Merge branch 'develop' of https://github.com/prysmaticlabs/geth-sharding into debugE2EFailure

Co-authored-by: Kasey Kirkham <kasey@users.noreply.github.com>

WORKSPACE

@@ -349,9 +349,9 @@ filegroup(
     visibility = ["//visibility:public"],
 )
 """,
-    sha256 = "9f66d8d5644982d3d0d2e3d2b9ebe77a5f96638a5d7fcd715599c32818195cb3",
-    strip_prefix = "holesky-ea39b9006210848e13f28d92e12a30548cecd41d",
-    url = "https://github.com/eth-clients/holesky/archive/ea39b9006210848e13f28d92e12a30548cecd41d.tar.gz",  # 2023-09-21
+    sha256 = "5f4be6fd088683ea9db45c863b9c5a1884422449e5b59fd2d561d3ba0f73ffd9",
+    strip_prefix = "holesky-9d9aabf2d4de51334ee5fed6c79a4d55097d1a43",
+    url = "https://github.com/eth-clients/holesky/archive/9d9aabf2d4de51334ee5fed6c79a4d55097d1a43.tar.gz",  # 2024-01-22
 )
 
 http_archive(

api/headers.go

@@ -7,4 +7,6 @@ const (
 	ConsensusBlockValueHeader     = "Eth-Consensus-Block-Value"
 	JsonMediaType                 = "application/json"
 	OctetStreamMediaType          = "application/octet-stream"
+	EventStreamMediaType          = "text/event-stream"
+	KeepAlive                     = "keep-alive"
 )

beacon-chain/blockchain/BUILD.bazel

@@ -6,6 +6,7 @@ go_library(
         "chain_info.go",
         "chain_info_forkchoice.go",
         "currently_syncing_block.go",
+        "defragment.go",
         "error.go",
         "execution_engine.go",
         "forkchoice_update_execution.go",

beacon-chain/blockchain/chain_info.go

@@ -6,7 +6,10 @@ import (
 	"time"
 
 	"github.com/pkg/errors"
+	"go.opencensus.io/trace"
+
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/core/helpers"
+	f "github.com/prysmaticlabs/prysm/v4/beacon-chain/forkchoice"
 	doublylinkedtree "github.com/prysmaticlabs/prysm/v4/beacon-chain/forkchoice/doubly-linked-tree"
 	forkchoicetypes "github.com/prysmaticlabs/prysm/v4/beacon-chain/forkchoice/types"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/state"
@@ -18,7 +21,6 @@ import (
 	"github.com/prysmaticlabs/prysm/v4/encoding/bytesutil"
 	ethpb "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/v4/time/slots"
-	"go.opencensus.io/trace"
 )
 
 // ChainInfoFetcher defines a common interface for methods in blockchain service which
@@ -334,6 +336,11 @@ func (s *Service) HeadValidatorIndexToPublicKey(_ context.Context, index primiti
 	return v.PublicKey(), nil
 }
 
+// ForkChoicer returns the forkchoice interface.
+func (s *Service) ForkChoicer() f.ForkChoicer {
+	return s.cfg.ForkChoiceStore
+}
+
 // IsOptimistic returns true if the current head is optimistic.
 func (s *Service) IsOptimistic(_ context.Context) (bool, error) {
 	if slots.ToEpoch(s.CurrentSlot()) < params.BeaconConfig().BellatrixForkEpoch {
@@ -549,3 +556,18 @@ func (s *Service) RecentBlockSlot(root [32]byte) (primitives.Slot, error) {
 	defer s.cfg.ForkChoiceStore.RUnlock()
 	return s.cfg.ForkChoiceStore.Slot(root)
 }
+
+// inRegularSync applies the following heuristics to decide if the node is in
+// regular sync mode vs init sync mode using only forkchoice.
+// It checks that the highest received block is behind the current time by at least 2 epochs
+// and that it was imported at least one epoch late if both of these
+// tests pass then the node is in init sync. The caller of this function MUST
+// have a lock on forkchoice
+func (s *Service) inRegularSync() bool {
+	currentSlot := s.CurrentSlot()
+	fc := s.cfg.ForkChoiceStore
+	if currentSlot-fc.HighestReceivedBlockSlot() < 2*params.BeaconConfig().SlotsPerEpoch {
+		return true
+	}
+	return fc.HighestReceivedBlockDelay() < params.BeaconConfig().SlotsPerEpoch
+}

