPeerCount--
+	}
+
+	// Convert the map to a slice.
+	peersToDial := make([]*enode.Node, 0, len(nodeByNodeID))
+	for _, node := range nodeByNodeID {
+		peersToDial = append(peersToDial, node)
+	}
+
+	return peersToDial, nil
+}
+
+// missingPeerCount computes how many peers we are missing to reach the target peer count.
+func (s *Service) missingPeerCount(targetCount uint) uint {
+	// Retrieve how many active peers we have.
+	activePeers := s.Peers().Active()
+	activePeerCount := uint(len(activePeers))
+
+	// Compute how many peers we are missing to reach the threshold.
+	missingPeerCount := uint(0)
+	if targetCount > activePeerCount {
+		missingPeerCount = targetCount - activePeerCount
+	}
+
+	return missingPeerCount
+}
+
 func (s *Service) createListener(
 	ipAddr net.IP,
 	privKey *ecdsa.PrivateKey,
@@ -476,7 +545,7 @@ func (s *Service) createLocalNode(
 	ipAddr net.IP,
 	udpPort, tcpPort, quicPort int,
 ) (*enode.LocalNode, error) {
-	db, err := enode.OpenDB("")
+	db, err := enode.OpenDB(s.cfg.DiscoveryDir)
 	if err != nil {
 		return nil, errors.Wrap(err, "could not open node's peer database")
 	}
@@ -535,7 +604,10 @@ func (s *Service) createLocalNode(
 			localNode.SetFallbackIP(firstIP)
 		}
 	}
-
+	log.WithFields(logrus.Fields{
+		"seq": localNode.Seq(),
+		"id":  localNode.ID(),
+	}).Debug("Local node created")
 	return localNode, nil
 }
 
@@ -551,7 +623,11 @@ func (s *Service) startDiscoveryV5(
 		return nil, errors.Wrap(err, "could not create listener")
 	}
 	record := wrappedListener.Self()
-	log.WithField("ENR", record.String()).Info("Started discovery v5")
+
+	log.WithFields(logrus.Fields{
+		"ENR": record.String(),
+		"seq": record.Seq(),
+	}).Info("Started discovery v5")
 	return wrappedListener, nil
 }
 
@@ -562,8 +638,7 @@ func (s *Service) startDiscoveryV5(
 //  2. Peer hasn't been marked as 'bad'.
 //  3. Peer is not currently active or connected.
 //  4. Peer is ready to receive incoming connections.
-//  5. Peer's fork digest in their ENR matches that of
-//     our localnodes.
+//  5. Peer's fork digest in their ENR matches that of our localnodes.
 func (s *Service) filterPeer(node *enode.Node) bool {
 	// Ignore nil node entries passed in.
 	if node == nil {
@@ -628,22 +703,24 @@ func (s *Service) filterPeer(node *enode.Node) bool {
 // This checks our set max peers in our config, and
 // determines whether our currently connected and
 // active peers are above our set max peer limit.
-func (s *Service) isPeerAtLimit(inbound bool) bool {
-	numOfConns := len(s.host.Network().Peers())
+func (s *Service) isPeerAtLimit(direction connectivityDirection) bool {
 	maxPeers := int(s.cfg.MaxPeers)
-	// If we are measuring the limit for inbound peers
-	// we apply the high watermark buffer.
-	if inbound {
+
+	// If we are measuring the limit for inbound peers we apply the high watermark buffer.
+	if direction == inbound {
 		maxPeers += highWatermarkBuffer
 		maxInbound := s.peers.InboundLimit() + highWatermarkBuffer
-		currInbound := len(s.peers.InboundConnected())
-		// Exit early if we are at the inbound limit.
-		if currInbound >= maxInbound {
+		inboundCount := len(s.peers.InboundConnected())
+
+		// Return early if we are at the inbound limit.
+		if inboundCount >= maxInbound {
 			return true
 		}
 	}
-	activePeers := len(s.Peers().Active())
-	return activePeers >= maxPeers || numOfConns >= maxPeers
+
+	peerCount := len(s.host.Network().Peers())
+	activePeerCount := len(s.Peers().Active())
+	return activePeerCount >= maxPeers || peerCount >= maxPeers
 }
 
 // isBelowOutboundPeerThreshold checks if the number of outbound peers that
@@ -901,7 +978,7 @@ func multiAddrFromString(address string) (ma.Multiaddr, error) {
 	return ma.NewMultiaddr(address)
 }
 
-func udpVersionFromIP(ipAddr net.IP) int {
+func udpVersionFromIP(ipAddr net.IP) udpVersion {
 	if ipAddr.To4() != nil {
 		return udp4
 	}

beacon-chain/p2p/discovery_test.go

@@ -264,6 +264,7 @@ func TestRebootDiscoveryListener(t *testing.T) {
 		genesisValidatorsRoot: bytesutil.PadTo([]byte{'A'}, 32),
 		cfg:                   &Config{UDPPort: uint(port)},
 	}
+
 	createListener := func() (*discover.UDPv5, error) {
 		return s.createListener(ipAddr, pkey)
 	}
@@ -293,6 +294,7 @@ func TestMultiAddrsConversion_InvalidIPAddr(t *testing.T) {
 	s := &Service{
 		genesisTime:           time.Now(),
 		genesisValidatorsRoot: bytesutil.PadTo([]byte{'A'}, 32),
+		cfg:                   &Config{},
 	}
 	node, err := s.createLocalNode(pkey, addr, 0, 0, 0)
 	require.NoError(t, err)
@@ -323,16 +325,16 @@ func TestMultiAddrConversion_OK(t *testing.T) {
 }
 
 func TestStaticPeering_PeersAreAdded(t *testing.T) {
+	const port = uint(6000)
 	cs := startup.NewClockSynchronizer()
 	cfg := &Config{
 		MaxPeers:    30,
 		ClockWaiter: cs,
 	}
-	port := 6000
 	var staticPeers []string
 	var hosts []host.Host
 	// setup other nodes
-	for i := 1; i <= 5; i++ {
+	for i := uint(1); i <= 5; i++ {
 		h, _, ipaddr := createHost(t, port+i)
 		staticPeers = append(staticPeers, fmt.Sprintf("/ip4/%s/tcp/%d/p2p/%s", ipaddr, port+i, h.ID()))
 		hosts = append(hosts, h)
@@ -370,14 +372,17 @@ func TestStaticPeering_PeersAreAdded(t *testing.T) {
 }
 
 func TestHostIsResolved(t *testing.T) {
-	// ip.addr.tools - construct domain names that resolve to any given IP address
-	// ex: 192-0-2-1.ip.addr.tools resolves to 192.0.2.1.
-	exampleHost := "96-7-129-13.ip.addr.tools"
-	exampleIP := "96.7.129.13"
+	host := "dns.google"
+	ips := map[string]bool{
+		"8.8.8.8":              true,
+		"8.8.4.4":              true,
+		"2001:4860:4860::8888": true,
+		"2001:4860:4860::8844": true,
+	}
 
 	s := &Service{
 		cfg: &Config{
-			HostDNS: exampleHost,
+			HostDNS: host,
 		},
 		genesisTime:           time.Now(),
 		genesisValidatorsRoot: bytesutil.PadTo([]byte{'A'}, 32),
@@ -387,7 +392,7 @@ func TestHostIsResolved(t *testing.T) {
 	require.NoError(t, err)
 
 	newIP := list.Self().IP()
-	assert.Equal(t, exampleIP, newIP.String(), "Did not resolve to expected IP")
+	assert.Equal(t, true, ips[newIP.String()], "Did not resolve to expected IP")
 }
 
 func TestInboundPeerLimit(t *testing.T) {
@@ -406,14 +411,14 @@ func TestInboundPeerLimit(t *testing.T) {
 		_ = addPeer(t, s.peers, peerdata.ConnectionState(ethpb.ConnectionState_CONNECTED), false)
 	}
 
-	require.Equal(t, true, s.isPeerAtLimit(false), "not at limit for outbound peers")
-	require.Equal(t, false, s.isPeerAtLimit(true), "at limit for inbound peers")
+	require.Equal(t, true, s.isPeerAtLimit(all), "not at limit for outbound peers")
+	require.Equal(t, false, s.isPeerAtLimit(inbound), "at limit for inbound peers")
 
 	for i := 0; i < highWatermarkBuffer; i++ {
 		_ = addPeer(t, s.peers, peerdata.ConnectionState(ethpb.ConnectionState_CONNECTED), false)
 	}
 
-	require.Equal(t, true, s.isPeerAtLimit(true), "not at limit for inbound peers")
+	require.Equal(t, true, s.isPeerAtLimit(inbound), "not at limit for inbound peers")
 }
 
 func TestOutboundPeerThreshold(t *testing.T) {
@@ -492,6 +497,35 @@ func TestMultipleDiscoveryAddresses(t *testing.T) {
 	assert.Equal(t, true, ipv6Found, "IPv6 discovery address not found")
 }
 
+func TestDiscoveryV5_SeqNumber(t *testing.T) {
+	db, err := enode.OpenDB(t.TempDir())
+	require.NoError(t, err)
+	_, key := createAddrAndPrivKey(t)
+	node := enode.NewLocalNode(db, key)
+	node.Set(enr.IPv4{127, 0, 0, 1})
+	currentSeq := node.Seq()
+	s := &Service{dv5Listener: mockListener{localNode: node}}
+	_, err = s.DiscoveryAddresses()
+	require.NoError(t, err)
+	newSeq := node.Seq()
+	require.Equal(t, currentSeq+1, newSeq) // node seq should increase when discovery starts
+
+	// see that the keys changing, will change the node seq
+	_, keyTwo := createAddrAndPrivKey(t)
+	nodeTwo := enode.NewLocalNode(db, keyTwo) // use the same db with different key
+	nodeTwo.Set(enr.IPv6{0x20, 0x01, 0x48, 0x60, 0, 0, 0x20, 0x01, 0, 0, 0, 0, 0, 0, 0x00, 0x68})
+	seqTwo := nodeTwo.Seq()
+	assert.NotEqual(t, seqTwo, newSeq)
+	sTwo := &Service{dv5Listener: mockListener{localNode: nodeTwo}}
+	_, err = sTwo.DiscoveryAddresses()
+	require.NoError(t, err)
+	assert.Equal(t, seqTwo+1, nodeTwo.Seq())
+
+	// see that reloading the same node with same key and db results in same seq number
+	nodeThree := enode.NewLocalNode(db, key)
+	assert.Equal(t, node.Seq(), nodeThree.Seq())
+}
+
 func TestCorrectUDPVersion(t *testing.T) {
 	assert.Equal(t, udp4, udpVersionFromIP(net.IPv4zero), "incorrect network version")
 	assert.Equal(t, udp6, udpVersionFromIP(net.IPv6zero), "incorrect network version")

beacon-chain/p2p/doc.go

@@ -1,7 +1,7 @@
 /*
 Package p2p implements the Ethereum consensus networking specification.
 
-Canonical spec reference: https://github.com/ethereum/consensus-specs/blob/dev/specs/phase0/p2p-interface.md
+Canonical spec reference: https://github.com/ethereum/consensus-specs/blob/master/specs/phase0/p2p-interface.md
 
 Prysm specific implementation design docs
   - Networking Design Doc: https://docs.google.com/document/d/1VyhobQRkEjEkEPxmmdWvaHfKWn0j6dEae_wLZlrFtfU/view

beacon-chain/p2p/handshake.go

@@ -10,13 +10,17 @@ import (
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/peers"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/peers/peerdata"
 	prysmTime "github.com/OffchainLabs/prysm/v6/time"
+	"github.com/libp2p/go-libp2p/core/host"
 	"github.com/libp2p/go-libp2p/core/network"
 	"github.com/libp2p/go-libp2p/core/peer"
+	"github.com/patrickmn/go-cache"
 	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
 )
 
 const (
+	agentVersionKey = "AgentVersion"
+
 	// The time to wait for a status request.
 	timeForStatus = 10 * time.Second
 )
@@ -28,12 +32,15 @@ func peerMultiaddrString(conn network.Conn) string {
 }
 
 func (s *Service) connectToPeer(conn network.Conn) {
-	s.peers.SetConnectionState(conn.RemotePeer(), peers.Connected)
+	remotePeer := conn.RemotePeer()
+
+	s.peers.SetConnectionState(remotePeer, peers.Connected)
 	// Go through the handshake process.
 	log.WithFields(logrus.Fields{
 		"direction":   conn.Stat().Direction.String(),
 		"multiAddr":   peerMultiaddrString(conn),
 		"activePeers": len(s.peers.Active()),
+		"agent":       agentString(remotePeer, s.Host()),
 	}).Debug("Initiate peer connection")
 }
 
@@ -61,6 +68,7 @@ func (s *Service) disconnectFromPeerOnError(
 			"multiaddr":            peerMultiaddrString(conn),
 			"direction":            conn.Stat().Direction.String(),
 			"remainingActivePeers": len(s.peers.Active()),
+			"agent":                agentString(remotePeerID, s.Host()),
 		}).
 		Debug("Initiate peer disconnection")
 
@@ -72,8 +80,8 @@ func (s *Service) disconnectFromPeerOnError(
 // and validating the response from the peer.
 func (s *Service) AddConnectionHandler(reqFunc, goodByeFunc func(ctx context.Context, id peer.ID) error) {
 	// Peer map and lock to keep track of current connection attempts.
+	var peerLock sync.Mutex
 	peerMap := make(map[peer.ID]bool)
-	peerLock := new(sync.Mutex)
 
 	// This is run at the start of each connection attempt, to ensure
 	// that there aren't multiple inflight connection requests for the
@@ -101,6 +109,19 @@ func (s *Service) AddConnectionHandler(reqFunc, goodByeFunc func(ctx context.Con
 	s.host.Network().Notify(&network.NotifyBundle{
 		ConnectedF: func(_ network.Network, conn network.Conn) {
 			remotePeer := conn.RemotePeer()
+			log := log.WithField("peer", remotePeer)
+			direction := conn.Stat().Direction
+
+			// For some reason, right after a disconnection, this `ConnectedF` callback
+			// is called. We want to avoid processing this connection if the peer was
+			// disconnected too recently and if we are at the initiative of this connection.
+			// This is very probably a bug in libp2p.
+			if direction == network.DirOutbound {
+				if err := s.wasDisconnectedTooRecently(remotePeer); err != nil {
+					log.WithError(err).Debug("Skipping connection handler")
+					return
+				}
+			}
 
 			// Connection handler must be non-blocking as part of libp2p design.
 			go func() {
@@ -126,53 +147,56 @@ func (s *Service) AddConnectionHandler(reqFunc, goodByeFunc func(ctx context.Con
 					return
 				}
 
-				// Do not perform handshake on inbound dials.
-				if conn.Stat().Direction == network.DirInbound {
-					_, err := s.peers.ChainState(remotePeer)
-					peerExists := err == nil
-					currentTime := prysmTime.Now()
-
-					// Wait for peer to initiate handshake
-					time.Sleep(timeForStatus)
-
-					// Exit if we are disconnected with the peer.
-					if s.host.Network().Connectedness(remotePeer) != network.Connected {
+				if direction != network.DirInbound {
+					s.peers.SetConnectionState(conn.RemotePeer(), peers.Connecting)
+					if err := reqFunc(context.TODO(), conn.RemotePeer()); err != nil && !errors.Is(err, io.EOF) {
+						s.disconnectFromPeerOnError(conn, goodByeFunc, err)
 						return
 					}
 
-					// If peer hasn't sent a status request, we disconnect with them
-					if _, err := s.peers.ChainState(remotePeer); errors.Is(err, peerdata.ErrPeerUnknown) || errors.Is(err, peerdata.ErrNoPeerStatus) {
-						statusMessageMissing.Inc()
-						s.disconnectFromPeerOnError(conn, goodByeFunc, errors.Wrap(err, "chain state"))
-						return
-					}
-
-					if peerExists {
-						updated, err := s.peers.ChainStateLastUpdated(remotePeer)
-						if err != nil {
-							s.disconnectFromPeerOnError(conn, goodByeFunc, errors.Wrap(err, "chain state last updated"))
-							return
-						}
-
-						// Exit if we don't receive any current status messages from peer.
-						if updated.IsZero() {
-							s.disconnectFromPeerOnError(conn, goodByeFunc, errors.New("is zero"))
-							return
-						}
-
-						if updated.Before(currentTime) {
-							s.disconnectFromPeerOnError(conn, goodByeFunc, errors.New("did not update"))
-							return
-						}
-					}
-
 					s.connectToPeer(conn)
 					return
 				}
 
-				s.peers.SetConnectionState(conn.RemotePeer(), peers.Connecting)
-				if err := reqFunc(context.TODO(), conn.RemotePeer()); err != nil && !errors.Is(err, io.EOF) {
-					s.disconnectFromPeerOnError(conn, goodByeFunc, err)
+				// The connection is inbound.
+				_, err = s.peers.ChainState(remotePeer)
+				peerExists := err == nil
+				currentTime := prysmTime.Now()
+
+				// Wait for peer to initiate handshake
+				time.Sleep(timeForStatus)
+
+				// Exit if we are disconnected with the peer.
+				if s.host.Network().Connectedness(remotePeer) != network.Connected {
+					return
+				}
+
+				// If peer hasn't sent a status request, we disconnect with them
+				if _, err := s.peers.ChainState(remotePeer); errors.Is(err, peerdata.ErrPeerUnknown) || errors.Is(err, peerdata.ErrNoPeerStatus) {
+					statusMessageMissing.Inc()
+					s.disconnectFromPeerOnError(conn, goodByeFunc, errors.Wrap(err, "chain state"))
+					return
+				}
+
+				if !peerExists {
+					s.connectToPeer(conn)
+					return
+				}
+
+				updated, err := s.peers.ChainStateLastUpdated(remotePeer)
+				if err != nil {
+					s.disconnectFromPeerOnError(conn, goodByeFunc, errors.Wrap(err, "chain state last updated"))
+					return
+				}
+
+				// Exit if we don't receive any current status messages from peer.
+				if updated.IsZero() {
+					s.disconnectFromPeerOnError(conn, goodByeFunc, errors.New("is zero"))
+					return
+				}
+
+				if updated.Before(currentTime) {
+					s.disconnectFromPeerOnError(conn, goodByeFunc, errors.New("did not update"))
 					return
 				}
 
@@ -189,9 +213,10 @@ func (s *Service) AddDisconnectionHandler(handler func(ctx context.Context, id p
 		DisconnectedF: func(net network.Network, conn network.Conn) {
 			peerID := conn.RemotePeer()
 
-			log.WithFields(logrus.Fields{
+			log := log.WithFields(logrus.Fields{
 				"multiAddr": peerMultiaddrString(conn),
 				"direction": conn.Stat().Direction.String(),
+				"agent":     agentString(peerID, s.Host()),
 			})
 			// Must be handled in a goroutine as this callback cannot be blocking.
 			go func() {
@@ -212,6 +237,12 @@ func (s *Service) AddDisconnectionHandler(handler func(ctx context.Context, id p
 				}
 
 				s.peers.SetConnectionState(peerID, peers.Disconnected)
+				if err := s.peerDisconnectionTime.Add(peerID.String(), time.Now(), cache.DefaultExpiration); err != nil {
+					// The `DisconnectedF` funcition already called for this peer less than `cache.DefaultExpiration` ago. Skip.
+					// (Very probably a bug in libp2p.)
+					log.WithError(err).Trace("Failed to set peer disconnection time")
+					return
+				}
 
 				// Only log disconnections if we were fully connected.
 				if priorState == peers.Connected {
@@ -222,3 +253,36 @@ func (s *Service) AddDisconnectionHandler(handler func(ctx context.Context, id p
 		},
 	})
 }
+
+// wasDisconnectedTooRecently checks if the peer was disconnected within the last second.
+func (s *Service) wasDisconnectedTooRecently(peerID peer.ID) error {
+	const disconnectionDurationThreshold = 1 * time.Second
+
+	peerDisconnectionTimeObj, ok := s.peerDisconnectionTime.Get(peerID.String())
+	if !ok {
+		return nil
+	}
+
+	peerDisconnectionTime, ok := peerDisconnectionTimeObj.(time.Time)
+	if !ok {
+		return errors.New("invalid peer disconnection time type")
+	}
+
+	timeSinceDisconnection := time.Since(peerDisconnectionTime)
+	if timeSinceDisconnection < disconnectionDurationThreshold {
+		return errors.Errorf("peer %s was disconnected too recently: %s", peerID, timeSinceDisconnection)
+	}
+
+	return nil
+}
+
+func agentString(pid peer.ID, hst host.Host) string {
+	rawVersion, storeErr := hst.Peerstore().Get(pid, agentVersionKey)
+
+	result, ok := rawVersion.(string)
+	if storeErr != nil || !ok {
+		result = ""
+	}
+
+	return result
+}

beacon-chain/p2p/interfaces.go

@@ -49,7 +49,7 @@ type (
 		BroadcastBlob(ctx context.Context, subnet uint64, blob *ethpb.BlobSidecar) error
 		BroadcastLightClientOptimisticUpdate(ctx context.Context, update interfaces.LightClientOptimisticUpdate) error
 		BroadcastLightClientFinalityUpdate(ctx context.Context, update interfaces.LightClientFinalityUpdate) error
-		BroadcastDataColumn(root [fieldparams.RootLength]byte, columnSubnet uint64, dataColumnSidecar *ethpb.DataColumnSidecar, peersChecked ...chan<- bool) error
+		BroadcastDataColumn(root [fieldparams.RootLength]byte, columnSubnet uint64, dataColumnSidecar *ethpb.DataColumnSidecar) error
 	}
 
 	// SetStreamHandler configures p2p to handle streams of a certain topic ID.
@@ -98,7 +98,7 @@ type (
 		NodeID() enode.ID
 		DiscoveryAddresses() ([]multiaddr.Multiaddr, error)
 		RefreshPersistentSubnets()
-		FindPeersWithSubnet(ctx context.Context, topic string, subIndex uint64, threshold int) (bool, error)
+		FindAndDialPeersWithSubnets(ctx context.Context, topicFormat string, digest [fieldparams.VersionLength]byte, minimumPeersPerSubnet int, subnets map[uint64]bool) error
 		AddPingMethod(reqFunc func(ctx context.Context, id peer.ID) error)
 	}
 

beacon-chain/p2p/peers/scorers/bad_responses.go

@@ -101,21 +101,24 @@ func (s *BadResponsesScorer) countNoLock(pid peer.ID) (int, error) {
 
 // Increment increments the number of bad responses we have received from the given remote peer.
 // If peer doesn't exist this method is no-op.
-func (s *BadResponsesScorer) Increment(pid peer.ID) {
+func (s *BadResponsesScorer) Increment(pid peer.ID) int {
 	if pid == "" {
-		return
+		return 0
 	}
+
 	s.store.Lock()
 	defer s.store.Unlock()
 
 	peerData, ok := s.store.PeerData(pid)
-	if !ok {
-		s.store.SetPeerData(pid, &peerdata.PeerData{
-			BadResponses: 1,
-		})
-		return
+	if ok {
+		peerData.BadResponses++
+		return peerData.BadResponses
 	}
-	peerData.BadResponses++
+
+	const badResponses = 1
+	peerData = &peerdata.PeerData{BadResponses: badResponses}
+	s.store.SetPeerData(pid, peerData)
+	return badResponses
 }
 
 // IsBadPeer states if the peer is to be considered bad.

beacon-chain/p2p/peers/status.go

@@ -393,7 +393,7 @@ func (p *Status) SetNextValidTime(pid peer.ID, nextTime time.Time) {
 	peerData.NextValidTime = nextTime
 }
 
-// RandomizeBackOff adds extra backoff period during which peer will not be dialed.
+// RandomizeBackOff adds extra backoff period during which peer won't be dialed.
 func (p *Status) RandomizeBackOff(pid peer.ID) {
 	p.store.Lock()
 	defer p.store.Unlock()

beacon-chain/p2p/service.go

@@ -31,30 +31,35 @@ import (
 	"github.com/libp2p/go-libp2p/core/peer"
 	"github.com/libp2p/go-libp2p/core/protocol"
 	"github.com/multiformats/go-multiaddr"
+	"github.com/patrickmn/go-cache"
 	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
 )
 
 var _ runtime.Service = (*Service)(nil)
 
-// In the event that we are at our peer limit, we
-// stop looking for new peers and instead poll
-// for the current peer limit status for the time period
-// defined below.
-var pollingPeriod = 6 * time.Second
+const (
+	// When looking for new nodes, if not enough nodes are found,
+	// we stop after this spent time.
+	batchPeriod = 2 * time.Second
 
-// When looking for new nodes, if not enough nodes are found,
-// we stop after this spent time.
-var batchPeriod = 2 * time.Second
+	// maxBadResponses is the maximum number of bad responses from a peer before we stop talking to it.
+	maxBadResponses = 5
+)
 
-// Refresh rate of ENR set at twice per slot.
-var refreshRate = slots.DivideSlotBy(2)
+var (
+	// Refresh rate of ENR set at twice per slot.
+	refreshRate = slots.DivideSlotBy(2)
 
-// maxBadResponses is the maximum number of bad responses from a peer before we stop talking to it.
-const maxBadResponses = 5
+	// maxDialTimeout is the timeout for a single peer dial.
+	maxDialTimeout = params.BeaconConfig().RespTimeoutDuration()
 
-// maxDialTimeout is the timeout for a single peer dial.
-var maxDialTimeout = params.BeaconConfig().RespTimeoutDuration()
+	// In the event that we are at our peer limit, we
+	// stop looking for new peers and instead poll
+	// for the current peer limit status for the time period
+	// defined below.
+	pollingPeriod = 6 * time.Second
+)
 
 // Service for managing peer to peer (p2p) networking.
 type Service struct {
@@ -82,6 +87,7 @@ type Service struct {
 	genesisTime           time.Time
 	genesisValidatorsRoot []byte
 	activeValidatorCount  uint64
+	peerDisconnectionTime *cache.Cache
 }
 
 // NewService initializes a new p2p service compatible with shared.Service interface. No
@@ -111,16 +117,17 @@ func NewService(ctx context.Context, cfg *Config) (*Service, error) {
 	ipLimiter := leakybucket.NewCollector(ipLimit, ipBurst, 30*time.Second, true /* deleteEmptyBuckets */)
 
 	s := &Service{
-		ctx:          ctx,
-		cancel:       cancel,
-		cfg:          cfg,
-		addrFilter:   addrFilter,
-		ipLimiter:    ipLimiter,
-		privKey:      privKey,
-		metaData:     metaData,
-		isPreGenesis: true,
-		joinedTopics: make(map[string]*pubsub.Topic, len(gossipTopicMappings)),
-		subnetsLock:  make(map[uint64]*sync.RWMutex),
+		ctx:                   ctx,
+		cancel:                cancel,
+		cfg:                   cfg,
+		addrFilter:            addrFilter,
+		ipLimiter:             ipLimiter,
+		privKey:               privKey,
+		metaData:              metaData,
+		isPreGenesis:          true,
+		joinedTopics:          make(map[string]*pubsub.Topic, len(gossipTopicMappings)),
+		subnetsLock:           make(map[uint64]*sync.RWMutex),
+		peerDisconnectionTime: cache.New(1*time.Second, 1*time.Minute),
 	}
 
 	ipAddr := prysmnetwork.IPAddr()
@@ -251,6 +258,7 @@ func (s *Service) Start() {
 			"inboundTCP":  inboundTCPCount,
 			"outboundTCP": outboundTCPCount,
 			"total":       total,
+			"target":      s.cfg.MaxPeers,
 		}
 
 		if features.Get().EnableQUIC {
@@ -403,7 +411,10 @@ func (s *Service) pingPeersAndLogEnr() {
 	defer s.pingMethodLock.RUnlock()
 
 	localENR := s.dv5Listener.Self()
-	log.WithField("ENR", localENR).Info("New node record")
+	log.WithFields(logrus.Fields{
+		"ENR": localENR,
+		"seq": localENR.Seq(),
+	}).Info("New node record")
 
 	if s.pingMethod == nil {
 		return
@@ -481,14 +492,17 @@ func (s *Service) connectWithPeer(ctx context.Context, info peer.AddrInfo) error
 	if info.ID == s.host.ID() {
 		return nil
 	}
+
 	if err := s.Peers().IsBad(info.ID); err != nil {
-		return errors.Wrap(err, "refused to connect to bad peer")
+		return errors.Wrap(err, "bad peer")
 	}
+
 	ctx, cancel := context.WithTimeout(ctx, maxDialTimeout)
 	defer cancel()
+
 	if err := s.host.Connect(ctx, info); err != nil {
-		s.Peers().Scorers().BadResponsesScorer().Increment(info.ID)
-		return err
+		s.downscorePeer(info.ID, "connectionError")
+		return errors.Wrap(err, "peer connect")
 	}
 	return nil
 }
@@ -519,3 +533,8 @@ func (s *Service) connectToBootnodes() error {
 func (s *Service) isInitialized() bool {
 	return !s.genesisTime.IsZero() && len(s.genesisValidatorsRoot) == 32
 }
+
+func (s *Service) downscorePeer(peerID peer.ID, reason string) {
+	newScore := s.Peers().Scorers().BadResponsesScorer().Increment(peerID)
+	log.WithFields(logrus.Fields{"peerID": peerID, "reason": reason, "newScore": newScore}).Debug("Downscore peer")
+}

beacon-chain/p2p/service_test.go

@@ -13,6 +13,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/peers"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/peers/scorers"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/startup"
+	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
 	"github.com/OffchainLabs/prysm/v6/config/params"
 	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
 	"github.com/OffchainLabs/prysm/v6/network/forks"
@@ -72,7 +73,7 @@ func (mockListener) RandomNodes() enode.Iterator {
 
 func (mockListener) RebootListener() error { panic("implement me") }
 
-func createHost(t *testing.T, port int) (host.Host, *ecdsa.PrivateKey, net.IP) {
+func createHost(t *testing.T, port uint) (host.Host, *ecdsa.PrivateKey, net.IP) {
 	_, pkey := createAddrAndPrivKey(t)
 	ipAddr := net.ParseIP("127.0.0.1")
 	listen, err := multiaddr.NewMultiaddr(fmt.Sprintf("/ip4/%s/tcp/%d", ipAddr, port))
@@ -185,21 +186,33 @@ func TestService_Start_NoDiscoverFlag(t *testing.T) {
 }
 
 func TestListenForNewNodes(t *testing.T) {
+	const (
+		port              = uint(2000)
+		testPollingPeriod = 1 * time.Second
+		peerCount         = 5
+	)
+
 	params.SetupTestConfigCleanup(t)
+
 	// Setup bootnode.
-	notifier := &mock.MockStateNotifier{}
-	cfg := &Config{StateNotifier: notifier, PingInterval: testPingInterval, DisableLivenessCheck: true}
-	port := 2000
-	cfg.UDPPort = uint(port)
+	cfg := &Config{
+		StateNotifier:        &mock.MockStateNotifier{},
+		PingInterval:         testPingInterval,
+		DisableLivenessCheck: true,
+		UDPPort:              port,
+	}
+
 	_, pkey := createAddrAndPrivKey(t)
 	ipAddr := net.ParseIP("127.0.0.1")
 	genesisTime := prysmTime.Now()
-	var gvr [32]byte
+	var gvr [fieldparams.RootLength]byte
+
 	s := &Service{
 		cfg:                   cfg,
 		genesisTime:           genesisTime,
 		genesisValidatorsRoot: gvr[:],
 	}
+
 	bootListener, err := s.createListener(ipAddr, pkey)
 	require.NoError(t, err)
 	defer bootListener.Close()
@@ -210,35 +223,40 @@ func TestListenForNewNodes(t *testing.T) {
 
 	// Use shorter period for testing.
 	currentPeriod := pollingPeriod
-	pollingPeriod = 1 * time.Second
+	pollingPeriod = testPollingPeriod
 	defer func() {
 		pollingPeriod = currentPeriod
 	}()
 
 	bootNode := bootListener.Self()
 
-	var listeners []*listenerWrapper
-	var hosts []host.Host
-	// setup other nodes.
+	// Setup other nodes.
 	cs := startup.NewClockSynchronizer()
-	cfg = &Config{
-		Discv5BootStrapAddrs: []string{bootNode.String()},
-		PingInterval:         testPingInterval,
-		DisableLivenessCheck: true,
-		MaxPeers:             30,
-		ClockWaiter:          cs,
-	}
-	for i := 1; i <= 5; i++ {
+	listeners := make([]*listenerWrapper, 0, peerCount)
+	hosts := make([]host.Host, 0, peerCount)
+
+	for i := uint(1); i <= peerCount; i++ {
+		cfg = &Config{
+			Discv5BootStrapAddrs: []string{bootNode.String()},
+			PingInterval:         testPingInterval,
+			DisableLivenessCheck: true,
+			MaxPeers:             peerCount,
+			ClockWaiter:          cs,
+			UDPPort:              port + i,
+			TCPPort:              port + i,
+		}
+
 		h, pkey, ipAddr := createHost(t, port+i)
-		cfg.UDPPort = uint(port + i)
-		cfg.TCPPort = uint(port + i)
+
 		s := &Service{
 			cfg:                   cfg,
 			genesisTime:           genesisTime,
 			genesisValidatorsRoot: gvr[:],
 		}
+
 		listener, err := s.startDiscoveryV5(ipAddr, pkey)
-		assert.NoError(t, err, "Could not start discovery for node")
+		require.NoError(t, err, "Could not start discovery for node")
+
 		listeners = append(listeners, listener)
 		hosts = append(hosts, h)
 	}
@@ -263,19 +281,26 @@ func TestListenForNewNodes(t *testing.T) {
 
 	s, err = NewService(t.Context(), cfg)
 	require.NoError(t, err)
-	exitRoutine := make(chan bool)
-	go func() {
-		s.Start()
-		<-exitRoutine
-	}()
-	time.Sleep(1 * time.Second)
 
-	require.NoError(t, cs.SetClock(startup.NewClock(genesisTime, gvr)))
+	go s.Start()
 
-	time.Sleep(4 * time.Second)
-	assert.Equal(t, 5, len(s.host.Network().Peers()), "Not all peers added to peerstore")
-	require.NoError(t, s.Stop())
-	exitRoutine <- true
+	err = cs.SetClock(startup.NewClock(genesisTime, gvr))
+	require.NoError(t, err, "Could not set clock in service")
+
+	actualPeerCount := len(s.host.Network().Peers())
+	for range 40 {
+		if actualPeerCount == peerCount {
+			break
+		}
+
+		time.Sleep(100 * time.Millisecond)
+		actualPeerCount = len(s.host.Network().Peers())
+	}
+
+	assert.Equal(t, peerCount, actualPeerCount, "Not all peers added to peerstore")
+
+	err = s.Stop()
+	require.NoError(t, err, "Failed to stop service")
 }
 
 func TestPeer_Disconnect(t *testing.T) {
@@ -378,7 +403,7 @@ func TestService_connectWithPeer(t *testing.T) {
 				return ps
 			}(),
 			info:    peer.AddrInfo{ID: "bad"},
-			wantErr: "refused to connect to bad peer",
+			wantErr: "bad peer",
 		},
 	}
 	for _, tt := range tests {

beacon-chain/p2p/subnets.go

@@ -2,6 +2,7 @@ package p2p
 
 import (
 	"context"
+	"fmt"
 	"math"
 	"strings"
 	"sync"
@@ -11,6 +12,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/helpers"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/peerdas"
 	"github.com/OffchainLabs/prysm/v6/cmd/beacon-chain/flags"
+	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
 	"github.com/OffchainLabs/prysm/v6/config/params"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/wrapper"
@@ -23,7 +25,6 @@ import (
 	"github.com/holiman/uint256"
 	"github.com/pkg/errors"
 	"github.com/prysmaticlabs/go-bitfield"
-	"github.com/sirupsen/logrus"
 )
 
 var (
@@ -57,249 +58,302 @@ const blobSubnetLockerVal = 110
 const dataColumnSubnetVal = 150
 
 // nodeFilter returns a function that filters nodes based on the subnet topic and subnet index.
-func (s *Service) nodeFilter(topic string, index uint64) (func(node *enode.Node) bool, error) {
+func (s *Service) nodeFilter(topic string, indices map[uint64]int) (func(node *enode.Node) (map[uint64]bool, error), error) {
 	switch {
 	case strings.Contains(topic, GossipAttestationMessage):
-		return s.filterPeerForAttSubnet(index), nil
+		return s.filterPeerForAttSubnet(indices), nil
 	case strings.Contains(topic, GossipSyncCommitteeMessage):
-		return s.filterPeerForSyncSubnet(index), nil
+		return s.filterPeerForSyncSubnet(indices), nil
 	case strings.Contains(topic, GossipBlobSidecarMessage):
-		return s.filterPeerForBlobSubnet(), nil
+		return s.filterPeerForBlobSubnet(indices), nil
 	case strings.Contains(topic, GossipDataColumnSidecarMessage):
-		return s.filterPeerForDataColumnsSubnet(index), nil
+		return s.filterPeerForDataColumnsSubnet(indices), nil
 	default:
 		return nil, errors.Errorf("no subnet exists for provided topic: %s", topic)
 	}
 }
 
-// searchForPeers performs a network search for peers subscribed to a particular subnet.
-// It exits as soon as one of these conditions is met:
-// - It looped through `batchSize` nodes.
-// - It found `peersToFindCount“ peers corresponding to the `filter` criteria.
-// - Iterator is exhausted.
-func searchForPeers(
-	iterator enode.Iterator,
-	batchPeriod time.Duration,
-	peersToFindCount uint,
-	filter func(node *enode.Node) bool,
-) []*enode.Node {
-	nodeFromNodeID := make(map[enode.ID]*enode.Node)
-	start := time.Now()
+// FindAndDialPeersWithSubnets ensures that our node is connected to at least `minimumPeersPerSubnet`
+// peers for each subnet listed in `subnets`.
+// If, for all subnets, the threshold is met, then this function immediately returns.
+// Otherwise, it searches for new peers for defective subnets, and dials them.
+// If `ctx“ is canceled while searching for peers, search is stopped, but new found peers are still dialed.
+// In this case, the function returns an error.
+func (s *Service) FindAndDialPeersWithSubnets(
+	ctx context.Context,
+	topicFormat string,
+	digest [fieldparams.VersionLength]byte,
+	minimumPeersPerSubnet int,
+	subnets map[uint64]bool,
+) error {
+	ctx, span := trace.StartSpan(ctx, "p2p.FindAndDialPeersWithSubnet")
+	defer span.End()
 
-	for time.Since(start) < batchPeriod && uint(len(nodeFromNodeID)) < peersToFindCount && iterator.Next() {
+	// Return early if the discovery listener isn't set.
+	if s.dv5Listener == nil {
+		return nil
+	}
+
+	// Restrict dials if limit is applied.
+	maxConcurrentDials := math.MaxInt
+	if flags.MaxDialIsActive() {
+		maxConcurrentDials = flags.Get().MaxConcurrentDials
+	}
+
+	defectiveSubnets := s.defectiveSubnets(topicFormat, digest, minimumPeersPerSubnet, subnets)
+	for len(defectiveSubnets) > 0 {
+		// Stop the search/dialing loop if the context is canceled.
+		if err := ctx.Err(); err != nil {
+			return err
+		}
+
+		peersToDial, err := func() ([]*enode.Node, error) {
+			ctx, cancel := context.WithTimeout(ctx, batchPeriod)
+			defer cancel()
+
+			peersToDial, err := s.findPeersWithSubnets(ctx, topicFormat, digest, minimumPeersPerSubnet, defectiveSubnets)
+			if err != nil && !errors.Is(err, context.DeadlineExceeded) {
+				return nil, errors.Wrap(err, "find peers with subnets")
+			}
+
+			return peersToDial, nil
+		}()
+
+		if err != nil {
+			return err
+		}
+
+		// Dial new peers in batches.
+		s.dialPeers(s.ctx, maxConcurrentDials, peersToDial)
+
+		defectiveSubnets = s.defectiveSubnets(topicFormat, digest, minimumPeersPerSubnet, subnets)
+	}
+
+	return nil
+}
+
+// findPeersWithSubnets finds peers subscribed to defective subnets in batches
+// until enough peers are found or the context is canceled.
+// It returns new peers found during the search.
+func (s *Service) findPeersWithSubnets(
+	ctx context.Context,
+	topicFormat string,
+	digest [fieldparams.VersionLength]byte,
+	minimumPeersPerSubnet int,
+	defectiveSubnetsOrigin map[uint64]int,
+) ([]*enode.Node, error) {
+	// Copy the defective subnets map to avoid modifying the original map.
+	defectiveSubnets := make(map[uint64]int, len(defectiveSubnetsOrigin))
+	for k, v := range defectiveSubnetsOrigin {
+		defectiveSubnets[k] = v
+	}
+
+	// Create an discovery iterator to find new peers.
+	iterator := s.dv5Listener.RandomNodes()
+
+	// `iterator.Next` can block indefinitely. `iterator.Close` unblocks it.
+	// So it is important to close the iterator when the context is done to ensure
+	// that the search does not hang indefinitely.
+	go func() {
+		<-ctx.Done()
+		iterator.Close()
+	}()
+
+	// Retrieve the filter function that will be used to filter nodes based on the defective subnets.
+	filter, err := s.nodeFilter(topicFormat, defectiveSubnets)
+	if err != nil {
+		return nil, errors.Wrap(err, "node filter")
+	}
+
+	// Crawl the network for peers subscribed to the defective subnets.
+	nodeByNodeID := make(map[enode.ID]*enode.Node)
+	for len(defectiveSubnets) > 0 && iterator.Next() {
+		if err := ctx.Err(); err != nil {
+			// Convert the map to a slice.
+			peersToDial := make([]*enode.Node, 0, len(nodeByNodeID))
+			for _, node := range nodeByNodeID {
+				peersToDial = append(peersToDial, node)
+			}
+
+			return peersToDial, err
+		}
+
+		// Get all needed subnets that the node is subscribed to.
+		// Skip nodes that are not subscribed to any of the defective subnets.
 		node := iterator.Node()
 
-		// Filter out nodes that do not meet the criteria.
-		if !filter(node) {
+		if !s.filterPeer(node) {
+			continue
+		}
+
+		nodeSubnets, err := filter(node)
+		if err != nil {
+			return nil, errors.Wrap(err, "filter node")
+		}
+		if len(nodeSubnets) == 0 {
 			continue
 		}
 
 		// Remove duplicates, keeping the node with higher seq.
-		prevNode, ok := nodeFromNodeID[node.ID()]
-		if ok && prevNode.Seq() > node.Seq() {
+		existing, ok := nodeByNodeID[node.ID()]
+		if ok && existing.Seq() > node.Seq() {
 			continue
 		}
+		nodeByNodeID[node.ID()] = node
 
-		nodeFromNodeID[node.ID()] = node
+		// We found a new peer. Modify the defective subnets map
+		// and the filter accordingly.
+		for subnet := range defectiveSubnets {
+			if !nodeSubnets[subnet] {
+				continue
+			}
+
+			defectiveSubnets[subnet]--
+
+			if defectiveSubnets[subnet] == 0 {
+				delete(defectiveSubnets, subnet)
+			}
+
+			filter, err = s.nodeFilter(topicFormat, defectiveSubnets)
+			if err != nil {
+				return nil, errors.Wrap(err, "node filter")
+			}
+		}
 	}
 
 	// Convert the map to a slice.
-	nodes := make([]*enode.Node, 0, len(nodeFromNodeID))
-	for _, node := range nodeFromNodeID {
-		nodes = append(nodes, node)
+	peersToDial := make([]*enode.Node, 0, len(nodeByNodeID))
+	for _, node := range nodeByNodeID {
+		peersToDial = append(peersToDial, node)
 	}
 
-	return nodes
+	return peersToDial, nil
 }
 
-// dialPeer dials a peer in a separate goroutine.
-func (s *Service) dialPeer(ctx context.Context, wg *sync.WaitGroup, node *enode.Node) {
-	info, _, err := convertToAddrInfo(node)
-	if err != nil {
-		return
-	}
-
-	if info == nil {
-		return
-	}
-
-	wg.Add(1)
-	go func() {
-		if err := s.connectWithPeer(ctx, *info); err != nil {
-			log.WithError(err).Tracef("Could not connect with peer %s", info.String())
+// defectiveSubnets returns a map of subnets that have fewer than the minimum peer count.
+func (s *Service) defectiveSubnets(
+	topicFormat string,
+	digest [fieldparams.VersionLength]byte,
+	minimumPeersPerSubnet int,
+	subnets map[uint64]bool,
+) map[uint64]int {
+	missingCountPerSubnet := make(map[uint64]int, len(subnets))
+	for subnet := range subnets {
+		topic := fmt.Sprintf(topicFormat, digest, subnet) + s.Encoding().ProtocolSuffix()
+		peers := s.pubsub.ListPeers(topic)
+		peerCount := len(peers)
+		if peerCount < minimumPeersPerSubnet {
+			missingCountPerSubnet[subnet] = minimumPeersPerSubnet - peerCount
 		}
+	}
 
-		wg.Done()
-	}()
+	return missingCountPerSubnet
 }
 
-// FindPeersWithSubnet performs a network search for peers
-// subscribed to a particular subnet. Then it tries to connect
-// with those peers. This method will block until either:
-// - the required amount of peers are found, or
-// - the context is terminated.
-// On some edge cases, this method may hang indefinitely while peers
-// are actually found. In such a case, the user should cancel the context
-// and re-run the method again.
-func (s *Service) FindPeersWithSubnet(
-	ctx context.Context,
-	topic string,
-	index uint64,
-	threshold int,
-) (bool, error) {
-	const minLogInterval = 1 * time.Minute
+// dialPeers dials multiple peers concurrently up to `maxConcurrentDials` at a time.
+// In case of a dial failure, it logs the error but continues dialing other peers.
+func (s *Service) dialPeers(ctx context.Context, maxConcurrentDials int, nodes []*enode.Node) uint {
+	var mut sync.Mutex
 
-	ctx, span := trace.StartSpan(ctx, "p2p.FindPeersWithSubnet")
-	defer span.End()
-
-	span.SetAttributes(trace.Int64Attribute("index", int64(index))) // lint:ignore uintcast -- It's safe to do this for tracing.
-
-	if s.dv5Listener == nil {
-		// Return if discovery isn't set
-		return false, nil
-	}
-
-	topic += s.Encoding().ProtocolSuffix()
-	iterator := s.dv5Listener.RandomNodes()
-	defer iterator.Close()
-
-	filter, err := s.nodeFilter(topic, index)
-	if err != nil {
-		return false, errors.Wrap(err, "node filter")
-	}
-
-	peersSummary := func(topic string, threshold int) (int, int) {
-		// Retrieve how many peers we have for this topic.
-		peerCountForTopic := len(s.pubsub.ListPeers(topic))
-
-		// Compute how many peers we are missing to reach the threshold.
-		missingPeerCountForTopic := max(0, threshold-peerCountForTopic)
-
-		return peerCountForTopic, missingPeerCountForTopic
-	}
-
-	// Compute how many peers we are missing to reach the threshold.
-	peerCountForTopic, missingPeerCountForTopic := peersSummary(topic, threshold)
-
-	// Exit early if we have enough peers.
-	if missingPeerCountForTopic == 0 {
-		return true, nil
-	}
-
-	log := log.WithFields(logrus.Fields{
-		"topic":           topic,
-		"targetPeerCount": threshold,
-	})
-
-	log.WithField("currentPeerCount", peerCountForTopic).Debug("Searching for new peers for a subnet - start")
-
-	lastLogTime := time.Now()
-
-	wg := new(sync.WaitGroup)
-	for {
-		// If the context is done, we can exit the loop. This is the unhappy path.
-		if err := ctx.Err(); err != nil {
-			return false, errors.Errorf(
-				"unable to find requisite number of peers for topic %s - only %d out of %d peers available after searching",
-				topic, peerCountForTopic, threshold,
-			)
+	counter := uint(0)
+	for start := 0; start < len(nodes); start += maxConcurrentDials {
+		if ctx.Err() != nil {
+			return counter
 		}
 
-		// Search for new peers in the network.
-		nodes := searchForPeers(iterator, batchPeriod, uint(missingPeerCountForTopic), filter)
-
-		// Restrict dials if limit is applied.
-		maxConcurrentDials := math.MaxInt
-		if flags.MaxDialIsActive() {
-			maxConcurrentDials = flags.Get().MaxConcurrentDials
-		}
-
-		// Dial the peers in batches.
-		for start := 0; start < len(nodes); start += maxConcurrentDials {
-			stop := min(start+maxConcurrentDials, len(nodes))
-			for _, node := range nodes[start:stop] {
-				s.dialPeer(ctx, wg, node)
+		var wg sync.WaitGroup
+		stop := min(start+maxConcurrentDials, len(nodes))
+		for _, node := range nodes[start:stop] {
+			log := log.WithField("nodeID", node.ID())
+			info, _, err := convertToAddrInfo(node)
+			if err != nil {
+				log.WithError(err).Debug("Could not convert node to addr info")
+				continue
 			}
 
-			// Wait for all dials to be completed.
-			wg.Wait()
+			if info == nil {
+				log.Debug("Nil addr info")
+				continue
+			}
+
+			wg.Add(1)
+			go func() {
+				defer wg.Done()
+				if err := s.connectWithPeer(ctx, *info); err != nil {
+					log.WithError(err).WithField("info", info.String()).Debug("Could not connect with peer")
+					return
+				}
+
+				mut.Lock()
+				defer mut.Unlock()
+				counter++
+			}()
 		}
 
-		peerCountForTopic, missingPeerCountForTopic := peersSummary(topic, threshold)
-
-		// If we have enough peers, we can exit the loop. This is the happy path.
-		if missingPeerCountForTopic == 0 {
-			break
-		}
-
-		if time.Since(lastLogTime) > minLogInterval {
-			lastLogTime = time.Now()
-			log.WithField("currentPeerCount", peerCountForTopic).Debug("Searching for new peers for a subnet - continue")
-		}
+		wg.Wait()
 	}
 
-	log.WithField("currentPeerCount", threshold).Debug("Searching for new peers for a subnet - success")
-	return true, nil
+	return counter
 }
 
-// returns a method with filters peers specifically for a particular attestation subnet.
-func (s *Service) filterPeerForAttSubnet(index uint64) func(node *enode.Node) bool {
-	return func(node *enode.Node) bool {
+// filterPeerForAttSubnet returns a method with filters peers specifically for a particular attestation subnet.
+func (s *Service) filterPeerForAttSubnet(indices map[uint64]int) func(node *enode.Node) (map[uint64]bool, error) {
+	return func(node *enode.Node) (map[uint64]bool, error) {
 		if !s.filterPeer(node) {
-			return false
+			return map[uint64]bool{}, nil
 		}
 
-		subnets, err := attSubnets(node.Record())
+		subnets, err := attestationSubnets(node.Record())
 		if err != nil {
-			return false
+			return nil, errors.Wrap(err, "attestation subnets")
 		}
 
-		return subnets[index]
+		return intersect(indices, subnets), nil
 	}
 }
 
 // returns a method with filters peers specifically for a particular sync subnet.
-func (s *Service) filterPeerForSyncSubnet(index uint64) func(node *enode.Node) bool {
-	return func(node *enode.Node) bool {
+func (s *Service) filterPeerForSyncSubnet(indices map[uint64]int) func(node *enode.Node) (map[uint64]bool, error) {
+	return func(node *enode.Node) (map[uint64]bool, error) {
 		if !s.filterPeer(node) {
-			return false
+			return map[uint64]bool{}, nil
 		}
+
 		subnets, err := syncSubnets(node.Record())
 		if err != nil {
-			return false
+			return nil, errors.Wrap(err, "sync subnets")
 		}
-		indExists := false
-		for _, comIdx := range subnets {
-			if comIdx == index {
-				indExists = true
-				break
-			}
-		}
-		return indExists
+
+		return intersect(indices, subnets), nil
 	}
 }
 
 // returns a method with filters peers specifically for a particular blob subnet.
 // All peers are supposed to be subscribed to all blob subnets.
-func (s *Service) filterPeerForBlobSubnet() func(_ *enode.Node) bool {
-	return func(_ *enode.Node) bool {
-		return true
+func (s *Service) filterPeerForBlobSubnet(indices map[uint64]int) func(_ *enode.Node) (map[uint64]bool, error) {
+	result := make(map[uint64]bool, len(indices))
+	for i := range indices {
+		result[i] = true
+	}
+
+	return func(_ *enode.Node) (map[uint64]bool, error) {
+		return result, nil
 	}
 }
 
 // returns a method with filters peers specifically for a particular data column subnet.
-func (s *Service) filterPeerForDataColumnsSubnet(index uint64) func(node *enode.Node) bool {
-	return func(node *enode.Node) bool {
+func (s *Service) filterPeerForDataColumnsSubnet(indices map[uint64]int) func(node *enode.Node) (map[uint64]bool, error) {
+	return func(node *enode.Node) (map[uint64]bool, error) {
 		if !s.filterPeer(node) {
-			return false
+			return map[uint64]bool{}, nil
 		}
 
 		subnets, err := dataColumnSubnets(node.ID(), node.Record())
 		if err != nil {
-			return false
+			return nil, errors.Wrap(err, "data column subnets")
 		}
 
-		return subnets[index]
+		return intersect(indices, subnets), nil
 	}
 }
 
@@ -475,43 +529,47 @@ func initializeSyncCommSubnets(node *enode.LocalNode) *enode.LocalNode {
 
 // Reads the attestation subnets entry from a node's ENR and determines
 // the committee indices of the attestation subnets the node is subscribed to.
-func attSubnets(record *enr.Record) (map[uint64]bool, error) {
+func attestationSubnets(record *enr.Record) (map[uint64]bool, error) {
 	bitV, err := attBitvector(record)
 	if err != nil {
-		return nil, err
-	}
-	committeeIdxs := make(map[uint64]bool)
-	// lint:ignore uintcast -- subnet count can be safely cast to int.
-	if len(bitV) != byteCount(int(attestationSubnetCount)) {
-		return committeeIdxs, errors.Errorf("invalid bitvector provided, it has a size of %d", len(bitV))
+		return nil, errors.Wrap(err, "att bit vector")
 	}
 
-	for i := uint64(0); i < attestationSubnetCount; i++ {
+	// lint:ignore uintcast -- subnet count can be safely cast to int.
+	if len(bitV) != byteCount(int(attestationSubnetCount)) {
+		return nil, errors.Errorf("invalid bitvector provided, it has a size of %d", len(bitV))
+	}
+
+	indices := make(map[uint64]bool, attestationSubnetCount)
+	for i := range attestationSubnetCount {
 		if bitV.BitAt(i) {
-			committeeIdxs[i] = true
+			indices[i] = true
 		}
 	}
-	return committeeIdxs, nil
+
+	return indices, nil
 }
 
 // Reads the sync subnets entry from a node's ENR and determines
 // the committee indices of the sync subnets the node is subscribed to.
-func syncSubnets(record *enr.Record) ([]uint64, error) {
+func syncSubnets(record *enr.Record) (map[uint64]bool, error) {
 	bitV, err := syncBitvector(record)
 	if err != nil {
-		return nil, err
+		return nil, errors.Wrap(err, "sync bit vector")
 	}
+
 	// lint:ignore uintcast -- subnet count can be safely cast to int.
 	if len(bitV) != byteCount(int(syncCommsSubnetCount)) {
-		return []uint64{}, errors.Errorf("invalid bitvector provided, it has a size of %d", len(bitV))
+		return nil, errors.Errorf("invalid bitvector provided, it has a size of %d", len(bitV))
 	}
-	var committeeIdxs []uint64
-	for i := uint64(0); i < syncCommsSubnetCount; i++ {
+
+	indices := make(map[uint64]bool, syncCommsSubnetCount)
+	for i := range syncCommsSubnetCount {
 		if bitV.BitAt(i) {
-			committeeIdxs = append(committeeIdxs, i)
+			indices[i] = true
 		}
 	}
-	return committeeIdxs, nil
+	return indices, nil
 }
 
 // Retrieve the data columns subnets from a node's ENR and node ID.
@@ -585,3 +643,16 @@ func byteCount(bitCount int) int {
 	}
 	return numOfBytes
 }
+
+// interesect intersects two maps and returns a new map containing only the keys
+// that are present in both maps.
+func intersect(left map[uint64]int, right map[uint64]bool) map[uint64]bool {
+	result := make(map[uint64]bool, min(len(left), len(right)))
+	for i := range left {
+		if right[i] {
+			result[i] = true
+		}
+	}
+
+	return result
+}

beacon-chain/p2p/subnets_test.go

@@ -5,7 +5,6 @@ import (
 	"crypto/rand"
 	"encoding/hex"
 	"fmt"
-	"reflect"
 	"testing"
 	"time"
 
@@ -22,7 +21,7 @@ import (
 	"github.com/prysmaticlabs/go-bitfield"
 )
 
-func TestStartDiscV5_FindPeersWithSubnet(t *testing.T) {
+func TestStartDiscV5_FindAndDialPeersWithSubnet(t *testing.T) {
 	// Topology of this test:
 	//
 	//
@@ -37,7 +36,12 @@ func TestStartDiscV5_FindPeersWithSubnet(t *testing.T) {
 	// In our case: The node i is subscribed to subnet i, with i = 1, 2, 3
 
 	// Define the genesis validators root, to ensure everybody is on the same network.
-	const genesisValidatorRootStr = "0xdeadbeefcafecafedeadbeefcafecafedeadbeefcafecafedeadbeefcafecafe"
+	const (
+		genesisValidatorRootStr = "0xdeadbeefcafecafedeadbeefcafecafedeadbeefcafecafedeadbeefcafecafe"
+		subnetCount             = 3
+		minimumPeersPerSubnet   = 1
+	)
+
 	genesisValidatorsRoot, err := hex.DecodeString(genesisValidatorRootStr[2:])
 	require.NoError(t, err)
 
@@ -87,13 +91,12 @@ func TestStartDiscV5_FindPeersWithSubnet(t *testing.T) {
 
 	// Create 3 nodes, each subscribed to a different subnet.
 	// Each node is connected to the bootstrap node.
-	services := make([]*Service, 0, 3)
+	services := make([]*Service, 0, subnetCount)
 
-	for i := 1; i <= 3; i++ {
-		subnet := uint64(i)
+	for i := uint64(1); i <= subnetCount; i++ {
 		service, err := NewService(ctx, &Config{
 			Discv5BootStrapAddrs: []string{bootNodeENR},
-			MaxPeers:             30,
+			MaxPeers:             0, // Set to 0 to ensure that peers are discovered via subnets search, and not generic peers discovery.
 			UDPPort:              uint(2000 + i),
 			TCPPort:              uint(3000 + i),
 			QUICPort:             uint(3000 + i),
@@ -115,12 +118,13 @@ func TestStartDiscV5_FindPeersWithSubnet(t *testing.T) {
 
 		// Set the ENR `attnets`, used by Prysm to filter peers by subnet.
 		bitV := bitfield.NewBitvector64()
-		bitV.SetBitAt(subnet, true)
+		bitV.SetBitAt(i, true)
 		entry := enr.WithEntry(attSubnetEnrKey, &bitV)
 		service.dv5Listener.LocalNode().Set(entry)
 
 		// Join and subscribe to the subnet, needed by libp2p.
-		topic, err := service.pubsub.Join(fmt.Sprintf(AttestationSubnetTopicFormat, bootNodeForkDigest, subnet) + "/ssz_snappy")
+		topicName := fmt.Sprintf(AttestationSubnetTopicFormat, bootNodeForkDigest, i) + "/ssz_snappy"
+		topic, err := service.pubsub.Join(topicName)
 		require.NoError(t, err)
 
 		_, err = topic.Subscribe()
@@ -160,37 +164,18 @@ func TestStartDiscV5_FindPeersWithSubnet(t *testing.T) {
 		require.NoError(t, err)
 	}()
 
-	// Look up 3 different subnets.
-	exists := make([]bool, 0, 3)
-	for i := 1; i <= 3; i++ {
-		subnet := uint64(i)
-		topic := fmt.Sprintf(AttestationSubnetTopicFormat, bootNodeForkDigest, subnet)
+	subnets := map[uint64]bool{1: true, 2: true, 3: true}
+	defectiveSubnets := service.defectiveSubnets(AttestationSubnetTopicFormat, bootNodeForkDigest, minimumPeersPerSubnet, subnets)
+	require.Equal(t, subnetCount, len(defectiveSubnets))
 
-		exist := false
+	ctxWithTimeOut, cancel := context.WithTimeout(ctx, 5*time.Second)
+	defer cancel()
 
-		// This for loop is used to ensure we don't get stuck in `FindPeersWithSubnet`.
-		// Read the documentation of `FindPeersWithSubnet` for more details.
-		for j := 0; j < 3; j++ {
-			ctxWithTimeOut, cancel := context.WithTimeout(ctx, 5*time.Second)
-			defer cancel()
+	err = service.FindAndDialPeersWithSubnets(ctxWithTimeOut, AttestationSubnetTopicFormat, bootNodeForkDigest, minimumPeersPerSubnet, subnets)
+	require.NoError(t, err)
 
-			exist, err = service.FindPeersWithSubnet(ctxWithTimeOut, topic, subnet, 1)
-			require.NoError(t, err)
-
-			if exist {
-				break
-			}
-		}
-
-		require.NoError(t, err)
-		exists = append(exists, exist)
-
-	}
-
-	// Check if all peers are found.
-	for _, exist := range exists {
-		require.Equal(t, true, exist, "Peer with subnet doesn't exist")
-	}
+	defectiveSubnets = service.defectiveSubnets(AttestationSubnetTopicFormat, bootNodeForkDigest, minimumPeersPerSubnet, subnets)
+	require.Equal(t, 0, len(defectiveSubnets))
 }
 
 func Test_AttSubnets(t *testing.T) {
@@ -305,37 +290,34 @@ func Test_AttSubnets(t *testing.T) {
 			wantErr: false,
 		},
 	}
+
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
 			db, err := enode.OpenDB("")
-			assert.NoError(t, err)
+			require.NoError(t, err)
 
 			priv, _, err := crypto.GenerateSecp256k1Key(rand.Reader)
-			assert.NoError(t, err)
+			require.NoError(t, err)
 
 			convertedKey, err := ecdsaprysm.ConvertFromInterfacePrivKey(priv)
-			assert.NoError(t, err)
+			require.NoError(t, err)
 
 			localNode := enode.NewLocalNode(db, convertedKey)
 			record := tt.record(localNode)
 
-			got, err := attSubnets(record)
+			got, err := attestationSubnets(record)
 			if (err != nil) != tt.wantErr {
-				t.Errorf("syncSubnets() error = %v, wantErr %v", err, tt.wantErr)
+				t.Errorf("attestationSubnets() error = %v, wantErr %v", err, tt.wantErr)
 				return
 			}
 
 			if tt.wantErr {
-				assert.ErrorContains(t, tt.errContains, err)
+				require.ErrorContains(t, tt.errContains, err)
 			}
 
-			want := make(map[uint64]bool, len(tt.want))
+			require.Equal(t, len(tt.want), len(got))
 			for _, subnet := range tt.want {
-				want[subnet] = true
-			}
-
-			if !reflect.DeepEqual(got, want) {
-				t.Errorf("syncSubnets() got = %v, want %v", got, want)
+				require.Equal(t, true, got[subnet])
 			}
 		})
 	}
@@ -494,11 +476,14 @@ func Test_SyncSubnets(t *testing.T) {
 				t.Errorf("syncSubnets() error = %v, wantErr %v", err, tt.wantErr)
 				return
 			}
+
 			if tt.wantErr {
 				assert.ErrorContains(t, tt.errContains, err)
 			}
-			if !reflect.DeepEqual(got, tt.want) {
-				t.Errorf("syncSubnets() got = %v, want %v", got, tt.want)
+
+			require.Equal(t, len(tt.want), len(got))
+			for _, subnet := range tt.want {
+				require.Equal(t, true, got[subnet])
 			}
 		})
 	}

beacon-chain/p2p/testing/fuzz_p2p.go

@@ -68,9 +68,9 @@ func (*FakeP2P) DiscoveryAddresses() ([]multiaddr.Multiaddr, error) {
 	return nil, nil
 }
 
-// FindPeersWithSubnet mocks the p2p func.
-func (*FakeP2P) FindPeersWithSubnet(_ context.Context, _ string, _ uint64, _ int) (bool, error) {
-	return false, nil
+// FindAndDialPeersWithSubnets mocks the p2p func.
+func (*FakeP2P) FindAndDialPeersWithSubnets(ctx context.Context, topicFormat string, digest [fieldparams.VersionLength]byte, minimumPeersPerSubnet int, subnets map[uint64]bool) error {
+	return nil
 }
 
 // RefreshPersistentSubnets mocks the p2p func.
@@ -167,7 +167,7 @@ func (*FakeP2P) BroadcastLightClientFinalityUpdate(_ context.Context, _ interfac
 }
 
 // BroadcastDataColumn -- fake.
-func (*FakeP2P) BroadcastDataColumn(_ [fieldparams.RootLength]byte, _ uint64, _ *ethpb.DataColumnSidecar, _ ...chan<- bool) error {
+func (*FakeP2P) BroadcastDataColumn(_ [fieldparams.RootLength]byte, _ uint64, _ *ethpb.DataColumnSidecar) error {
 	return nil
 }
 

beacon-chain/p2p/testing/mock_broadcaster.go

@@ -63,7 +63,7 @@ func (m *MockBroadcaster) BroadcastLightClientFinalityUpdate(_ context.Context,
 }
 
 // BroadcastDataColumn broadcasts a data column for mock.
-func (m *MockBroadcaster) BroadcastDataColumn([fieldparams.RootLength]byte, uint64, *ethpb.DataColumnSidecar, ...chan<- bool) error {
+func (m *MockBroadcaster) BroadcastDataColumn([fieldparams.RootLength]byte, uint64, *ethpb.DataColumnSidecar) error {
 	m.BroadcastCalled.Store(true)
 	return nil
 }

beacon-chain/p2p/testing/mock_peermanager.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"errors"
 
+	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
 	"github.com/ethereum/go-ethereum/p2p/enode"
 	"github.com/ethereum/go-ethereum/p2p/enr"
 	"github.com/libp2p/go-libp2p/core/host"
@@ -56,9 +57,9 @@ func (m *MockPeerManager) DiscoveryAddresses() ([]multiaddr.Multiaddr, error) {
 // RefreshPersistentSubnets .
 func (*MockPeerManager) RefreshPersistentSubnets() {}
 
-// FindPeersWithSubnet .
-func (*MockPeerManager) FindPeersWithSubnet(_ context.Context, _ string, _ uint64, _ int) (bool, error) {
-	return true, nil
+// FindAndDialPeersWithSubnet .
+func (*MockPeerManager) FindAndDialPeersWithSubnets(ctx context.Context, topicFormat string, digest [fieldparams.VersionLength]byte, minimumPeersPerSubnet int, subnets map[uint64]bool) error {
+	return nil
 }
 
 // AddPingMethod .

beacon-chain/p2p/testing/p2p.go

@@ -224,7 +224,7 @@ func (p *TestP2P) BroadcastLightClientFinalityUpdate(_ context.Context, _ interf
 }
 
 // BroadcastDataColumn broadcasts a data column for mock.
-func (p *TestP2P) BroadcastDataColumn([fieldparams.RootLength]byte, uint64, *ethpb.DataColumnSidecar, ...chan<- bool) error {
+func (p *TestP2P) BroadcastDataColumn([fieldparams.RootLength]byte, uint64, *ethpb.DataColumnSidecar) error {
 	p.BroadcastCalled.Store(true)
 	return nil
 }
@@ -408,9 +408,9 @@ func (p *TestP2P) Peers() *peers.Status {
 	return p.peers
 }
 
-// FindPeersWithSubnet mocks the p2p func.
-func (*TestP2P) FindPeersWithSubnet(_ context.Context, _ string, _ uint64, _ int) (bool, error) {
-	return false, nil
+// FindAndDialPeersWithSubnets mocks the p2p func.
+func (*TestP2P) FindAndDialPeersWithSubnets(ctx context.Context, topicFormat string, digest [fieldparams.VersionLength]byte, minimumPeersPerSubnet int, subnets map[uint64]bool) error {
+	return nil
 }
 
 // RefreshPersistentSubnets mocks the p2p func.

beacon-chain/rpc/endpoints.go

@@ -985,6 +985,16 @@ func (s *Service) beaconEndpoints(
 			handler: server.GetPendingPartialWithdrawals,
 			methods: []string{http.MethodGet},
 		},
+		{
+			template: "/eth/v1/beacon/states/{state_id}/proposer_lookahead",
+			name:     namespace + ".GetProposerLookahead",
+			middleware: []middleware.Middleware{
+				middleware.AcceptHeaderHandler([]string{api.JsonMediaType, api.OctetStreamMediaType}),
+				middleware.AcceptEncodingHeaderHandler(),
+			},
+			handler: server.GetProposerLookahead,
+			methods: []string{http.MethodGet},
+		},
 	}
 }
 
@@ -1138,7 +1148,6 @@ func (s *Service) eventsEndpoints() []endpoint {
 			name:     namespace + ".StreamEvents",
 			middleware: []middleware.Middleware{
 				middleware.AcceptHeaderHandler([]string{api.EventStreamMediaType}),
-				middleware.AcceptEncodingHeaderHandler(),
 			},
 			handler: server.StreamEvents,
 			methods: []string{http.MethodGet},

beacon-chain/rpc/endpoints_test.go

@@ -32,6 +32,7 @@ func Test_endpoints(t *testing.T) {
 		"/eth/v1/beacon/states/{state_id}/pending_deposits":            {http.MethodGet},
 		"/eth/v1/beacon/states/{state_id}/pending_partial_withdrawals": {http.MethodGet},
 		"/eth/v1/beacon/states/{state_id}/pending_consolidations":      {http.MethodGet},
+		"/eth/v1/beacon/states/{state_id}/proposer_lookahead":          {http.MethodGet},
 		"/eth/v1/beacon/headers":                                       {http.MethodGet},
 		"/eth/v1/beacon/headers/{block_id}":                            {http.MethodGet},
 		"/eth/v1/beacon/blinded_blocks":                                {http.MethodPost},

beacon-chain/rpc/eth/beacon/BUILD.bazel

@@ -8,6 +8,7 @@ go_library(
         "handlers_state.go",
         "handlers_validator.go",
         "log.go",
+        "metrics.go",
         "server.go",
     ],
     importpath = "github.com/OffchainLabs/prysm/v6/beacon-chain/rpc/eth/beacon",
@@ -61,6 +62,8 @@ go_library(
         "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
         "@com_github_ethereum_go_ethereum//crypto/kzg4844:go_default_library",
         "@com_github_pkg_errors//:go_default_library",
+        "@com_github_prometheus_client_golang//prometheus:go_default_library",
+        "@com_github_prometheus_client_golang//prometheus/promauto:go_default_library",
         "@com_github_prysmaticlabs_fastssz//:go_default_library",
         "@com_github_sirupsen_logrus//:go_default_library",
     ],
@@ -123,6 +126,7 @@ go_test(
         "@com_github_crate_crypto_go_kzg_4844//:go_default_library",
         "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
         "@com_github_pkg_errors//:go_default_library",
+        "@com_github_prysmaticlabs_fastssz//:go_default_library",
         "@com_github_prysmaticlabs_go_bitfield//:go_default_library",
         "@com_github_sirupsen_logrus//hooks/test:go_default_library",
         "@com_github_stretchr_testify//mock:go_default_library",

beacon-chain/rpc/eth/beacon/handlers.go

@@ -9,6 +9,7 @@ import (
 	"net/http"
 	"strconv"
 	"strings"
+	"time"
 
 	"github.com/OffchainLabs/prysm/v6/api"
 	"github.com/OffchainLabs/prysm/v6/api/server/structs"
@@ -658,6 +659,12 @@ func (s *Server) PublishBlock(w http.ResponseWriter, r *http.Request) {
 // broadcast all given signed blobs. The broadcast behaviour may be adjusted via the
 // `broadcast_validation` query parameter.
 func (s *Server) PublishBlockV2(w http.ResponseWriter, r *http.Request) {
+	start := time.Now()
+	defer func() {
+		duration := time.Since(start).Milliseconds()
+		publishBlockV2Duration.Observe(float64(duration))
+	}()
+
 	ctx, span := trace.StartSpan(r.Context(), "beacon.PublishBlockV2")
 	defer span.End()
 	if shared.IsSyncing(r.Context(), w, s.SyncChecker, s.HeadFetcher, s.TimeFetcher, s.OptimisticModeFetcher) {
@@ -1790,6 +1797,63 @@ func (s *Server) GetPendingPartialWithdrawals(w http.ResponseWriter, r *http.Req
 	}
 }
 
+func (s *Server) GetProposerLookahead(w http.ResponseWriter, r *http.Request) {
+	ctx, span := trace.StartSpan(r.Context(), "beacon.GetProposerLookahead")
+	defer span.End()
+
+	stateId := r.PathValue("state_id")
+	if stateId == "" {
+		httputil.HandleError(w, "state_id is required in URL params", http.StatusBadRequest)
+		return
+	}
+	st, err := s.Stater.State(ctx, []byte(stateId))
+	if err != nil {
+		shared.WriteStateFetchError(w, err)
+		return
+	}
+	if st.Version() < version.Fulu {
+		httputil.HandleError(w, "state_id is prior to fulu", http.StatusBadRequest)
+		return
+	}
+	pl, err := st.ProposerLookahead()
+	if err != nil {
+		httputil.HandleError(w, "Could not get proposer look ahead: "+err.Error(), http.StatusInternalServerError)
+		return
+	}
+	w.Header().Set(api.VersionHeader, version.String(st.Version()))
+	if httputil.RespondWithSsz(r) {
+		sszLen := (*primitives.ValidatorIndex)(nil).SizeSSZ()
+		sszData := make([]byte, len(pl)*sszLen)
+		for i, idx := range pl {
+			copy(sszData[i*sszLen:(i+1)*sszLen], ssz.MarshalUint64([]byte{}, uint64(idx)))
+		}
+		httputil.WriteSsz(w, sszData)
+	} else {
+		isOptimistic, err := helpers.IsOptimistic(ctx, []byte(stateId), s.OptimisticModeFetcher, s.Stater, s.ChainInfoFetcher, s.BeaconDB)
+		if err != nil {
+			httputil.HandleError(w, "Could not check optimistic status: "+err.Error(), http.StatusInternalServerError)
+			return
+		}
+		blockRoot, err := st.LatestBlockHeader().HashTreeRoot()
+		if err != nil {
+			httputil.HandleError(w, "Could not calculate root of latest block header: "+err.Error(), http.StatusInternalServerError)
+			return
+		}
+		isFinalized := s.FinalizationFetcher.IsFinalized(ctx, blockRoot)
+		vi := make([]string, len(pl))
+		for i, v := range pl {
+			vi[i] = strconv.FormatUint(uint64(v), 10)
+		}
+		resp := structs.GetProposerLookaheadResponse{
+			Version:             version.String(st.Version()),
+			ExecutionOptimistic: isOptimistic,
+			Finalized:           isFinalized,
+			Data:                vi,
+		}
+		httputil.WriteJson(w, resp)
+	}
+}
+
 // SerializeItems serializes a slice of items, each of which implements the MarshalSSZ method,
 // into a single byte array.
 func serializeItems[T interface{ MarshalSSZ() ([]byte, error) }](items []T) ([]byte, error) {

beacon-chain/rpc/eth/beacon/handlers_pool_test.go

@@ -1103,9 +1103,9 @@ func TestSubmitSyncCommitteeSignatures(t *testing.T) {
 		require.NoError(t, err)
 		require.Equal(t, 1, len(msgsInPool))
 		assert.Equal(t, primitives.Slot(1), msgsInPool[0].Slot)
-		assert.Equal(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2", hexutil.Encode(msgsInPool[0].BlockRoot))
+		assert.Equal(t, "0xbacd20f09da907734434f052bd4c9503aa16bab1960e89ea20610d08d064481c", hexutil.Encode(msgsInPool[0].BlockRoot))
 		assert.Equal(t, primitives.ValidatorIndex(1), msgsInPool[0].ValidatorIndex)
-		assert.Equal(t, "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505", hexutil.Encode(msgsInPool[0].Signature))
+		assert.Equal(t, "0xb591bd4ca7d745b6e027879645d7c014fecb8c58631af070f7607acc0c1c948a5102a33267f0e4ba41a85b254b07df91185274375b2e6436e37e81d2fd46cb3751f5a6c86efb7499c1796c0c17e122a54ac067bb0f5ff41f3241659cceb0c21c", hexutil.Encode(msgsInPool[0].Signature))
 		assert.Equal(t, true, broadcaster.BroadcastCalled.Load())
 	})
 	t.Run("multiple", func(t *testing.T) {
@@ -2497,23 +2497,23 @@ var (
 	singleSyncCommitteeMsg = `[
   {
     "slot": "1",
-    "beacon_block_root": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+    "beacon_block_root": "0xbacd20f09da907734434f052bd4c9503aa16bab1960e89ea20610d08d064481c",
     "validator_index": "1",
-    "signature": "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"
+    "signature": "0xb591bd4ca7d745b6e027879645d7c014fecb8c58631af070f7607acc0c1c948a5102a33267f0e4ba41a85b254b07df91185274375b2e6436e37e81d2fd46cb3751f5a6c86efb7499c1796c0c17e122a54ac067bb0f5ff41f3241659cceb0c21c"
   }
 ]`
 	multipleSyncCommitteeMsg = `[
   {
     "slot": "1",
-    "beacon_block_root": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+    "beacon_block_root": "0xbacd20f09da907734434f052bd4c9503aa16bab1960e89ea20610d08d064481c",
     "validator_index": "1",
-    "signature": "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"
+    "signature": "0xb591bd4ca7d745b6e027879645d7c014fecb8c58631af070f7607acc0c1c948a5102a33267f0e4ba41a85b254b07df91185274375b2e6436e37e81d2fd46cb3751f5a6c86efb7499c1796c0c17e122a54ac067bb0f5ff41f3241659cceb0c21c"
   },
   {
     "slot": "2",
-    "beacon_block_root": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+    "beacon_block_root": "0x2757f6fd8590925cd000a86a3e543f98a93eae23781783a33e34504729a8ad0c",
     "validator_index": "1",
-    "signature": "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"
+    "signature": "0x99dfe11b6c8b306d2c72eb891926d37922d226ea8e1e7484d6c30fab746494f192b0daa3e40c13f1e335b35238f3362c113455a329b1fab0bc500bc47f643786f49e151d5b5052afb51af57ba5aa34a6051dc90ee4de83a26eb54a895061d89a"
   }
 ]`
 	// signature is invalid
@@ -2523,6 +2523,18 @@ var (
     "beacon_block_root": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
     "validator_index": "1",
     "signature": "foo"
+  },
+  {
+	"slot": "1121",
+	"beacon_block_root": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+	"validator_index": "1",
+	"signature": "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"
+  },
+  {
+	"slot": "1121",
+	"beacon_block_root": "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2",
+	"validator_index": "2",
+	"signature": "0x1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505cc411d61252fb6cb3fa0017b679f8bb2305b26a285fa2737f175668d0dff91cc1b66ac1fb663c9bc59509846d6ec05345bd908eda73e670af888da41af171505"
   }
 ]`
 	// signatures are invalid

beacon-chain/rpc/eth/beacon/handlers_test.go

@@ -43,6 +43,7 @@ import (
 	GoKZG "github.com/crate-crypto/go-kzg-4844"
 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/pkg/errors"
+	ssz "github.com/prysmaticlabs/fastssz"
 	"github.com/prysmaticlabs/go-bitfield"
 	logTest "github.com/sirupsen/logrus/hooks/test"
 	"github.com/stretchr/testify/mock"
@@ -5363,3 +5364,190 @@ func TestGetPendingPartialWithdrawals(t *testing.T) {
 		require.Equal(t, true, resp.Finalized)
 	})
 }
+
+func TestGetProposerLookahead(t *testing.T) {
+	numValidators := 50
+	// Create a Fulu state with proposer lookahead data
+	st, _ := util.DeterministicGenesisStateFulu(t, uint64(numValidators))
+	lookaheadSize := int(params.BeaconConfig().MinSeedLookahead+1) * int(params.BeaconConfig().SlotsPerEpoch)
+	lookahead := make([]primitives.ValidatorIndex, lookaheadSize)
+	for i := 0; i < lookaheadSize; i++ {
+		lookahead[i] = primitives.ValidatorIndex(i % numValidators) // Cycle through validators
+	}
+
+	require.NoError(t, st.SetProposerLookahead(lookahead))
+
+	chainService := &chainMock.ChainService{
+		Optimistic:     false,
+		FinalizedRoots: map[[32]byte]bool{},
+	}
+	server := &Server{
+		Stater: &testutil.MockStater{
+			BeaconState: st,
+		},
+		OptimisticModeFetcher: chainService,
+		FinalizationFetcher:   chainService,
+	}
+
+	t.Run("json response", func(t *testing.T) {
+		req := httptest.NewRequest(http.MethodGet, "http://example.com/eth/v1/beacon/states/{state_id}/proposer_lookahead", nil)
+		req.SetPathValue("state_id", "head")
+		rec := httptest.NewRecorder()
+		rec.Body = new(bytes.Buffer)
+
+		server.GetProposerLookahead(rec, req)
+		require.Equal(t, http.StatusOK, rec.Code)
+		require.Equal(t, "fulu", rec.Header().Get(api.VersionHeader))
+
+		var resp structs.GetProposerLookaheadResponse
+		require.NoError(t, json.Unmarshal(rec.Body.Bytes(), &resp))
+
+		expectedVersion := version.String(st.Version())
+		require.Equal(t, expectedVersion, resp.Version)
+		require.Equal(t, false, resp.ExecutionOptimistic)
+		require.Equal(t, false, resp.Finalized)
+
+		// Verify the data
+		require.Equal(t, lookaheadSize, len(resp.Data))
+		for i := 0; i < lookaheadSize; i++ {
+			expectedIdx := strconv.FormatUint(uint64(i%numValidators), 10)
+			require.Equal(t, expectedIdx, resp.Data[i])
+		}
+	})
+
+	t.Run("ssz response", func(t *testing.T) {
+		req := httptest.NewRequest(http.MethodGet, "http://example.com/eth/v1/beacon/states/{state_id}/proposer_lookahead", nil)
+		req.Header.Set("Accept", "application/octet-stream")
+		req.SetPathValue("state_id", "head")
+		rec := httptest.NewRecorder()
+		rec.Body = new(bytes.Buffer)
+
+		server.GetProposerLookahead(rec, req)
+		require.Equal(t, http.StatusOK, rec.Code)
+		require.Equal(t, "fulu", rec.Header().Get(api.VersionHeader))
+		responseBytes := rec.Body.Bytes()
+		validatorIndexSize := (*primitives.ValidatorIndex)(nil).SizeSSZ()
+		require.Equal(t, len(responseBytes), validatorIndexSize*lookaheadSize)
+
+		recoveredIndices := make([]primitives.ValidatorIndex, lookaheadSize)
+		for i := 0; i < lookaheadSize; i++ {
+			start := i * validatorIndexSize
+			end := start + validatorIndexSize
+
+			idx := ssz.UnmarshallUint64(responseBytes[start:end])
+			recoveredIndices[i] = primitives.ValidatorIndex(idx)
+		}
+		require.DeepEqual(t, lookahead, recoveredIndices)
+	})
+
+	t.Run("pre fulu state", func(t *testing.T) {
+		preEplusSt, _ := util.DeterministicGenesisStateElectra(t, 1)
+		preFuluServer := &Server{
+			Stater: &testutil.MockStater{
+				BeaconState: preEplusSt,
+			},
+			OptimisticModeFetcher: chainService,
+			FinalizationFetcher:   chainService,
+		}
+
+		// Test JSON request
+		req := httptest.NewRequest(http.MethodGet, "http://example.com/eth/v1/beacon/states/{state_id}/proposer_lookahead", nil)
+		req.SetPathValue("state_id", "head")
+		rec := httptest.NewRecorder()
+		rec.Body = new(bytes.Buffer)
+
+		preFuluServer.GetProposerLookahead(rec, req)
+		require.Equal(t, http.StatusBadRequest, rec.Code)
+
+		var errResp struct {
+			Code    int    `json:"code"`
+			Message string `json:"message"`
+		}
+		require.NoError(t, json.Unmarshal(rec.Body.Bytes(), &errResp))
+		require.Equal(t, "state_id is prior to fulu", errResp.Message)
+
+		// Test SSZ request
+		sszReq := httptest.NewRequest(http.MethodGet, "http://example.com/eth/v1/beacon/states/{state_id}/proposer_lookahead", nil)
+		sszReq.Header.Set("Accept", "application/octet-stream")
+		sszReq.SetPathValue("state_id", "head")
+		sszRec := httptest.NewRecorder()
+		sszRec.Body = new(bytes.Buffer)
+
+		preFuluServer.GetProposerLookahead(sszRec, sszReq)
+		require.Equal(t, http.StatusBadRequest, sszRec.Code)
+
+		var sszErrResp struct {
+			Code    int    `json:"code"`
+			Message string `json:"message"`
+		}
+		require.NoError(t, json.Unmarshal(sszRec.Body.Bytes(), &sszErrResp))
+		require.Equal(t, "state_id is prior to fulu", sszErrResp.Message)
+	})
+
+	t.Run("missing state_id parameter", func(t *testing.T) {
+		req := httptest.NewRequest(http.MethodGet, "http://example.com/eth/v1/beacon/states/{state_id}/proposer_lookahead", nil)
+		rec := httptest.NewRecorder()
+		rec.Body = new(bytes.Buffer)
+
+		server.GetProposerLookahead(rec, req)
+		require.Equal(t, http.StatusBadRequest, rec.Code)
+
+		var errResp struct {
+			Code    int    `json:"code"`
+			Message string `json:"message"`
+		}
+		require.NoError(t, json.Unmarshal(rec.Body.Bytes(), &errResp))
+		require.Equal(t, "state_id is required in URL params", errResp.Message)
+	})
+
+	t.Run("optimistic node", func(t *testing.T) {
+		optimisticChainService := &chainMock.ChainService{
+			Optimistic:     true,
+			FinalizedRoots: map[[32]byte]bool{},
+		}
+		optimisticServer := &Server{
+			Stater:                server.Stater,
+			OptimisticModeFetcher: optimisticChainService,
+			FinalizationFetcher:   optimisticChainService,
+		}
+
+		req := httptest.NewRequest(http.MethodGet, "http://example.com/eth/v1/beacon/states/{state_id}/proposer_lookahead", nil)
+		req.SetPathValue("state_id", "head")
+		rec := httptest.NewRecorder()
+		rec.Body = new(bytes.Buffer)
+
+		optimisticServer.GetProposerLookahead(rec, req)
+		require.Equal(t, http.StatusOK, rec.Code)
+
+		var resp structs.GetProposerLookaheadResponse
+		require.NoError(t, json.Unmarshal(rec.Body.Bytes(), &resp))
+		require.Equal(t, true, resp.ExecutionOptimistic)
+	})
+
+	t.Run("finalized node", func(t *testing.T) {
+		blockRoot, err := st.LatestBlockHeader().HashTreeRoot()
+		require.NoError(t, err)
+
+		finalizedChainService := &chainMock.ChainService{
+			Optimistic:     false,
+			FinalizedRoots: map[[32]byte]bool{blockRoot: true},
+		}
+		finalizedServer := &Server{
+			Stater:                server.Stater,
+			OptimisticModeFetcher: finalizedChainService,
+			FinalizationFetcher:   finalizedChainService,
+		}
+
+		req := httptest.NewRequest(http.MethodGet, "http://example.com/eth/v1/beacon/states/{state_id}/proposer_lookahead", nil)
+		req.SetPathValue("state_id", "head")
+		rec := httptest.NewRecorder()
+		rec.Body = new(bytes.Buffer)
+
+		finalizedServer.GetProposerLookahead(rec, req)
+		require.Equal(t, http.StatusOK, rec.Code)
+
+		var resp structs.GetProposerLookaheadResponse
+		require.NoError(t, json.Unmarshal(rec.Body.Bytes(), &resp))
+		require.Equal(t, true, resp.Finalized)
+	})
+}

beacon-chain/rpc/eth/beacon/metrics.go

@@ -0,0 +1,16 @@
+package beacon
+
+import (
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
+)
+
+var (
+	publishBlockV2Duration = promauto.NewHistogram(
+		prometheus.HistogramOpts{
+			Name:    "publish_block_v2_duration_milliseconds",
+			Help:    "Duration of publishBlockV2 endpoint processing in milliseconds",
+			Buckets: []float64{1, 5, 20, 100, 500, 1000, 2000, 5000},
+		},
+	)
+)

beacon-chain/rpc/eth/config/BUILD.bazel

@@ -12,6 +12,7 @@ go_library(
         "//network/forks:go_default_library",
         "//network/httputil:go_default_library",
         "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
+        "@com_github_sirupsen_logrus//:go_default_library",
     ],
 )
 

beacon-chain/rpc/eth/config/handlers.go

@@ -2,6 +2,7 @@ package config
 
 import (
 	"fmt"
+	"math"
 	"net/http"
 	"reflect"
 	"strconv"
@@ -13,6 +14,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/network/forks"
 	"github.com/OffchainLabs/prysm/v6/network/httputil"
 	"github.com/ethereum/go-ethereum/common/hexutil"
+	log "github.com/sirupsen/logrus"
 )
 
 // GetDepositContract retrieves deposit contract address and genesis fork version.
@@ -80,39 +82,108 @@ func GetSpec(w http.ResponseWriter, r *http.Request) {
 	httputil.WriteJson(w, &structs.GetSpecResponse{Data: data})
 }
 
-func prepareConfigSpec() (map[string]string, error) {
-	data := make(map[string]string)
+func convertValueForJSON(v reflect.Value, tag string) interface{} {
+	// Unwrap pointers / interfaces
+	for v.Kind() == reflect.Interface || v.Kind() == reflect.Ptr {
+		if v.IsNil() {
+			return nil
+		}
+		v = v.Elem()
+	}
+
+	switch v.Kind() {
+	// ===== Single byte → 0xAB =====
+	case reflect.Uint8:
+		return hexutil.Encode([]byte{uint8(v.Uint())})
+
+	// ===== Other unsigned numbers → "123" =====
+	case reflect.Uint, reflect.Uint16, reflect.Uint32, reflect.Uint64:
+		return strconv.FormatUint(v.Uint(), 10)
+
+	// ===== Signed numbers → "123" =====
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		return strconv.FormatInt(v.Int(), 10)
+
+	// ===== Raw bytes – encode to hex =====
+	case reflect.Slice:
+		if v.Type().Elem().Kind() == reflect.Uint8 {
+			return hexutil.Encode(v.Bytes())
+		}
+		fallthrough
+	case reflect.Array:
+		if v.Type().Elem().Kind() == reflect.Uint8 {
+			// Need a copy because v.Slice is illegal on arrays directly
+			tmp := make([]byte, v.Len())
+			reflect.Copy(reflect.ValueOf(tmp), v)
+			return hexutil.Encode(tmp)
+		}
+		// Generic slice/array handling
+		n := v.Len()
+		out := make([]interface{}, n)
+		for i := 0; i < n; i++ {
+			out[i] = convertValueForJSON(v.Index(i), tag)
+		}
+		return out
+
+	// ===== Struct =====
+	case reflect.Struct:
+		t := v.Type()
+		m := make(map[string]interface{}, v.NumField())
+		for i := 0; i < v.NumField(); i++ {
+			f := t.Field(i)
+			if !v.Field(i).CanInterface() {
+				continue // unexported
+			}
+			key := f.Tag.Get("json")
+			if key == "" || key == "-" {
+				key = f.Name
+			}
+			m[key] = convertValueForJSON(v.Field(i), tag)
+		}
+		return m
+
+	// ===== Default =====
+	default:
+		log.WithFields(log.Fields{
+			"fn":   "prepareConfigSpec",
+			"tag":  tag,
+			"kind": v.Kind().String(),
+			"type": v.Type().String(),
+		}).Error("Unsupported config field kind; value forwarded verbatim")
+		return v.Interface()
+	}
+}
+
+func prepareConfigSpec() (map[string]interface{}, error) {
+	data := make(map[string]interface{})
 	config := *params.BeaconConfig()
+
 	t := reflect.TypeOf(config)
 	v := reflect.ValueOf(config)
 
 	for i := 0; i < t.NumField(); i++ {
 		tField := t.Field(i)
-		_, isSpecField := tField.Tag.Lookup("spec")
-		if !isSpecField {
-			// Field should not be returned from API.
+		_, isSpec := tField.Tag.Lookup("spec")
+		if !isSpec {
+			continue
+		}
+		if shouldSkip(tField) {
 			continue
 		}
 
-		tagValue := strings.ToUpper(tField.Tag.Get("yaml"))
-		vField := v.Field(i)
-		switch vField.Kind() {
-		case reflect.Int:
-			data[tagValue] = strconv.FormatInt(vField.Int(), 10)
-		case reflect.Uint64:
-			data[tagValue] = strconv.FormatUint(vField.Uint(), 10)
-		case reflect.Slice:
-			data[tagValue] = hexutil.Encode(vField.Bytes())
-		case reflect.Array:
-			data[tagValue] = hexutil.Encode(reflect.ValueOf(&config).Elem().Field(i).Slice(0, vField.Len()).Bytes())
-		case reflect.String:
-			data[tagValue] = vField.String()
-		case reflect.Uint8:
-			data[tagValue] = hexutil.Encode([]byte{uint8(vField.Uint())})
-		default:
-			return nil, fmt.Errorf("unsupported config field type: %s", vField.Kind().String())
-		}
+		tag := strings.ToUpper(tField.Tag.Get("yaml"))
+		val := v.Field(i)
+		data[tag] = convertValueForJSON(val, tag)
 	}
 
 	return data, nil
 }
+
+func shouldSkip(tField reflect.StructField) bool {
+	// Dynamically skip blob schedule if Fulu is not yet scheduled.
+	if params.BeaconConfig().FuluForkEpoch == math.MaxUint64 &&
+		tField.Type == reflect.TypeOf(params.BeaconConfig().BlobSchedule) {
+		return true
+	}
+	return false
+}

beacon-chain/rpc/eth/config/handlers_test.go

@@ -5,6 +5,7 @@ import (
 	"encoding/hex"
 	"encoding/json"
 	"fmt"
+	"math"
 	"net/http"
 	"net/http/httptest"
 	"testing"
@@ -200,7 +201,7 @@ func TestGetSpec(t *testing.T) {
 	data, ok := resp.Data.(map[string]interface{})
 	require.Equal(t, true, ok)
 
-	assert.Equal(t, 175, len(data))
+	assert.Equal(t, 176, len(data))
 	for k, v := range data {
 		t.Run(k, func(t *testing.T) {
 			switch k {
@@ -577,6 +578,11 @@ func TestGetSpec(t *testing.T) {
 				assert.Equal(t, "102", v)
 			case "BLOB_SIDECAR_SUBNET_COUNT_ELECTRA":
 				assert.Equal(t, "103", v)
+			case "BLOB_SCHEDULE":
+				// BLOB_SCHEDULE should be an empty slice when no schedule is defined
+				blobSchedule, ok := v.([]interface{})
+				assert.Equal(t, true, ok)
+				assert.Equal(t, 0, len(blobSchedule))
 			default:
 				t.Errorf("Incorrect key: %s", k)
 			}
@@ -637,3 +643,86 @@ func TestForkSchedule_Ok(t *testing.T) {
 		assert.Equal(t, os.Len(), len(resp.Data))
 	})
 }
+
+func TestGetSpec_BlobSchedule(t *testing.T) {
+	params.SetupTestConfigCleanup(t)
+	config := params.BeaconConfig().Copy()
+	config.FuluForkEpoch = 1
+
+	// Set up a blob schedule with test data
+	config.BlobSchedule = []params.BlobScheduleEntry{
+		{
+			Epoch:            primitives.Epoch(100),
+			MaxBlobsPerBlock: 6,
+		},
+		{
+			Epoch:            primitives.Epoch(200),
+			MaxBlobsPerBlock: 9,
+		},
+	}
+	params.OverrideBeaconConfig(config)
+
+	request := httptest.NewRequest(http.MethodGet, "http://example.com/eth/v1/config/spec", nil)
+	writer := httptest.NewRecorder()
+	writer.Body = &bytes.Buffer{}
+
+	GetSpec(writer, request)
+	require.Equal(t, http.StatusOK, writer.Code)
+	resp := structs.GetSpecResponse{}
+	require.NoError(t, json.Unmarshal(writer.Body.Bytes(), &resp))
+	data, ok := resp.Data.(map[string]interface{})
+	require.Equal(t, true, ok)
+
+	// Verify BLOB_SCHEDULE is present and properly formatted
+	blobScheduleValue, exists := data["BLOB_SCHEDULE"]
+	require.Equal(t, true, exists)
+
+	// Verify it's a slice of maps (actual JSON object, not string)
+	// The JSON unmarshaling converts it to []interface{} with map[string]interface{} entries
+	blobScheduleSlice, ok := blobScheduleValue.([]interface{})
+	require.Equal(t, true, ok)
+
+	// Convert to generic interface for easier testing
+	var blobSchedule []map[string]interface{}
+	for _, entry := range blobScheduleSlice {
+		entryMap, ok := entry.(map[string]interface{})
+		require.Equal(t, true, ok)
+		blobSchedule = append(blobSchedule, entryMap)
+	}
+
+	// Verify the blob schedule content
+	require.Equal(t, 2, len(blobSchedule))
+
+	// Check first entry - values should be strings for consistent API output
+	assert.Equal(t, "100", blobSchedule[0]["EPOCH"])
+	assert.Equal(t, "6", blobSchedule[0]["MAX_BLOBS_PER_BLOCK"])
+
+	// Check second entry - values should be strings for consistent API output
+	assert.Equal(t, "200", blobSchedule[1]["EPOCH"])
+	assert.Equal(t, "9", blobSchedule[1]["MAX_BLOBS_PER_BLOCK"])
+}
+
+func TestGetSpec_BlobSchedule_NotFulu(t *testing.T) {
+	params.SetupTestConfigCleanup(t)
+	config := params.BeaconConfig().Copy()
+	// Fulu not scheduled (default: math.MaxUint64)
+	config.FuluForkEpoch = math.MaxUint64
+	config.BlobSchedule = []params.BlobScheduleEntry{
+		{Epoch: primitives.Epoch(100), MaxBlobsPerBlock: 6},
+	}
+	params.OverrideBeaconConfig(config)
+
+	request := httptest.NewRequest(http.MethodGet, "http://example.com/eth/v1/config/spec", nil)
+	writer := httptest.NewRecorder()
+	writer.Body = &bytes.Buffer{}
+
+	GetSpec(writer, request)
+	require.Equal(t, http.StatusOK, writer.Code)
+	resp := structs.GetSpecResponse{}
+	require.NoError(t, json.Unmarshal(writer.Body.Bytes(), &resp))
+	data, ok := resp.Data.(map[string]interface{})
+	require.Equal(t, true, ok)
+
+	_, exists := data["BLOB_SCHEDULE"]
+	require.Equal(t, false, exists)
+}

beacon-chain/rpc/eth/light-client/BUILD.bazel

@@ -33,9 +33,11 @@ go_test(
     embed = [":go_default_library"],
     deps = [
         "//api/server/structs:go_default_library",
+        "//async/event:go_default_library",
         "//beacon-chain/core/helpers:go_default_library",
         "//beacon-chain/core/light-client:go_default_library",
         "//beacon-chain/db/testing:go_default_library",
+        "//beacon-chain/p2p/testing:go_default_library",
         "//config/fieldparams:go_default_library",
         "//config/params:go_default_library",
         "//consensus-types/blocks:go_default_library",

beacon-chain/rpc/eth/light-client/handlers_test.go

@@ -11,9 +11,11 @@ import (
 	"testing"
 
 	"github.com/OffchainLabs/prysm/v6/api/server/structs"
+	"github.com/OffchainLabs/prysm/v6/async/event"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/helpers"
 	lightclient "github.com/OffchainLabs/prysm/v6/beacon-chain/core/light-client"
 	dbtesting "github.com/OffchainLabs/prysm/v6/beacon-chain/db/testing"
+	p2ptesting "github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/testing"
 	fieldparams "github.com/OffchainLabs/prysm/v6/config/fieldparams"
 	"github.com/OffchainLabs/prysm/v6/config/params"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/blocks"
@@ -52,9 +54,10 @@ func TestLightClientHandler_GetLightClientBootstrap(t *testing.T) {
 			bootstrap, err := lightclient.NewLightClientBootstrapFromBeaconState(l.Ctx, slot, l.State, l.Block)
 			require.NoError(t, err)
 
-			lcStore := lightclient.NewLightClientStore(dbtesting.SetupDB(t))
+			db := dbtesting.SetupDB(t)
+			lcStore := lightclient.NewLightClientStore(db, &p2ptesting.FakeP2P{}, new(event.Feed))
 
-			err = lcStore.SaveLightClientBootstrap(l.Ctx, blockRoot, bootstrap)
+			err = db.SaveLightClientBootstrap(l.Ctx, blockRoot[:], bootstrap)
 			require.NoError(t, err)
 
 			s := &Server{
@@ -95,9 +98,10 @@ func TestLightClientHandler_GetLightClientBootstrap(t *testing.T) {
 			bootstrap, err := lightclient.NewLightClientBootstrapFromBeaconState(l.Ctx, slot, l.State, l.Block)
 			require.NoError(t, err)
 
-			lcStore := lightclient.NewLightClientStore(dbtesting.SetupDB(t))
+			db := dbtesting.SetupDB(t)
+			lcStore := lightclient.NewLightClientStore(db, &p2ptesting.FakeP2P{}, new(event.Feed))
 
-			err = lcStore.SaveLightClientBootstrap(l.Ctx, blockRoot, bootstrap)
+			err = db.SaveLightClientBootstrap(l.Ctx, blockRoot[:], bootstrap)
 			require.NoError(t, err)
 
 			s := &Server{
@@ -139,7 +143,7 @@ func TestLightClientHandler_GetLightClientBootstrap(t *testing.T) {
 
 	t.Run("no bootstrap found", func(t *testing.T) {
 		s := &Server{
-			LCStore: lightclient.NewLightClientStore(dbtesting.SetupDB(t)),
+			LCStore: lightclient.NewLightClientStore(dbtesting.SetupDB(t), &p2ptesting.FakeP2P{}, new(event.Feed)),
 		}
 		request := httptest.NewRequest("GET", "http://foo.com/", nil)
 		request.SetPathValue("block_root", hexutil.Encode([]byte{0x00, 0x01, 0x02}))
@@ -182,7 +186,7 @@ func TestLightClientHandler_GetLightClientByRange(t *testing.T) {
 				}
 
 				s := &Server{
-					LCStore: lightclient.NewLightClientStore(db),
+					LCStore: lightclient.NewLightClientStore(db, &p2ptesting.FakeP2P{}, new(event.Feed)),
 				}
 
 				updatePeriod := startPeriod
@@ -323,7 +327,7 @@ func TestLightClientHandler_GetLightClientByRange(t *testing.T) {
 
 				db := dbtesting.SetupDB(t)
 				s := &Server{
-					LCStore: lightclient.NewLightClientStore(db),
+					LCStore: lightclient.NewLightClientStore(db, &p2ptesting.FakeP2P{}, new(event.Feed)),
 				}
 
 				updates := make([]interfaces.LightClientUpdate, 2)
@@ -443,7 +447,7 @@ func TestLightClientHandler_GetLightClientByRange(t *testing.T) {
 
 		db := dbtesting.SetupDB(t)
 		s := &Server{
-			LCStore: lightclient.NewLightClientStore(db),
+			LCStore: lightclient.NewLightClientStore(db, &p2ptesting.FakeP2P{}, new(event.Feed)),
 		}
 
 		updates := make([]interfaces.LightClientUpdate, 3)
@@ -490,7 +494,7 @@ func TestLightClientHandler_GetLightClientByRange(t *testing.T) {
 
 		db := dbtesting.SetupDB(t)
 		s := &Server{
-			LCStore: lightclient.NewLightClientStore(db),
+			LCStore: lightclient.NewLightClientStore(db, &p2ptesting.FakeP2P{}, new(event.Feed)),
 		}
 
 		updates := make([]interfaces.LightClientUpdate, 3)
@@ -534,7 +538,7 @@ func TestLightClientHandler_GetLightClientByRange(t *testing.T) {
 	t.Run("start period before altair", func(t *testing.T) {
 		db := dbtesting.SetupDB(t)
 		s := &Server{
-			LCStore: lightclient.NewLightClientStore(db),
+			LCStore: lightclient.NewLightClientStore(db, &p2ptesting.FakeP2P{}, new(event.Feed)),
 		}
 		startPeriod := 0
 		url := fmt.Sprintf("http://foo.com/?count=128&start_period=%d", startPeriod)
@@ -557,7 +561,7 @@ func TestLightClientHandler_GetLightClientByRange(t *testing.T) {
 		t.Run("missing update in the middle", func(t *testing.T) {
 			db := dbtesting.SetupDB(t)
 			s := &Server{
-				LCStore: lightclient.NewLightClientStore(db),
+				LCStore: lightclient.NewLightClientStore(db, &p2ptesting.FakeP2P{}, new(event.Feed)),
 			}
 
 			updates := make([]interfaces.LightClientUpdate, 3)
@@ -601,7 +605,7 @@ func TestLightClientHandler_GetLightClientByRange(t *testing.T) {
 		t.Run("missing update at the beginning", func(t *testing.T) {
 			db := dbtesting.SetupDB(t)
 			s := &Server{
-				LCStore: lightclient.NewLightClientStore(db),
+				LCStore: lightclient.NewLightClientStore(db, &p2ptesting.FakeP2P{}, new(event.Feed)),
 			}
 
 			updates := make([]interfaces.LightClientUpdate, 3)
@@ -658,11 +662,11 @@ func TestLightClientHandler_GetLightClientFinalityUpdate(t *testing.T) {
 			ctx := t.Context()
 
 			l := util.NewTestLightClient(t, testVersion)
-			update, err := lightclient.NewLightClientFinalityUpdateFromBeaconState(ctx, l.State.Slot(), l.State, l.Block, l.AttestedState, l.AttestedBlock, l.FinalizedBlock)
+			update, err := lightclient.NewLightClientFinalityUpdateFromBeaconState(ctx, l.State, l.Block, l.AttestedState, l.AttestedBlock, l.FinalizedBlock)
 			require.NoError(t, err)
 
-			s := &Server{LCStore: &lightclient.Store{}}
-			s.LCStore.SetLastFinalityUpdate(update)
+			s := &Server{LCStore: lightclient.NewLightClientStore(dbtesting.SetupDB(t), &p2ptesting.FakeP2P{}, new(event.Feed))}
+			s.LCStore.SetLastFinalityUpdate(update, false)
 
 			request := httptest.NewRequest("GET", "http://foo.com", nil)
 			writer := httptest.NewRecorder()
@@ -683,11 +687,11 @@ func TestLightClientHandler_GetLightClientFinalityUpdate(t *testing.T) {
 			ctx := t.Context()
 
 			l := util.NewTestLightClient(t, testVersion)
-			update, err := lightclient.NewLightClientFinalityUpdateFromBeaconState(ctx, l.State.Slot(), l.State, l.Block, l.AttestedState, l.AttestedBlock, l.FinalizedBlock)
+			update, err := lightclient.NewLightClientFinalityUpdateFromBeaconState(ctx, l.State, l.Block, l.AttestedState, l.AttestedBlock, l.FinalizedBlock)
 			require.NoError(t, err)
 
-			s := &Server{LCStore: &lightclient.Store{}}
-			s.LCStore.SetLastFinalityUpdate(update)
+			s := &Server{LCStore: lightclient.NewLightClientStore(dbtesting.SetupDB(t), &p2ptesting.FakeP2P{}, new(event.Feed))}
+			s.LCStore.SetLastFinalityUpdate(update, false)
 
 			request := httptest.NewRequest("GET", "http://foo.com", nil)
 			request.Header.Add("Accept", "application/octet-stream")
@@ -725,7 +729,7 @@ func TestLightClientHandler_GetLightClientOptimisticUpdate(t *testing.T) {
 	helpers.ClearCache()
 
 	t.Run("no update", func(t *testing.T) {
-		s := &Server{LCStore: &lightclient.Store{}}
+		s := &Server{LCStore: lightclient.NewLightClientStore(dbtesting.SetupDB(t), &p2ptesting.FakeP2P{}, new(event.Feed))}
 
 		request := httptest.NewRequest("GET", "http://foo.com", nil)
 		writer := httptest.NewRecorder()
@@ -738,11 +742,11 @@ func TestLightClientHandler_GetLightClientOptimisticUpdate(t *testing.T) {
 		t.Run(version.String(testVersion), func(t *testing.T) {
 			ctx := t.Context()
 			l := util.NewTestLightClient(t, testVersion)
-			update, err := lightclient.NewLightClientOptimisticUpdateFromBeaconState(ctx, l.State.Slot(), l.State, l.Block, l.AttestedState, l.AttestedBlock)
+			update, err := lightclient.NewLightClientOptimisticUpdateFromBeaconState(ctx, l.State, l.Block, l.AttestedState, l.AttestedBlock)
 			require.NoError(t, err)
 
-			s := &Server{LCStore: &lightclient.Store{}}
-			s.LCStore.SetLastOptimisticUpdate(update)
+			s := &Server{LCStore: lightclient.NewLightClientStore(dbtesting.SetupDB(t), &p2ptesting.FakeP2P{}, new(event.Feed))}
+			s.LCStore.SetLastOptimisticUpdate(update, false)
 
 			request := httptest.NewRequest("GET", "http://foo.com", nil)
 			writer := httptest.NewRecorder()
@@ -762,11 +766,11 @@ func TestLightClientHandler_GetLightClientOptimisticUpdate(t *testing.T) {
 		t.Run(version.String(testVersion)+" SSZ", func(t *testing.T) {
 			ctx := t.Context()
 			l := util.NewTestLightClient(t, testVersion)
-			update, err := lightclient.NewLightClientOptimisticUpdateFromBeaconState(ctx, l.State.Slot(), l.State, l.Block, l.AttestedState, l.AttestedBlock)
+			update, err := lightclient.NewLightClientOptimisticUpdateFromBeaconState(ctx, l.State, l.Block, l.AttestedState, l.AttestedBlock)
 			require.NoError(t, err)
 
-			s := &Server{LCStore: &lightclient.Store{}}
-			s.LCStore.SetLastOptimisticUpdate(update)
+			s := &Server{LCStore: lightclient.NewLightClientStore(dbtesting.SetupDB(t), &p2ptesting.FakeP2P{}, new(event.Feed))}
+			s.LCStore.SetLastOptimisticUpdate(update, false)
 
 			request := httptest.NewRequest("GET", "http://foo.com", nil)
 			request.Header.Add("Accept", "application/octet-stream")

beacon-chain/rpc/eth/node/BUILD.bazel

@@ -19,12 +19,14 @@ go_library(
         "//beacon-chain/p2p/peers/peerdata:go_default_library",
         "//beacon-chain/rpc/eth/shared:go_default_library",
         "//beacon-chain/sync:go_default_library",
+        "//config/params:go_default_library",
         "//monitoring/tracing/trace:go_default_library",
         "//network/httputil:go_default_library",
         "//proto/eth/v1:go_default_library",
         "//proto/migration:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",
         "//runtime/version:go_default_library",
+        "//time/slots:go_default_library",
         "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
         "@com_github_libp2p_go_libp2p//core/peer:go_default_library",
         "@com_github_pkg_errors//:go_default_library",
@@ -47,6 +49,7 @@ go_test(
         "//beacon-chain/p2p/testing:go_default_library",
         "//beacon-chain/rpc/testutil:go_default_library",
         "//beacon-chain/sync/initial-sync/testing:go_default_library",
+        "//config/params:go_default_library",
         "//consensus-types/primitives:go_default_library",
         "//consensus-types/wrapper:go_default_library",
         "//network/httputil:go_default_library",

beacon-chain/rpc/eth/node/handlers.go

@@ -9,10 +9,12 @@ import (
 	"github.com/OffchainLabs/prysm/v6/api/server/structs"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/p2p"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/rpc/eth/shared"
+	"github.com/OffchainLabs/prysm/v6/config/params"
 	"github.com/OffchainLabs/prysm/v6/monitoring/tracing/trace"
 	"github.com/OffchainLabs/prysm/v6/network/httputil"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/eth/v1"
 	"github.com/OffchainLabs/prysm/v6/runtime/version"
+	"github.com/OffchainLabs/prysm/v6/time/slots"
 	"github.com/ethereum/go-ethereum/common/hexutil"
 )
 
@@ -75,17 +77,25 @@ func (s *Server) GetIdentity(w http.ResponseWriter, r *http.Request) {
 		httputil.HandleError(w, "Could not obtain enr: "+err.Error(), http.StatusInternalServerError)
 		return
 	}
-
+	currentEpoch := slots.ToEpoch(s.GenesisTimeFetcher.CurrentSlot())
+	metadata := s.MetadataProvider.Metadata()
+	md := &structs.Metadata{
+		SeqNumber: strconv.FormatUint(s.MetadataProvider.MetadataSeq(), 10),
+		Attnets:   hexutil.Encode(metadata.AttnetsBitfield()),
+	}
+	if currentEpoch >= params.BeaconConfig().AltairForkEpoch {
+		md.Syncnets = hexutil.Encode(metadata.SyncnetsBitfield())
+	}
+	if currentEpoch >= params.BeaconConfig().FuluForkEpoch {
+		md.Cgc = strconv.FormatUint(metadata.CustodyGroupCount(), 10)
+	}
 	resp := &structs.GetIdentityResponse{
 		Data: &structs.Identity{
 			PeerId:             peerId,
 			Enr:                "enr:" + serializedEnr,
 			P2PAddresses:       p2pAddresses,
 			DiscoveryAddresses: discoveryAddresses,
-			Metadata: &structs.Metadata{
-				SeqNumber: strconv.FormatUint(s.MetadataProvider.MetadataSeq(), 10),
-				Attnets:   hexutil.Encode(s.MetadataProvider.Metadata().AttnetsBitfield()),
-			},
+			Metadata:           md,
 		},
 	}
 	httputil.WriteJson(w, resp)

beacon-chain/rpc/eth/node/handlers_test.go

@@ -15,6 +15,7 @@ import (
 	mockp2p "github.com/OffchainLabs/prysm/v6/beacon-chain/p2p/testing"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/rpc/testutil"
 	syncmock "github.com/OffchainLabs/prysm/v6/beacon-chain/sync/initial-sync/testing"
+	"github.com/OffchainLabs/prysm/v6/config/params"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/wrapper"
 	"github.com/OffchainLabs/prysm/v6/network/httputil"
@@ -144,7 +145,14 @@ func TestGetIdentity(t *testing.T) {
 	require.NoError(t, err)
 	attnets := bitfield.NewBitvector64()
 	attnets.SetBitAt(1, true)
-	metadataProvider := &mockp2p.MockMetadataProvider{Data: wrapper.WrappedMetadataV0(&pb.MetaDataV0{SeqNumber: 1, Attnets: attnets})}
+	syncnets := bitfield.NewBitvector4()
+	syncnets.SetBitAt(1, true)
+	metadataProvider := &mockp2p.MockMetadataProvider{Data: wrapper.WrappedMetadataV2(&pb.MetaDataV2{
+		SeqNumber:         1,
+		Attnets:           attnets,
+		Syncnets:          syncnets,
+		CustodyGroupCount: 2,
+	})}
 
 	t.Run("OK", func(t *testing.T) {
 		peerManager := &mockp2p.MockPeerManager{
@@ -154,8 +162,9 @@ func TestGetIdentity(t *testing.T) {
 			DiscoveryAddr: []ma.Multiaddr{discAddr1, discAddr2},
 		}
 		s := &Server{
-			PeerManager:      peerManager,
-			MetadataProvider: metadataProvider,
+			PeerManager:        peerManager,
+			MetadataProvider:   metadataProvider,
+			GenesisTimeFetcher: &mock.ChainService{},
 		}
 
 		request := httptest.NewRequest(http.MethodGet, "http://example.com/eth/v1/node/identity", nil)
@@ -187,6 +196,33 @@ func TestGetIdentity(t *testing.T) {
 		assert.Equal(t, discAddr1.String(), resp.Data.DiscoveryAddresses[0])
 		assert.Equal(t, discAddr2.String(), resp.Data.DiscoveryAddresses[1])
 	})
+	t.Run("OK Fulu", func(t *testing.T) {
+		params.SetupTestConfigCleanup(t)
+		cfg := params.BeaconConfig()
+		cfg.FuluForkEpoch = 0
+		params.OverrideBeaconConfig(cfg)
+		peerManager := &mockp2p.MockPeerManager{
+			Enr:           enrRecord,
+			PID:           "foo",
+			BHost:         &mockp2p.MockHost{Addresses: []ma.Multiaddr{p2pAddr}},
+			DiscoveryAddr: []ma.Multiaddr{discAddr1, discAddr2},
+		}
+		s := &Server{
+			PeerManager:        peerManager,
+			MetadataProvider:   metadataProvider,
+			GenesisTimeFetcher: &mock.ChainService{},
+		}
+
+		request := httptest.NewRequest(http.MethodGet, "http://example.com/eth/v1/node/identity", nil)
+		writer := httptest.NewRecorder()
+		writer.Body = &bytes.Buffer{}
+
+		s.GetIdentity(writer, request)
+		require.Equal(t, http.StatusOK, writer.Code)
+		resp := &structs.GetIdentityResponse{}
+		require.NoError(t, json.Unmarshal(writer.Body.Bytes(), resp))
+		require.Equal(t, "2", resp.Data.Metadata.Cgc)
+	})
 
 	t.Run("ENR failure", func(t *testing.T) {
 		peerManager := &mockp2p.MockPeerManager{

beacon-chain/rpc/eth/validator/handlers_block.go

@@ -118,8 +118,9 @@ func (s *Server) produceBlockV3(ctx context.Context, w http.ResponseWriter, r *h
 	consensusBlockValue, httpError := getConsensusBlockValue(ctx, s.BlockRewardFetcher, v1alpha1resp.Block)
 	if httpError != nil {
 		log.WithError(httpError).Debug("Failed to get consensus block value")
-		// Having the consensus block value is not critical to block production
-		consensusBlockValue = ""
+		// Having the consensus block value is not critical to block production.
+		// We set it to zero to satisfy the specification, which requires a numeric value.
+		consensusBlockValue = "0"
 	}
 
 	w.Header().Set(api.ExecutionPayloadBlindedHeader, fmt.Sprintf("%v", v1alpha1resp.IsBlinded))

beacon-chain/rpc/eth/validator/handlers_block_test.go

@@ -15,6 +15,7 @@ import (
 	rewardtesting "github.com/OffchainLabs/prysm/v6/beacon-chain/rpc/eth/rewards/testing"
 	rpctesting "github.com/OffchainLabs/prysm/v6/beacon-chain/rpc/eth/shared/testing"
 	mockSync "github.com/OffchainLabs/prysm/v6/beacon-chain/sync/initial-sync/testing"
+	"github.com/OffchainLabs/prysm/v6/network/httputil"
 	eth "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/OffchainLabs/prysm/v6/testing/assert"
 	mock2 "github.com/OffchainLabs/prysm/v6/testing/mock"
@@ -408,6 +409,82 @@ func TestProduceBlockV3(t *testing.T) {
 		require.Equal(t, "electra", writer.Header().Get(api.VersionHeader))
 		require.Equal(t, "10000000000", writer.Header().Get(api.ConsensusBlockValueHeader))
 	})
+	t.Run("Fulu", func(t *testing.T) {
+		var block *structs.SignedBeaconBlockContentsFulu
+		err := json.Unmarshal([]byte(rpctesting.FuluBlockContents), &block)
+		require.NoError(t, err)
+		jsonBytes, err := json.Marshal(block.ToUnsigned())
+		require.NoError(t, err)
+		v1alpha1Server := mock2.NewMockBeaconNodeValidatorServer(ctrl)
+		v1alpha1Server.EXPECT().GetBeaconBlock(gomock.Any(), &eth.BlockRequest{
+			Slot:         1,
+			RandaoReveal: bRandao,
+			Graffiti:     bGraffiti,
+			SkipMevBoost: false,
+		}).Return(
+			func() (*eth.GenericBeaconBlock, error) {
+				b, err := block.ToUnsigned().ToGeneric()
+				require.NoError(t, err)
+				b.PayloadValue = "2000"
+				return b, nil
+			}())
+		server := &Server{
+			V1Alpha1Server:        v1alpha1Server,
+			SyncChecker:           syncChecker,
+			OptimisticModeFetcher: chainService,
+			BlockRewardFetcher:    rewardFetcher,
+		}
+		request := httptest.NewRequest(http.MethodGet, fmt.Sprintf("http://foo.example/eth/v3/validator/blocks/1?randao_reveal=%s&graffiti=%s", randao, graffiti), nil)
+		writer := httptest.NewRecorder()
+		writer.Body = &bytes.Buffer{}
+		server.ProduceBlockV3(writer, request)
+		assert.Equal(t, http.StatusOK, writer.Code)
+		want := fmt.Sprintf(`{"version":"fulu","execution_payload_blinded":false,"execution_payload_value":"2000","consensus_block_value":"10000000000","data":%s}`, string(jsonBytes))
+		body := strings.ReplaceAll(writer.Body.String(), "\n", "")
+		require.Equal(t, want, body)
+		require.Equal(t, "false", writer.Header().Get(api.ExecutionPayloadBlindedHeader))
+		require.Equal(t, "2000", writer.Header().Get(api.ExecutionPayloadValueHeader))
+		require.Equal(t, "fulu", writer.Header().Get(api.VersionHeader))
+		require.Equal(t, "10000000000", writer.Header().Get(api.ConsensusBlockValueHeader))
+	})
+	t.Run("Blinded Fulu", func(t *testing.T) {
+		var block *structs.SignedBlindedBeaconBlockFulu
+		err := json.Unmarshal([]byte(rpctesting.BlindedFuluBlock), &block)
+		require.NoError(t, err)
+		jsonBytes, err := json.Marshal(block.Message)
+		require.NoError(t, err)
+		v1alpha1Server := mock2.NewMockBeaconNodeValidatorServer(ctrl)
+		v1alpha1Server.EXPECT().GetBeaconBlock(gomock.Any(), &eth.BlockRequest{
+			Slot:         1,
+			RandaoReveal: bRandao,
+			Graffiti:     bGraffiti,
+			SkipMevBoost: false,
+		}).Return(
+			func() (*eth.GenericBeaconBlock, error) {
+				b, err := block.Message.ToGeneric()
+				require.NoError(t, err)
+				b.PayloadValue = "2000"
+				return b, nil
+			}())
+		server := &Server{
+			V1Alpha1Server:        v1alpha1Server,
+			SyncChecker:           syncChecker,
+			OptimisticModeFetcher: chainService,
+			BlockRewardFetcher:    rewardFetcher,
+		}
+		request := httptest.NewRequest(http.MethodGet, fmt.Sprintf("http://foo.example/eth/v3/validator/blocks/1?randao_reveal=%s&graffiti=%s", randao, graffiti), nil)
+		writer := httptest.NewRecorder()
+		writer.Body = &bytes.Buffer{}
+		server.ProduceBlockV3(writer, request)
+		assert.Equal(t, http.StatusOK, writer.Code)
+		want := fmt.Sprintf(`{"version":"fulu","execution_payload_blinded":true,"execution_payload_value":"2000","consensus_block_value":"10000000000","data":%s}`, string(jsonBytes))
+		body := strings.ReplaceAll(writer.Body.String(), "\n", "")
+		require.Equal(t, want, body)
+		require.Equal(t, "true", writer.Header().Get(api.ExecutionPayloadBlindedHeader))
+		require.Equal(t, "2000", writer.Header().Get(api.ExecutionPayloadValueHeader))
+		require.Equal(t, "fulu", writer.Header().Get(api.VersionHeader))
+		require.Equal(t, "10000000000", writer.Header().Get(api.ConsensusBlockValueHeader))
+	})
 	t.Run("invalid query parameter slot empty", func(t *testing.T) {
 		v1alpha1Server := mock2.NewMockBeaconNodeValidatorServer(ctrl)
 		server := &Server{
@@ -461,6 +538,46 @@ func TestProduceBlockV3(t *testing.T) {
 		assert.Equal(t, http.StatusServiceUnavailable, writer.Code)
 		assert.Equal(t, true, strings.Contains(writer.Body.String(), "Beacon node is currently syncing and not serving request on that endpoint"))
 	})
+	t.Run("0 block value is returned on error", func(t *testing.T) {
+		rewardFetcher := &rewardtesting.MockBlockRewardFetcher{Error: &httputil.DefaultJsonError{}}
+
+		var block *structs.SignedBeaconBlockContentsFulu
+		err := json.Unmarshal([]byte(rpctesting.FuluBlockContents), &block)
+		require.NoError(t, err)
+		jsonBytes, err := json.Marshal(block.ToUnsigned())
+		require.NoError(t, err)
+		v1alpha1Server := mock2.NewMockBeaconNodeValidatorServer(ctrl)
+		v1alpha1Server.EXPECT().GetBeaconBlock(gomock.Any(), &eth.BlockRequest{
+			Slot:         1,
+			RandaoReveal: bRandao,
+			Graffiti:     bGraffiti,
+			SkipMevBoost: false,
+		}).Return(
+			func() (*eth.GenericBeaconBlock, error) {
+				b, err := block.ToUnsigned().ToGeneric()
+				require.NoError(t, err)
+				b.PayloadValue = "2000"
+				return b, nil
+			}())
+		server := &Server{
+			V1Alpha1Server:        v1alpha1Server,
+			SyncChecker:           syncChecker,
+			OptimisticModeFetcher: chainService,
+			BlockRewardFetcher:    rewardFetcher,
+		}
+		request := httptest.NewRequest(http.MethodGet, fmt.Sprintf("http://foo.example/eth/v3/validator/blocks/1?randao_reveal=%s&graffiti=%s", randao, graffiti), nil)
+		writer := httptest.NewRecorder()
+		writer.Body = &bytes.Buffer{}
+		server.ProduceBlockV3(writer, request)
+		assert.Equal(t, http.StatusOK, writer.Code)
+		want := fmt.Sprintf(`{"version":"fulu","execution_payload_blinded":false,"execution_payload_value":"2000","consensus_block_value":"0","data":%s}`, string(jsonBytes))
+		body := strings.ReplaceAll(writer.Body.String(), "\n", "")
+		require.Equal(t, want, body)
+		require.Equal(t, "false", writer.Header().Get(api.ExecutionPayloadBlindedHeader))
+		require.Equal(t, "2000", writer.Header().Get(api.ExecutionPayloadValueHeader))
+		require.Equal(t, "fulu", writer.Header().Get(api.VersionHeader))
+		require.Equal(t, "0", writer.Header().Get(api.ConsensusBlockValueHeader))
+	})
 }
 
 func TestProduceBlockV3SSZ(t *testing.T) {
@@ -960,4 +1077,47 @@ func TestProduceBlockV3SSZ(t *testing.T) {
 		require.Equal(t, "fulu", writer.Header().Get(api.VersionHeader))
 		require.Equal(t, "10000000000", writer.Header().Get(api.ConsensusBlockValueHeader))
 	})
+	t.Run("0 block value is returned on error", func(t *testing.T) {
+		rewardFetcher := &rewardtesting.MockBlockRewardFetcher{Error: &httputil.DefaultJsonError{}}
+
+		var block *structs.SignedBeaconBlockContentsFulu
+		err := json.Unmarshal([]byte(rpctesting.FuluBlockContents), &block)
+		require.NoError(t, err)
+		v1alpha1Server := mock2.NewMockBeaconNodeValidatorServer(ctrl)
+		v1alpha1Server.EXPECT().GetBeaconBlock(gomock.Any(), &eth.BlockRequest{
+			Slot:         1,
+			RandaoReveal: bRandao,
+			Graffiti:     bGraffiti,
+			SkipMevBoost: false,
+		}).Return(
+			func() (*eth.GenericBeaconBlock, error) {
+				b, err := block.ToUnsigned().ToGeneric()
+				require.NoError(t, err)
+				b.PayloadValue = "2000"
+				return b, nil
+			}())
+		server := &Server{
+			V1Alpha1Server:        v1alpha1Server,
+			SyncChecker:           syncChecker,
+			OptimisticModeFetcher: chainService,
+			BlockRewardFetcher:    rewardFetcher,
+		}
+		request := httptest.NewRequest(http.MethodGet, fmt.Sprintf("http://foo.example/eth/v3/validator/blocks/1?randao_reveal=%s&graffiti=%s", randao, graffiti), nil)
+		request.Header.Set("Accept", api.OctetStreamMediaType)
+		writer := httptest.NewRecorder()
+		writer.Body = &bytes.Buffer{}
+		server.ProduceBlockV3(writer, request)
+		assert.Equal(t, http.StatusOK, writer.Code)
+		g, err := block.ToUnsigned().ToGeneric()
+		require.NoError(t, err)
+		bl, ok := g.Block.(*eth.GenericBeaconBlock_Fulu)
+		require.Equal(t, true, ok)
+		ssz, err := bl.Fulu.MarshalSSZ()
+		require.NoError(t, err)
+		require.Equal(t, string(ssz), writer.Body.String())
+		require.Equal(t, "false", writer.Header().Get(api.ExecutionPayloadBlindedHeader))
+		require.Equal(t, "2000", writer.Header().Get(api.ExecutionPayloadValueHeader))
+		require.Equal(t, "fulu", writer.Header().Get(api.VersionHeader))
+		require.Equal(t, "0", writer.Header().Get(api.ConsensusBlockValueHeader))
+	})
 }

beacon-chain/rpc/lookup/stater.go

@@ -44,9 +44,9 @@ type StateNotFoundError struct {
 }
 
 // NewStateNotFoundError creates a new error instance.
-func NewStateNotFoundError(stateRootsSize int) StateNotFoundError {
+func NewStateNotFoundError(stateRootsSize int, stateRoot []byte) StateNotFoundError {
 	return StateNotFoundError{
-		message: fmt.Sprintf("state not found in the last %d state roots", stateRootsSize),
+		message: fmt.Sprintf("state not found in the last %d state roots, looking for state root: %#x", stateRootsSize, stateRoot),
 	}
 }
 
@@ -221,7 +221,7 @@ func (p *BeaconDbStater) stateByRoot(ctx context.Context, stateRoot []byte) (sta
 		}
 	}
 
-	stateNotFoundErr := NewStateNotFoundError(len(headState.StateRoots()))
+	stateNotFoundErr := NewStateNotFoundError(len(headState.StateRoots()), stateRoot)
 	return nil, &stateNotFoundErr
 }
 

beacon-chain/rpc/lookup/stater_test.go

@@ -418,8 +418,9 @@ func TestGetStateRoot(t *testing.T) {
 }
 
 func TestNewStateNotFoundError(t *testing.T) {
-	e := NewStateNotFoundError(100)
-	assert.Equal(t, "state not found in the last 100 state roots", e.message)
+	stateRoot := []byte{0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, 0x20}
+	e := NewStateNotFoundError(100, stateRoot)
+	assert.Equal(t, "state not found in the last 100 state roots, looking for state root: 0x0102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f20", e.message)
 }
 
 func TestStateBySlot_FutureSlot(t *testing.T) {

beacon-chain/rpc/prysm/v1alpha1/beacon/attestations.go

@@ -315,7 +315,7 @@ func (bs *Server) ListIndexedAttestationsElectra(
 // that it was included in a block. The attestation may have expired.
 // Refer to the ethereum consensus specification for more details on how
 // attestations are processed and when they are no longer valid.
-// https://github.com/ethereum/consensus-specs/blob/dev/specs/phase0/beacon-chain.md#attestations
+// https://github.com/ethereum/consensus-specs/blob/master/specs/phase0/beacon-chain.md#attestations
 func (bs *Server) AttestationPool(_ context.Context, req *ethpb.AttestationPoolRequest) (*ethpb.AttestationPoolResponse, error) {
 	var atts []*ethpb.Attestation
 	var err error

beacon-chain/rpc/prysm/v1alpha1/validator/BUILD.bazel

@@ -81,6 +81,7 @@ go_library(
         "//crypto/rand:go_default_library",
         "//encoding/bytesutil:go_default_library",
         "//encoding/ssz:go_default_library",
+        "//io/file:go_default_library",
         "//math:go_default_library",
         "//monitoring/tracing:go_default_library",
         "//monitoring/tracing/trace:go_default_library",

beacon-chain/rpc/prysm/v1alpha1/validator/duties_v2.go

@@ -2,17 +2,26 @@ package validator
 
 import (
 	"context"
+	"fmt"
+	"os"
+	"path/filepath"
+	"runtime"
+	"runtime/pprof"
+	"time"
 
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/helpers"
 	coreTime "github.com/OffchainLabs/prysm/v6/beacon-chain/core/time"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/core/transition"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/rpc/core"
 	"github.com/OffchainLabs/prysm/v6/beacon-chain/state"
+	"github.com/OffchainLabs/prysm/v6/config/features"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	"github.com/OffchainLabs/prysm/v6/encoding/bytesutil"
+	"github.com/OffchainLabs/prysm/v6/io/file"
 	"github.com/OffchainLabs/prysm/v6/monitoring/tracing/trace"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/OffchainLabs/prysm/v6/time/slots"
+	"github.com/sirupsen/logrus"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/status"
 )
@@ -25,7 +34,19 @@ func (vs *Server) GetDutiesV2(ctx context.Context, req *ethpb.DutiesRequest) (*e
 	if vs.SyncChecker.Syncing() {
 		return nil, status.Error(codes.Unavailable, "Syncing to latest head, not ready to respond")
 	}
-	return vs.dutiesv2(ctx, req)
+
+	start := time.Now()
+
+	// Start background profiling that will capture if this takes too long
+	var profileCancel func()
+	if features.Get().SlowDutiesProfile {
+		profileCancel = vs.startSlowDutiesProfiler(start, len(req.PublicKeys), req.Epoch)
+		defer profileCancel()
+	}
+
+	resp, err := vs.dutiesv2(ctx, req)
+
+	return resp, err
 }
 
 // Compute the validator duties from the head state's corresponding epoch
@@ -270,3 +291,138 @@ func populateCommitteeFields(duty *ethpb.DutiesV2Response_Duty, la *helpers.Lite
 	duty.ValidatorCommitteeIndex = la.ValidatorCommitteeIndex
 	duty.AttesterSlot = la.AttesterSlot
 }
+
+// startSlowDutiesProfiler starts background profiling that triggers after 2s
+// Returns a cancel function that should be called when the operation completes
+func (vs *Server) startSlowDutiesProfiler(startTime time.Time, numValidators int, epoch primitives.Epoch) func() {
+	ctx, cancel := context.WithCancel(context.Background())
+
+	go func() {
+		// Wait for 2 seconds
+		select {
+		case <-time.After(2 * time.Second):
+			// Operation is taking too long, start profiling
+			vs.captureSlowDutiesProfile(startTime, numValidators, epoch, ctx)
+		case <-ctx.Done():
+			// Operation completed before 2s, no profiling needed
+			return
+		}
+	}()
+
+	return cancel
+}
+
+// captureSlowDutiesProfile captures CPU and mutex profiles when GetDutiesV2 is slow
+func (vs *Server) captureSlowDutiesProfile(startTime time.Time, numValidators int, epoch primitives.Epoch, ctx context.Context) {
+	timestamp := time.Now().Format("20060102-150405")
+
+	// Get the datadir from the database path and create debug subdirectory
+	// Cast to Database interface to access DatabasePath method
+	dbWithPath, ok := vs.BeaconDB.(interface{ DatabasePath() string })
+	if !ok {
+		log.Error("Cannot access database path for profiling - database does not implement DatabasePath method")
+		return
+	}
+	dbPath := dbWithPath.DatabasePath()
+	profileDir := filepath.Join(filepath.Dir(dbPath), "debug")
+
+	// Create profile directory if it doesn't exist
+	if err := file.MkdirAll(profileDir); err != nil {
+		log.WithError(err).Warn("Failed to create profile directory")
+		return
+	}
+
+	currentDuration := time.Since(startTime)
+	log.WithFields(logrus.Fields{
+		"currentDuration": currentDuration,
+		"numValidators":   numValidators,
+		"epoch":           epoch,
+		"profileDir":      profileDir,
+	}).Warn("GetDutiesV2 taking longer than 2s, capturing profiles")
+
+	// Start CPU profiling immediately
+	cpuFile, err := os.Create(fmt.Sprintf("%s/cpu-duties-%s.prof", profileDir, timestamp))
+	if err != nil {
+		log.WithError(err).Warn("Failed to create CPU profile file")
+	} else {
+		if err := pprof.StartCPUProfile(cpuFile); err != nil {
+			log.WithError(err).Warn("Failed to start CPU profile")
+			if closeErr := cpuFile.Close(); closeErr != nil {
+				log.WithError(closeErr).Warn("Failed to close CPU profile file")
+			}
+		} else {
+			// Profile for up to 10 seconds or until context is cancelled
+			go func() {
+				defer func() {
+					pprof.StopCPUProfile()
+					if closeErr := cpuFile.Close(); closeErr != nil {
+						log.WithError(closeErr).Warn("Failed to close CPU profile file")
+					}
+					log.WithField("file", cpuFile.Name()).Info("CPU profile captured")
+				}()
+
+				select {
+				case <-time.After(10 * time.Second):
+					// Stop profiling after 10s max
+				case <-ctx.Done():
+					// Stop profiling when operation completes
+				}
+			}()
+		}
+	}
+
+	// Enable mutex profiling
+	runtime.SetMutexProfileFraction(1)
+
+	// Capture snapshot profiles immediately
+	vs.captureSnapshotProfiles(profileDir, timestamp)
+}
+
+// captureSnapshotProfiles captures point-in-time profiles
+func (vs *Server) captureSnapshotProfiles(profileDir, timestamp string) {
+	// Capture mutex profile
+	mutexFile, err := os.Create(fmt.Sprintf("%s/mutex-duties-%s.prof", profileDir, timestamp))
+	if err != nil {
+		log.WithError(err).Warn("Failed to create mutex profile file")
+	} else {
+		if err := pprof.Lookup("mutex").WriteTo(mutexFile, 0); err != nil {
+			log.WithError(err).Warn("Failed to write mutex profile")
+		} else {
+			log.WithField("file", mutexFile.Name()).Info("Mutex profile captured")
+		}
+		if closeErr := mutexFile.Close(); closeErr != nil {
+			log.WithError(closeErr).Warn("Failed to close mutex profile file")
+		}
+	}
+
+	// Capture goroutine profile
+	goroutineFile, err := os.Create(fmt.Sprintf("%s/goroutine-duties-%s.prof", profileDir, timestamp))
+	if err != nil {
+		log.WithError(err).Warn("Failed to create goroutine profile file")
+	} else {
+		if err := pprof.Lookup("goroutine").WriteTo(goroutineFile, 0); err != nil {
+			log.WithError(err).Warn("Failed to write goroutine profile")
+		} else {
+			log.WithField("file", goroutineFile.Name()).Info("Goroutine profile captured")
+		}
+		if closeErr := goroutineFile.Close(); closeErr != nil {
+			log.WithError(closeErr).Warn("Failed to close goroutine profile file")
+		}
+	}
+
+	// Capture heap profile
+	heapFile, err := os.Create(fmt.Sprintf("%s/heap-duties-%s.prof", profileDir, timestamp))
+	if err != nil {
+		log.WithError(err).Warn("Failed to create heap profile file")
+	} else {
+		runtime.GC() // Force GC before heap profile
+		if err := pprof.Lookup("heap").WriteTo(heapFile, 0); err != nil {
+			log.WithError(err).Warn("Failed to write heap profile")
+		} else {
+			log.WithField("file", heapFile.Name()).Info("Heap profile captured")
+		}
+		if closeErr := heapFile.Close(); closeErr != nil {
+			log.WithError(closeErr).Warn("Failed to close heap profile file")
+		}
+	}
+}

beacon-chain/rpc/prysm/v1alpha1/validator/proposer_bellatrix.go

@@ -5,7 +5,6 @@ import (
 	"context"
 	"fmt"
 	"math/big"
-	"strings"
 	"time"
 
 	"github.com/OffchainLabs/prysm/v6/api/client/builder"
@@ -19,7 +18,6 @@ import (
 	"github.com/OffchainLabs/prysm/v6/encoding/ssz"
 	"github.com/OffchainLabs/prysm/v6/monitoring/tracing"
 	"github.com/OffchainLabs/prysm/v6/monitoring/tracing/trace"
-	"github.com/OffchainLabs/prysm/v6/network/forks"
 	enginev1 "github.com/OffchainLabs/prysm/v6/proto/engine/v1"
 	"github.com/OffchainLabs/prysm/v6/runtime/version"
 	"github.com/OffchainLabs/prysm/v6/time/slots"
@@ -220,16 +218,10 @@ func (vs *Server) getPayloadHeaderFromBuilder(
 	if signedBid == nil || signedBid.IsNil() {
 		return nil, errors.New("builder returned nil bid")
 	}
-	fork, err := forks.Fork(slots.ToEpoch(slot))
-	if err != nil {
-		return nil, errors.Wrap(err, "unable to get fork information")
-	}
-	forkName, ok := params.BeaconConfig().ForkVersionNames[bytesutil.ToBytes4(fork.CurrentVersion)]
-	if !ok {
-		return nil, errors.New("unable to find current fork in schedule")
-	}
-	if !strings.EqualFold(version.String(signedBid.Version()), forkName) {
-		return nil, fmt.Errorf("builder bid response version: %d is different from head block version: %d for epoch %d", signedBid.Version(), b.Version(), slots.ToEpoch(slot))
+	bidVersion := signedBid.Version()
+	headBlockVersion := b.Version()
+	if !isVersionCompatible(bidVersion, headBlockVersion) {
+		return nil, fmt.Errorf("builder bid response version: %d is not compatible with head block version: %d for epoch %d", bidVersion, headBlockVersion, slots.ToEpoch(slot))
 	}
 
 	bid, err := signedBid.Message()
@@ -466,3 +458,19 @@ func expectedGasLimit(parentGasLimit, proposerGasLimit uint64) uint64 {
 	}
 	return proposerGasLimit
 }
+
+// isVersionCompatible checks if a builder bid version is compatible with the head block version.
+func isVersionCompatible(bidVersion, headBlockVersion int) bool {
+	// Exact version match is always compatible
+	if bidVersion == headBlockVersion {
+		return true
+	}
+
+	// Allow Electra bids for Fulu blocks - they have compatible payload formats
+	if bidVersion == version.Electra && headBlockVersion == version.Fulu {
+		return true
+	}
+
+	// For all other cases, require exact version match
+	return false
+}

beacon-chain/rpc/prysm/v1alpha1/validator/proposer_bellatrix_test.go

@@ -25,6 +25,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/encoding/ssz"
 	v1 "github.com/OffchainLabs/prysm/v6/proto/engine/v1"
 	ethpb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
+	"github.com/OffchainLabs/prysm/v6/runtime/version"
 	"github.com/OffchainLabs/prysm/v6/testing/require"
 	"github.com/OffchainLabs/prysm/v6/testing/util"
 	"github.com/OffchainLabs/prysm/v6/time/slots"
@@ -156,7 +157,7 @@ func TestServer_setExecutionData(t *testing.T) {
 			HasConfigured: true,
 			Cfg:           &builderTest.Config{BeaconDB: beaconDB},
 		}
-		wb, err := blocks.NewSignedBeaconBlock(util.NewBeaconBlockBellatrix())
+		wb, err := blocks.NewSignedBeaconBlock(util.NewBeaconBlockCapella())
 		require.NoError(t, err)
 		chain := &blockchainTest.ChainService{ForkChoiceStore: doublylinkedtree.New(), Genesis: time.Now(), Block: wb}
 		vs.ForkchoiceFetcher = chain
@@ -973,7 +974,7 @@ func TestServer_getPayloadHeader(t *testing.T) {
 					return wb
 				}(),
 			},
-			err: "is different from head block version",
+			err: "builder bid response version: 3 is not compatible with head block version: 2 for epoch 1",
 		},
 		{
 			name: "different bid version during hard fork",
@@ -982,7 +983,7 @@ func TestServer_getPayloadHeader(t *testing.T) {
 			},
 			fetcher: &blockchainTest.ChainService{
 				Block: func() interfaces.ReadOnlySignedBeaconBlock {
-					wb, err := blocks.NewSignedBeaconBlock(util.NewBeaconBlockBellatrix())
+					wb, err := blocks.NewSignedBeaconBlock(util.NewBeaconBlockCapella())
 					require.NoError(t, err)
 					wb.SetSlot(primitives.Slot(fakeCapellaEpoch) * params.BeaconConfig().SlotsPerEpoch)
 					return wb
@@ -1005,6 +1006,86 @@ func TestServer_getPayloadHeader(t *testing.T) {
 			},
 			err: "incorrect header gas limit 30000000 != 31000000",
 		},
+		{
+			name: "electra bid with fulu head block - compatible",
+			mock: func() *builderTest.MockBuilderService {
+				// Create Electra bid
+				requests := &v1.ExecutionRequests{
+					Deposits: []*v1.DepositRequest{
+						{
+							Pubkey:                bytesutil.PadTo([]byte{byte('a')}, fieldparams.BLSPubkeyLength),
+							WithdrawalCredentials: bytesutil.PadTo([]byte{byte('b')}, fieldparams.RootLength),
+							Amount:                params.BeaconConfig().MinActivationBalance,
+							Signature:             bytesutil.PadTo([]byte{byte('c')}, fieldparams.BLSSignatureLength),
+							Index:                 0,
+						},
+					},
+					Withdrawals: []*v1.WithdrawalRequest{
+						{
+							SourceAddress:   bytesutil.PadTo([]byte{byte('d')}, common.AddressLength),
+							ValidatorPubkey: bytesutil.PadTo([]byte{byte('e')}, fieldparams.BLSPubkeyLength),
+							Amount:          params.BeaconConfig().MinActivationBalance,
+						},
+					},
+					Consolidations: []*v1.ConsolidationRequest{
+						{
+							SourceAddress: bytesutil.PadTo([]byte{byte('f')}, common.AddressLength),
+							SourcePubkey:  bytesutil.PadTo([]byte{byte('g')}, fieldparams.BLSPubkeyLength),
+							TargetPubkey:  bytesutil.PadTo([]byte{byte('h')}, fieldparams.BLSPubkeyLength),
+						},
+					},
+				}
+
+				electraBid := &ethpb.BuilderBidElectra{
+					Header: &v1.ExecutionPayloadHeaderDeneb{
+						FeeRecipient:     make([]byte, fieldparams.FeeRecipientLength),
+						StateRoot:        make([]byte, fieldparams.RootLength),
+						ReceiptsRoot:     make([]byte, fieldparams.RootLength),
+						LogsBloom:        make([]byte, fieldparams.LogsBloomLength),
+						PrevRandao:       make([]byte, fieldparams.RootLength),
+						BaseFeePerGas:    make([]byte, fieldparams.RootLength),
+						BlockHash:        make([]byte, fieldparams.RootLength),
+						TransactionsRoot: bytesutil.PadTo([]byte{1}, fieldparams.RootLength),
+						ParentHash:       params.BeaconConfig().ZeroHash[:],
+						Timestamp:        uint64(ti.Unix()),
+						BlockNumber:      2,
+						WithdrawalsRoot:  make([]byte, fieldparams.RootLength),
+						BlobGasUsed:      123,
+						ExcessBlobGas:    456,
+						GasLimit:         gasLimit,
+					},
+					Pubkey:             sk.PublicKey().Marshal(),
+					Value:              bytesutil.PadTo([]byte{1, 2, 3}, 32),
+					BlobKzgCommitments: [][]byte{bytesutil.PadTo([]byte{2}, fieldparams.BLSPubkeyLength)},
+					ExecutionRequests:  requests,
+				}
+
+				d := params.BeaconConfig().DomainApplicationBuilder
+				domain, err := signing.ComputeDomain(d, nil, nil)
+				require.NoError(t, err)
+				sr, err := signing.ComputeSigningRoot(electraBid, domain)
+				require.NoError(t, err)
+
+				sBidElectra := &ethpb.SignedBuilderBidElectra{
+					Message:   electraBid,
+					Signature: sk.Sign(sr[:]).Marshal(),
+				}
+
+				return &builderTest.MockBuilderService{
+					BidElectra: sBidElectra,
+				}
+			}(),
+			fetcher: &blockchainTest.ChainService{
+				Block: func() interfaces.ReadOnlySignedBeaconBlock {
+					// Create Fulu head block
+					wb, err := blocks.NewSignedBeaconBlock(util.NewBeaconBlockFulu())
+					require.NoError(t, err)
+					wb.SetSlot(primitives.Slot(params.BeaconConfig().BellatrixForkEpoch) * params.BeaconConfig().SlotsPerEpoch)
+					return wb
+				}(),
+			},
+			// Should succeed because Electra bids are compatible with Fulu head blocks
+		},
 	}
 	for _, tc := range tests {
 		t.Run(tc.name, func(t *testing.T) {
@@ -1222,3 +1303,107 @@ func Test_expectedGasLimit(t *testing.T) {
 		})
 	}
 }
+
+func TestIsVersionCompatible(t *testing.T) {
+
+	tests := []struct {
+		name             string
+		bidVersion       int
+		headBlockVersion int
+		want             bool
+	}{
+		{
+			name:             "Exact version match - Bellatrix",
+			bidVersion:       version.Bellatrix,
+			headBlockVersion: version.Bellatrix,
+			want:             true,
+		},
+		{
+			name:             "Exact version match - Capella",
+			bidVersion:       version.Capella,
+			headBlockVersion: version.Capella,
+			want:             true,
+		},
+		{
+			name:             "Exact version match - Deneb",
+			bidVersion:       version.Deneb,
+			headBlockVersion: version.Deneb,
+			want:             true,
+		},
+		{
+			name:             "Exact version match - Electra",
+			bidVersion:       version.Electra,
+			headBlockVersion: version.Electra,
+			want:             true,
+		},
+		{
+			name:             "Exact version match - Fulu",
+			bidVersion:       version.Fulu,
+			headBlockVersion: version.Fulu,
+			want:             true,
+		},
+		{
+			name:             "Electra bid with Fulu head block - Compatible",
+			bidVersion:       version.Electra,
+			headBlockVersion: version.Fulu,
+			want:             true,
+		},
+		{
+			name:             "Fulu bid with Electra head block - Not compatible",
+			bidVersion:       version.Fulu,
+			headBlockVersion: version.Electra,
+			want:             false,
+		},
+		{
+			name:             "Deneb bid with Electra head block - Not compatible",
+			bidVersion:       version.Deneb,
+			headBlockVersion: version.Electra,
+			want:             false,
+		},
+		{
+			name:             "Electra bid with Deneb head block - Not compatible",
+			bidVersion:       version.Electra,
+			headBlockVersion: version.Deneb,
+			want:             false,
+		},
+		{
+			name:             "Capella bid with Deneb head block - Not compatible",
+			bidVersion:       version.Capella,
+			headBlockVersion: version.Deneb,
+			want:             false,
+		},
+		{
+			name:             "Bellatrix bid with Capella head block - Not compatible",
+			bidVersion:       version.Bellatrix,
+			headBlockVersion: version.Capella,
+			want:             false,
+		},
+		{
+			name:             "Phase0 bid with Altair head block - Not compatible",
+			bidVersion:       version.Phase0,
+			headBlockVersion: version.Altair,
+			want:             false,
+		},
+		{
+			name:             "Deneb bid with Fulu head block - Not compatible",
+			bidVersion:       version.Deneb,
+			headBlockVersion: version.Fulu,
+			want:             false,
+		},
+		{
+			name:             "Capella bid with Fulu head block - Not compatible",
+			bidVersion:       version.Capella,
+			headBlockVersion: version.Fulu,
+			want:             false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := isVersionCompatible(tt.bidVersion, tt.headBlockVersion)
+			if got != tt.want {
+				t.Errorf("isVersionCompatible(%d, %d) = %v, want %v", tt.bidVersion, tt.headBlockVersion, got, tt.want)
+			}
+		})
+	}
+}

beacon-chain/rpc/prysm/v1alpha1/validator/status.go

@@ -262,7 +262,7 @@ func (vs *Server) activationStatus(
 // It cannot faithfully attest to the head block of the chain, since it has not fully verified that block.
 //
 // Spec:
-// https://github.com/ethereum/consensus-specs/blob/dev/sync/optimistic.md
+// https://github.com/ethereum/consensus-specs/blob/master/sync/optimistic.md
 func (vs *Server) optimisticStatus(ctx context.Context) error {
 	if slots.ToEpoch(vs.TimeFetcher.CurrentSlot()) < params.BeaconConfig().BellatrixForkEpoch {
 		return nil

beacon-chain/sync/BUILD.bazel

@@ -212,6 +212,7 @@ go_test(
     shard_count = 4,
     deps = [
         "//async/abool:go_default_library",
+        "//async/event:go_default_library",
         "//beacon-chain/blockchain:go_default_library",
         "//beacon-chain/blockchain/kzg:go_default_library",
         "//beacon-chain/blockchain/testing:go_default_library",

beacon-chain/sync/backfill/service.go

@@ -17,6 +17,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/time/slots"
 	"github.com/libp2p/go-libp2p/core/peer"
 	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
 )
 
 type Service struct {
@@ -211,7 +212,7 @@ func (s *Service) importBatches(ctx context.Context) {
 		_, err := s.batchImporter(ctx, current, ib, s.store)
 		if err != nil {
 			log.WithError(err).WithFields(ib.logFields()).Debug("Backfill batch failed to import")
-			s.downscore(ib)
+			s.downscorePeer(ib.blockPid, "backfillBatchImportError")
 			s.batchSeq.update(ib.withState(batchErrRetryable))
 			// If a batch fails, the subsequent batches are no longer considered importable.
 			break
@@ -336,10 +337,6 @@ func (s *Service) initBatches() error {
 	return nil
 }
 
-func (s *Service) downscore(b batch) {
-	s.p2p.Peers().Scorers().BadResponsesScorer().Increment(b.blockPid)
-}
-
 func (*Service) Stop() error {
 	return nil
 }
@@ -383,3 +380,8 @@ func (s *Service) WaitForCompletion() error {
 		return nil
 	}
 }
+
+func (s *Service) downscorePeer(peerID peer.ID, reason string) {
+	newScore := s.p2p.Peers().Scorers().BadResponsesScorer().Increment(peerID)
+	log.WithFields(logrus.Fields{"peerID": peerID, "reason": reason, "newScore": newScore}).Debug("Downscore peer")
+}

beacon-chain/sync/data_columns_reconstruct.go

@@ -21,9 +21,9 @@ const (
 	broadcastMissingDataColumnsSlack           = 2 * time.Second
 )
 
-// reconstructSaveBroadcastDataColumnSidecars reconstructs if possible and
-// needed all data column sidecars. Then, it saves into the store missing
-// sidecars. After a delay, it broadcasts in the background not seen via gossip
+// reconstructSaveBroadcastDataColumnSidecars reconstructs, if possible,
+// all data column sidecars. Then, it saves missing sidecars to the store.
+// After a delay, it broadcasts in the background not seen via gossip
 // (but reconstructed) sidecars.
 func (s *Service) reconstructSaveBroadcastDataColumnSidecars(
 	ctx context.Context,
@@ -33,15 +33,15 @@ func (s *Service) reconstructSaveBroadcastDataColumnSidecars(
 ) error {
 	startTime := time.Now()
 
+	// Lock to prevent concurrent reconstructions.
+	s.reconstructionLock.Lock()
+	defer s.reconstructionLock.Unlock()
+
 	// Get the columns we store.
 	storedDataColumns := s.cfg.dataColumnStorage.Summary(root)
 	storedColumnsCount := storedDataColumns.Count()
 	numberOfColumns := params.BeaconConfig().NumberOfColumns
 
-	// Lock to prevent concurrent reconstructions.
-	s.reconstructionLock.Lock()
-	defer s.reconstructionLock.Unlock()
-
 	// If reconstruction is not possible or if all columns are already stored, exit early.
 	if storedColumnsCount < peerdas.MinimumColumnsCountToReconstruct() || storedColumnsCount == numberOfColumns {
 		return nil
@@ -55,7 +55,7 @@ func (s *Service) reconstructSaveBroadcastDataColumnSidecars(
 		return errors.Wrap(err, "peer info")
 	}
 
-	// Load all the possible data columns sidecars, to minimize reconstruction time.
+	// Load all the possible data column sidecars, to minimize reconstruction time.
 	verifiedSidecars, err := s.cfg.dataColumnStorage.Get(root, nil)
 	if err != nil {
 		return errors.Wrap(err, "get data column sidecars")
@@ -76,7 +76,7 @@ func (s *Service) reconstructSaveBroadcastDataColumnSidecars(
 		}
 	}
 
-	// Save the data columns sidecars in the database.
+	// Save the data column sidecars to the database.
 	// Note: We do not call `receiveDataColumn`, because it will ignore
 	// incoming data columns via gossip while we did not broadcast (yet) the reconstructed data columns.
 	if err := s.cfg.dataColumnStorage.Save(toSaveSidecars); err != nil {
@@ -95,7 +95,7 @@ func (s *Service) reconstructSaveBroadcastDataColumnSidecars(
 		"reconstructionAndSaveDuration": time.Since(startTime),
 	}).Debug("Data columns reconstructed and saved")
 
-	// Update reconstruction metrics
+	// Update reconstruction metrics.
 	dataColumnReconstructionHistogram.Observe(float64(time.Since(startTime).Milliseconds()))
 	dataColumnReconstructionCounter.Add(float64(len(reconstructedSidecars) - len(verifiedSidecars)))
 

beacon-chain/sync/error.go

@@ -109,7 +109,12 @@ func isValidStreamError(err error) bool {
 
 func closeStream(stream network.Stream, log *logrus.Entry) {
 	if err := stream.Close(); isValidStreamError(err) {
-		log.WithError(err).Debugf("Could not reset stream with protocol %s", stream.Protocol())
+		log.WithError(err).
+			WithFields(logrus.Fields{
+				"protocol": stream.Protocol(),
+				"peer":     stream.Conn().RemotePeer(),
+			}).
+			Debug("Could not close stream")
 	}
 }
 
@@ -118,7 +123,12 @@ func closeStreamAndWait(stream network.Stream, log *logrus.Entry) {
 		_err := stream.Reset()
 		_ = _err
 		if isValidStreamError(err) {
-			log.WithError(err).Debugf("Could not reset stream with protocol %s", stream.Protocol())
+			log.WithError(err).
+				WithFields(logrus.Fields{
+					"protocol": stream.Protocol(),
+					"peer":     stream.Conn().RemotePeer(),
+				}).
+				Debug("Could not reset stream")
 		}
 		return
 	}

beacon-chain/sync/initial-sync/blocks_queue.go

@@ -337,14 +337,15 @@ func (q *blocksQueue) onDataReceivedEvent(ctx context.Context) eventHandlerFn {
 					}
 				}
 			}
+
 			if errors.Is(response.err, beaconsync.ErrInvalidFetchedData) {
-				// Peer returned invalid data, penalize.
-				q.blocksFetcher.p2p.Peers().Scorers().BadResponsesScorer().Increment(response.blocksFrom)
-				log.WithField("pid", response.blocksFrom).Debug("Peer is penalized for invalid blocks")
-			} else if errors.Is(response.err, verification.ErrBlobInvalid) {
-				q.blocksFetcher.p2p.Peers().Scorers().BadResponsesScorer().Increment(response.blobsFrom)
-				log.WithField("pid", response.blobsFrom).Debug("Peer is penalized for invalid blob response")
+				q.downscorePeer(response.blocksFrom, "invalidBlocks")
 			}
+
+			if errors.Is(response.err, verification.ErrBlobInvalid) {
+				q.downscorePeer(response.blobsFrom, "invalidBlobs")
+			}
+
 			return m.state, response.err
 		}
 		m.fetched = *response
@@ -455,6 +456,11 @@ func (q *blocksQueue) onProcessSkippedEvent(ctx context.Context) eventHandlerFn
 	}
 }
 
+func (q *blocksQueue) downscorePeer(peerID peer.ID, reason string) {
+	newScore := q.blocksFetcher.p2p.Peers().Scorers().BadResponsesScorer().Increment(peerID)
+	log.WithFields(logrus.Fields{"peerID": peerID, "reason": reason, "newScore": newScore}).Debug("Downscore peer")
+}
+
 // onCheckStaleEvent is an event that allows to mark stale epochs,
 // so that they can be re-processed.
 func onCheckStaleEvent(ctx context.Context) eventHandlerFn {

beacon-chain/sync/initial-sync/blocks_queue_test.go

@@ -522,7 +522,7 @@ func TestBlocksQueue_onDataReceivedEvent(t *testing.T) {
 		})
 		assert.ErrorContains(t, beaconsync.ErrInvalidFetchedData.Error(), err)
 		assert.Equal(t, stateScheduled, updatedState)
-		assert.LogsContain(t, hook, "msg=\"Peer is penalized for invalid blocks\" pid=ZiCa")
+		assert.LogsContain(t, hook, "Downscore peer")
 	})
 
 	t.Run("transition ok", func(t *testing.T) {

beacon-chain/sync/initial-sync/round_robin.go

@@ -14,6 +14,7 @@ import (
 	"github.com/OffchainLabs/prysm/v6/consensus-types/interfaces"
 	"github.com/OffchainLabs/prysm/v6/consensus-types/primitives"
 	"github.com/OffchainLabs/prysm/v6/time/slots"
+	"github.com/libp2p/go-libp2p/core/peer"
 	"github.com/paulbellamy/ratecounter"
 	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
@@ -345,12 +346,11 @@ func isPunishableError(err error) bool {
 func (s *Service) updatePeerScorerStats(data *blocksQueueFetchedData, count uint64, err error) {
 	if isPunishableError(err) {
 		if verification.IsBlobValidationFailure(err) {
-			log.WithError(err).WithField("peer_id", data.blobsFrom).Warn("Downscoring peer for invalid blobs")
-			s.cfg.P2P.Peers().Scorers().BadResponsesScorer().Increment(data.blobsFrom)
+			s.downscorePeer(data.blobsFrom, "invalidBlobs")
 		} else {
-			log.WithError(err).WithField("peer_id", data.blocksFrom).Warn("Downscoring peer for invalid blocks")
-			s.cfg.P2P.Peers().Scorers().BadResponsesScorer().Increment(data.blocksFrom)
+			s.downscorePeer(data.blocksFrom, "invalidBlocks")
 		}
+
 		// If the error is punishable, exit here so that we don't give them credit for providing bad blocks.
 		return
 	}
@@ -376,3 +376,8 @@ func (s *Service) isProcessedBlock(ctx context.Context, blk blocks.ROBlock) bool
 	}
 	return false
 }
+
+func (s *Service) downscorePeer(peerID peer.ID, reason string) {
+	newScore := s.cfg.P2P.Peers().Scorers().BadResponsesScorer().Increment(peerID)
+	log.WithFields(logrus.Fields{"peerID": peerID, "reason": reason, "newScore": newScore}).Debug("Downscore peer")
+}

beacon-chain/sync/metrics.go

@@ -236,7 +236,7 @@ func (s *Service) updateMetrics() {
 	if err != nil {
 		log.WithError(err).Debugf("Could not compute fork digest")
 	}
-	indices := s.aggregatorSubnetIndices(s.cfg.clock.CurrentSlot())
+	indices := aggregatorSubnetIndices(s.cfg.clock.CurrentSlot())
 	syncIndices := cache.SyncSubnetIDs.GetAllSubnets(slots.ToEpoch(s.cfg.clock.CurrentSlot()))
 	attTopic := p2p.GossipTypeMapping[reflect.TypeOf(&pb.Attestation{})]
 	syncTopic := p2p.GossipTypeMapping[reflect.TypeOf(&pb.SyncCommitteeMessage{})]

beacon-chain/sync/rate_limiter.go

@@ -6,6 +6,7 @@ import (
 	"time"
 
 	"github.com/libp2p/go-libp2p/core/network"
+	"github.com/libp2p/go-libp2p/core/peer"
 	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
 	"github.com/trailofbits/go-mutexasserts"
@@ -122,7 +123,7 @@ func (l *limiter) validateRequest(stream network.Stream, amt uint64) error {
 
 	collector, err := l.retrieveCollector(topic)
 	if err != nil {
-		return err
+		return errors.Wrap(err, "retrieve collector")
 	}
 
 	remaining := collector.Remaining(remotePeer.String())
@@ -131,7 +132,7 @@ func (l *limiter) validateRequest(stream network.Stream, amt uint64) error {
 		amt = 1
 	}
 	if amt > uint64(remaining) {
-		l.p2p.Peers().Scorers().BadResponsesScorer().Increment(remotePeer)
+		l.downscorePeer(remotePeer, topic, "rateLimitExceeded")
 		writeErrorResponseToStream(responseCodeInvalidRequest, p2ptypes.ErrRateLimited.Error(), stream, l.p2p)
 		return p2ptypes.ErrRateLimited
 	}
@@ -139,22 +140,20 @@ func (l *limiter) validateRequest(stream network.Stream, amt uint64) error {
 }
 
 // This is used to validate all incoming rpc streams from external peers.
-func (l *limiter) validateRawRpcRequest(stream network.Stream) error {
+func (l *limiter) validateRawRpcRequest(stream network.Stream, amt uint64) error {
 	l.RLock()
 	defer l.RUnlock()
 
-	topic := rpcLimiterTopic
-
-	collector, err := l.retrieveCollector(topic)
+	remotePeer := stream.Conn().RemotePeer()
+	collector, err := l.retrieveCollector(rpcLimiterTopic)
 	if err != nil {
 		return err
 	}
 	key := stream.Conn().RemotePeer().String()
 	remaining := collector.Remaining(key)
-	// Treat each request as a minimum of 1.
-	amt := int64(1)
-	if amt > remaining {
-		l.p2p.Peers().Scorers().BadResponsesScorer().Increment(stream.Conn().RemotePeer())
+
+	if amt > uint64(remaining) {
+		l.downscorePeer(remotePeer, rpcLimiterTopic, "rawRateLimitExceeded")
 		writeErrorResponseToStream(responseCodeInvalidRequest, p2ptypes.ErrRateLimited.Error(), stream, l.p2p)
 		return p2ptypes.ErrRateLimited
 	}
@@ -233,3 +232,13 @@ func (l *limiter) retrieveCollector(topic string) (*leakybucket.Collector, error
 func (_ *limiter) topicLogger(topic string) *logrus.Entry {
 	return log.WithField("rateLimiter", topic)
 }
+
+func (l *limiter) downscorePeer(peerID peer.ID, topic, reason string) {
+	newScore := l.p2p.Peers().Scorers().BadResponsesScorer().Increment(peerID)
+	log.WithFields(logrus.Fields{
+		"peerID":   peerID.String(),
+		"reason":   reason,
+		"newScore": newScore,
+		"topic":    topic,
+	}).Debug("Downscore peer")
+}

beacon-chain/sync/rate_limiter_test.go

@@ -85,16 +85,16 @@ func TestRateLimiter_ExceedRawCapacity(t *testing.T) {
 	require.NoError(t, err, "could not create stream")
 
 	for i := 0; i < 2*defaultBurstLimit; i++ {
-		err = rlimiter.validateRawRpcRequest(stream)
+		err = rlimiter.validateRawRpcRequest(stream, 1)
 		rlimiter.addRawStream(stream)
 		require.NoError(t, err, "could not validate incoming request")
 	}
 	// Triggers rate limit error on burst.
-	assert.ErrorContains(t, p2ptypes.ErrRateLimited.Error(), rlimiter.validateRawRpcRequest(stream))
+	assert.ErrorContains(t, p2ptypes.ErrRateLimited.Error(), rlimiter.validateRawRpcRequest(stream, 1))
 
 	// Make Peer bad.
 	for i := 0; i < defaultBurstLimit; i++ {
-		assert.ErrorContains(t, p2ptypes.ErrRateLimited.Error(), rlimiter.validateRawRpcRequest(stream))
+		assert.ErrorContains(t, p2ptypes.ErrRateLimited.Error(), rlimiter.validateRawRpcRequest(stream, 1))
 	}
 	assert.NotNil(t, p1.Peers().IsBad(p2.PeerID()), "peer is not marked as a bad peer")
 	require.NoError(t, stream.Close(), "could not close stream")

beacon-chain/sync/rpc.go

@@ -20,6 +20,7 @@ import (
 	"github.com/libp2p/go-libp2p/core/network"
 	"github.com/pkg/errors"
 	ssz "github.com/prysmaticlabs/fastssz"
+	"github.com/sirupsen/logrus"
 )
 
 var (
@@ -39,7 +40,7 @@ type rpcHandler func(context.Context, interface{}, libp2pcore.Stream) error
 
 // rpcHandlerByTopicFromFork returns the RPC handlers for a given fork index.
 func (s *Service) rpcHandlerByTopicFromFork(forkIndex int) (map[string]rpcHandler, error) {
-	// Fulu: https://github.com/ethereum/consensus-specs/blob/dev/specs/fulu/p2p-interface.md#messages
+	// Fulu: https://github.com/ethereum/consensus-specs/blob/master/specs/fulu/p2p-interface.md#messages
 	if forkIndex >= version.Fulu {
 		return map[string]rpcHandler{
 			p2p.RPCGoodByeTopicV1:                   s.goodbyeRPCHandler,
@@ -54,7 +55,7 @@ func (s *Service) rpcHandlerByTopicFromFork(forkIndex int) (map[string]rpcHandle
 		}, nil
 	}
 
-	// Electra: https://github.com/ethereum/consensus-specs/blob/dev/specs/electra/p2p-interface.md#messages
+	// Electra: https://github.com/ethereum/consensus-specs/blob/master/specs/electra/p2p-interface.md#messages
 	if forkIndex >= version.Electra {
 		return map[string]rpcHandler{
 			p2p.RPCStatusTopicV1:              s.statusRPCHandler,
@@ -68,7 +69,7 @@ func (s *Service) rpcHandlerByTopicFromFork(forkIndex int) (map[string]rpcHandle
 		}, nil
 	}
 
-	// Deneb: https://github.com/ethereum/consensus-specs/blob/dev/specs/deneb/p2p-interface.md#messages
+	// Deneb: https://github.com/ethereum/consensus-specs/blob/master/specs/deneb/p2p-interface.md#messages
 	if forkIndex >= version.Deneb {
 		return map[string]rpcHandler{
 			p2p.RPCStatusTopicV1:              s.statusRPCHandler,
@@ -82,9 +83,9 @@ func (s *Service) rpcHandlerByTopicFromFork(forkIndex int) (map[string]rpcHandle
 		}, nil
 	}
 
-	// Capella: https://github.com/ethereum/consensus-specs/blob/dev/specs/capella/p2p-interface.md#messages
-	// Bellatrix: https://github.com/ethereum/consensus-specs/blob/dev/specs/bellatrix/p2p-interface.md#messages
-	// Altair: https://github.com/ethereum/consensus-specs/blob/dev/specs/altair/p2p-interface.md#messages
+	// Capella: https://github.com/ethereum/consensus-specs/blob/master/specs/capella/p2p-interface.md#messages
+	// Bellatrix: https://github.com/ethereum/consensus-specs/blob/master/specs/bellatrix/p2p-interface.md#messages
+	// Altair: https://github.com/ethereum/consensus-specs/blob/master/specs/altair/p2p-interface.md#messages
 	if forkIndex >= version.Altair {
 		handler := map[string]rpcHandler{
 			p2p.RPCStatusTopicV1:        s.statusRPCHandler,
@@ -105,7 +106,7 @@ func (s *Service) rpcHandlerByTopicFromFork(forkIndex int) (map[string]rpcHandle
 		return handler, nil
 	}
 
-	// PhaseO: https://github.com/ethereum/consensus-specs/blob/dev/specs/phase0/p2p-interface.md#messages
+	// PhaseO: https://github.com/ethereum/consensus-specs/blob/master/specs/phase0/p2p-interface.md#messages
 	if forkIndex >= version.Phase0 {
 		return map[string]rpcHandler{
 			p2p.RPCStatusTopicV1:        s.statusRPCHandler,
@@ -238,7 +239,7 @@ func (s *Service) registerRPC(baseTopic string, handle rpcHandler) {
 		defer span.End()
 		span.SetAttributes(trace.StringAttribute("topic", topic))
 		span.SetAttributes(trace.StringAttribute("peer", remotePeer.String()))
-		log := log.WithField("peer", stream.Conn().RemotePeer().String()).WithField("topic", string(stream.Protocol()))
+		log := log.WithFields(logrus.Fields{"peer": remotePeer.String(), "topic": string(stream.Protocol())})
 
 		// Check before hand that peer is valid.
 		if err := s.cfg.p2p.Peers().IsBad(remotePeer); err != nil {
@@ -248,7 +249,7 @@ func (s *Service) registerRPC(baseTopic string, handle rpcHandler) {
 			return
 		}
 		// Validate request according to peer limits.
-		if err := s.rateLimiter.validateRawRpcRequest(stream); err != nil {
+		if err := s.rateLimiter.validateRawRpcRequest(stream, 1); err != nil {
 			log.WithError(err).Debug("Could not validate rpc request from peer")
 			return
 		}
@@ -304,7 +305,7 @@ func (s *Service) registerRPC(baseTopic string, handle rpcHandler) {
 			if err := s.cfg.p2p.Encoding().DecodeWithMaxLength(stream, msg); err != nil {
 				logStreamErrors(err, topic)
 				tracing.AnnotateError(span, err)
-				s.cfg.p2p.Peers().Scorers().BadResponsesScorer().Increment(stream.Conn().RemotePeer())
+				s.downscorePeer(remotePeer, "registerRpcError")
 				return
 			}
 			if err := handle(ctx, msg, stream); err != nil {
@@ -324,7 +325,7 @@ func (s *Service) registerRPC(baseTopic string, handle rpcHandler) {
 			if err := s.cfg.p2p.Encoding().DecodeWithMaxLength(stream, msg); err != nil {
 				logStreamErrors(err, topic)
 				tracing.AnnotateError(span, err)
-				s.cfg.p2p.Peers().Scorers().BadResponsesScorer().Increment(stream.Conn().RemotePeer())
+				s.downscorePeer(remotePeer, "registerRpcError")
 				return
 			}
 			if err := handle(ctx, nTyp.Elem().Interface(), stream); err != nil {

beacon-chain/sync/rpc_beacon_blocks_by_range.go

@@ -15,6 +15,7 @@ import (
 	pb "github.com/OffchainLabs/prysm/v6/proto/prysm/v1alpha1"
 	"github.com/OffchainLabs/prysm/v6/time/slots"
 	libp2pcore "github.com/libp2p/go-libp2p/core"
+	"github.com/libp2p/go-libp2p/core/peer"
 	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
 )
@@ -43,7 +44,7 @@ func (s *Service) beaconBlocksByRangeRPCHandler(ctx context.Context, msg interfa
 	rp, err := validateRangeRequest(m, s.cfg.clock.CurrentSlot())
 	if err != nil {
 		s.writeErrorResponseToStream(responseCodeInvalidRequest, err.Error(), stream)
-		s.cfg.p2p.Peers().Scorers().BadResponsesScorer().Increment(remotePeer)
+		s.downscorePeer(remotePeer, "beaconBlocksByRangeRPCHandlerValidationError")
 		tracing.AnnotateError(span, err)
 		return err
 	}
@@ -201,3 +202,13 @@ func (s *Service) writeBlockBatchToStream(ctx context.Context, batch blockBatch,
 
 	return nil
 }
+
+func (s *Service) downscorePeer(peerID peer.ID, reason string, fields ...logrus.Fields) {
+	log := log
+	for _, field := range fields {
+		log = log.WithFields(field)
+	}
+
+	newScore := s.cfg.p2p.Peers().Scorers().BadResponsesScorer().Increment(peerID)
+	log.WithFields(logrus.Fields{"peerID": peerID, "reason": reason, "newScore": newScore}).Debug("Downscore peer")
+}

beacon-chain/sync/rpc_beacon_blocks_by_root.go

@@ -92,9 +92,11 @@ func (s *Service) beaconBlocksRootRPCHandler(ctx context.Context, msg interface{
 		return errors.New("no block roots provided")
 	}
 
+	remotePeer := stream.Conn().RemotePeer()
+
 	currentEpoch := slots.ToEpoch(s.cfg.clock.CurrentSlot())
 	if uint64(len(blockRoots)) > params.MaxRequestBlock(currentEpoch) {
-		s.cfg.p2p.Peers().Scorers().BadResponsesScorer().Increment(stream.Conn().RemotePeer())
+		s.downscorePeer(remotePeer, "beaconBlocksRootRPCHandlerTooManyRoots")
 		s.writeErrorResponseToStream(responseCodeInvalidRequest, "requested more than the max block limit", stream)
 		return errors.New("requested more than the max block limit")
 	}

beacon-chain/sync/rpc_blob_sidecars_by_range.go

@@ -74,10 +74,13 @@ func (s *Service) blobSidecarsByRangeRPCHandler(ctx context.Context, msg interfa
 	if err := s.rateLimiter.validateRequest(stream, 1); err != nil {
 		return err
 	}
+
+	remotePeer := stream.Conn().RemotePeer()
+
 	rp, err := validateBlobsByRange(r, s.cfg.chain.CurrentSlot())
 	if err != nil {
 		s.writeErrorResponseToStream(responseCodeInvalidRequest, err.Error(), stream)
-		s.cfg.p2p.Peers().Scorers().BadResponsesScorer().Increment(stream.Conn().RemotePeer())
+		s.downscorePeer(remotePeer, "blobSidecarsByRangeRpcHandlerValidationError")
 		tracing.AnnotateError(span, err)
 		return err
 	}
@@ -87,7 +90,7 @@ func (s *Service) blobSidecarsByRangeRPCHandler(ctx context.Context, msg interfa
 	defer ticker.Stop()
 	batcher, err := newBlockRangeBatcher(rp, s.cfg.beaconDB, s.rateLimiter, s.cfg.chain.IsCanonical, ticker)
 	if err != nil {
-		log.WithError(err).Info("error in BlobSidecarsByRange batch")
+		log.WithError(err).Error("Cannot create new block range batcher")
 		s.writeErrorResponseToStream(responseCodeServerError, p2ptypes.ErrGeneric.Error(), stream)
 		tracing.AnnotateError(span, err)
 		return err
@@ -112,7 +115,7 @@ func (s *Service) blobSidecarsByRangeRPCHandler(ctx context.Context, msg interfa
 		}
 	}
 	if err := batch.error(); err != nil {
-		log.WithError(err).Debug("error in BlobSidecarsByRange batch")
+		log.WithError(err).Debug("Error in BlobSidecarsByRange batch")
 
 		// If a rate limit is hit, it means an error response has already been sent and the stream has been closed.
 		if !errors.Is(err, p2ptypes.ErrRateLimited) {

beacon-chain/sync/rpc_blob_sidecars_by_root.go

@@ -39,7 +39,7 @@ func (s *Service) blobSidecarByRootRPCHandler(ctx context.Context, msg interface
 	cs := s.cfg.clock.CurrentSlot()
 	remotePeer := stream.Conn().RemotePeer()
 	if err := validateBlobByRootRequest(blobIdents, cs); err != nil {
-		s.cfg.p2p.Peers().Scorers().BadResponsesScorer().Increment(remotePeer)
+		s.downscorePeer(remotePeer, "blobSidecarsByRootRpcHandlerValidationError")
 		s.writeErrorResponseToStream(responseCodeInvalidRequest, err.Error(), stream)
 		return err
 	}

beacon-chain/sync/rpc_data_column_sidecars_by_range.go

@@ -65,7 +65,7 @@ func (s *Service) dataColumnSidecarsByRangeRPCHandler(ctx context.Context, msg i
 	rangeParameters, err := validateDataColumnsByRange(request, s.cfg.chain.CurrentSlot())
 	if err != nil {
 		s.writeErrorResponseToStream(responseCodeInvalidRequest, err.Error(), stream)
-		s.cfg.p2p.Peers().Scorers().BadResponsesScorer().Increment(remotePeer)
+		s.downscorePeer(remotePeer, "dataColumnSidecarsByRangeRpcHandlerValidationError")
 		tracing.AnnotateError(span, err)
 		return errors.Wrap(err, "validate data columns by range")
 	}

beacon-chain/sync/rpc_data_column_sidecars_by_root.go

@@ -27,7 +27,7 @@ var (
 )
 
 // dataColumnSidecarByRootRPCHandler handles the data column sidecars by root RPC request.
-// https://github.com/ethereum/consensus-specs/blob/dev/specs/fulu/p2p-interface.md#datacolumnsidecarsbyroot-v1
+// https://github.com/ethereum/consensus-specs/blob/master/specs/fulu/p2p-interface.md#datacolumnsidecarsbyroot-v1
 func (s *Service) dataColumnSidecarByRootRPCHandler(ctx context.Context, msg interface{}, stream libp2pcore.Stream) error {
 	ctx, span := trace.StartSpan(ctx, "sync.dataColumnSidecarByRootRPCHandler")
 	defer span.End()
@@ -42,7 +42,7 @@ func (s *Service) dataColumnSidecarByRootRPCHandler(ctx context.Context, msg int
 	}
 
 	requestedColumnIdents := *ref
-	remotePeerId := stream.Conn().RemotePeer()
+	remotePeer := stream.Conn().RemotePeer()
 
 	ctx, cancel := context.WithTimeout(ctx, ttfbTimeout)
 	defer cancel()
@@ -51,7 +51,7 @@ func (s *Service) dataColumnSidecarByRootRPCHandler(ctx context.Context, msg int
 
 	// Penalize peers that send invalid requests.
 	if err := validateDataColumnsByRootRequest(requestedColumnIdents); err != nil {
-		s.cfg.p2p.Peers().Scorers().BadResponsesScorer().Increment(remotePeerId)
+		s.downscorePeer(remotePeer, "dataColumnSidecarByRootRPCHandlerValidationError")
 		s.writeErrorResponseToStream(responseCodeInvalidRequest, err.Error(), stream)
 		return errors.Wrap(err, "validate data columns by root request")
 	}
@@ -85,7 +85,7 @@ func (s *Service) dataColumnSidecarByRootRPCHandler(ctx context.Context, msg int
 	}
 
 	log := log.WithFields(logrus.Fields{
-		"peer":    remotePeerId,
+		"peer":    remotePeer,
 		"columns": requestedColumnsByRootLog,
 	})