beacon-chain/blockchain/chain_info_test.go

@@ -593,3 +593,26 @@ func TestService_IsFinalized(t *testing.T) {
 	require.Equal(t, true, c.IsFinalized(ctx, br))
 	require.Equal(t, false, c.IsFinalized(ctx, [32]byte{'c'}))
 }
+
+func TestService_inRegularSync(t *testing.T) {
+	ctx := context.Background()
+	c := &Service{cfg: &config{ForkChoiceStore: doublylinkedtree.New()}, head: &head{root: [32]byte{'b'}}}
+	ojc := &ethpb.Checkpoint{Root: params.BeaconConfig().ZeroHash[:]}
+	ofc := &ethpb.Checkpoint{Root: params.BeaconConfig().ZeroHash[:]}
+	st, blkRoot, err := prepareForkchoiceState(ctx, 100, [32]byte{'a'}, [32]byte{}, params.BeaconConfig().ZeroHash, ojc, ofc)
+	require.NoError(t, err)
+	require.NoError(t, c.cfg.ForkChoiceStore.InsertNode(ctx, st, blkRoot))
+	require.Equal(t, false, c.inRegularSync())
+	c.SetGenesisTime(time.Now().Add(time.Second * time.Duration(-1*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot))))
+	st, blkRoot, err = prepareForkchoiceState(ctx, 128, [32]byte{'b'}, [32]byte{'a'}, params.BeaconConfig().ZeroHash, ojc, ofc)
+	require.NoError(t, err)
+	require.NoError(t, c.cfg.ForkChoiceStore.InsertNode(ctx, st, blkRoot))
+	require.Equal(t, false, c.inRegularSync())
+
+	c.SetGenesisTime(time.Now().Add(time.Second * time.Duration(-5*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot))))
+	require.Equal(t, true, c.inRegularSync())
+
+	c.SetGenesisTime(time.Now().Add(time.Second * time.Duration(-1*int64(params.BeaconConfig().SlotsPerEpoch)*int64(params.BeaconConfig().SecondsPerSlot))))
+	c.cfg.ForkChoiceStore.SetGenesisTime(uint64(time.Now().Unix()))
+	require.Equal(t, true, c.inRegularSync())
+}

beacon-chain/blockchain/defragment.go

@@ -0,0 +1,27 @@
+package blockchain
+
+import (
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/state"
+	"github.com/prysmaticlabs/prysm/v4/config/features"
+	"github.com/prysmaticlabs/prysm/v4/time"
+)
+
+var stateDefragmentationTime = promauto.NewSummary(prometheus.SummaryOpts{
+	Name: "head_state_defragmentation_milliseconds",
+	Help: "Milliseconds it takes to defragment the head state",
+})
+
+// This method defragments our state, so that any specific fields which have
+// a higher number of fragmented indexes are reallocated to a new separate slice for
+// that field.
+func (s *Service) defragmentState(st state.BeaconState) {
+	if !features.Get().EnableExperimentalState {
+		return
+	}
+	startTime := time.Now()
+	st.Defragment()
+	elapsedTime := time.Since(startTime)
+	stateDefragmentationTime.Observe(float64(elapsedTime.Milliseconds()))
+}

beacon-chain/blockchain/execution_engine.go

@@ -387,7 +387,10 @@ func (s *Service) removeInvalidBlockAndState(ctx context.Context, blkRoots [][32
 			// This is an irreparable condition, it would me a justified or finalized block has become invalid.
 			return err
 		}
-		// TODO: Remove blob here
+		if err := s.blobStorage.Remove(root); err != nil {
+			// Blobs may not exist for some blocks, leading to deletion failures. Log such errors at debug level.
+			log.WithError(err).Debug("Could not remove blob from blob storage")
+		}
 	}
 	return nil
 }

beacon-chain/blockchain/process_block.go

@@ -6,6 +6,8 @@ import (
 	"time"
 
 	"github.com/pkg/errors"
+	"go.opencensus.io/trace"
+
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/core/blocks"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/core/feed"
 	statefeed "github.com/prysmaticlabs/prysm/v4/beacon-chain/core/feed/state"
@@ -29,7 +31,6 @@ import (
 	"github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1/attestation"
 	"github.com/prysmaticlabs/prysm/v4/runtime/version"
 	"github.com/prysmaticlabs/prysm/v4/time/slots"
-	"go.opencensus.io/trace"
 )
 
 // A custom slot deadline for processing state slots in our cache.
@@ -66,7 +67,10 @@ func (s *Service) postBlockProcess(cfg *postBlockProcessConfig) error {
 	startTime := time.Now()
 	fcuArgs := &fcuConfig{}
 
-	defer s.handleSecondFCUCall(cfg, fcuArgs)
+	if s.inRegularSync() {
+		defer s.handleSecondFCUCall(cfg, fcuArgs)
+	}
+	defer s.sendLightClientFeeds(cfg)
 	defer s.sendStateFeedOnBlock(cfg)
 	defer reportProcessingTime(startTime)
 	defer reportAttestationInclusion(cfg.signed.Block())
@@ -102,6 +106,7 @@ func (s *Service) postBlockProcess(cfg *postBlockProcessConfig) error {
 	if err := s.sendFCU(cfg, fcuArgs); err != nil {
 		return errors.Wrap(err, "could not send FCU to engine")
 	}
+
 	return nil
 }
 
@@ -577,10 +582,15 @@ func (s *Service) lateBlockTasks(ctx context.Context) {
 	if s.CurrentSlot() == s.HeadSlot() {
 		return
 	}
+	s.cfg.ForkChoiceStore.RLock()
+	defer s.cfg.ForkChoiceStore.RUnlock()
+	// return early if we are in init sync
+	if !s.inRegularSync() {
+		return
+	}
 	s.cfg.StateNotifier.StateFeed().Send(&feed.Event{
 		Type: statefeed.MissedSlot,
 	})
-
 	s.headLock.RLock()
 	headRoot := s.headRoot()
 	headState := s.headState(ctx)
@@ -595,18 +605,22 @@ func (s *Service) lateBlockTasks(ctx context.Context) {
 	if err := transition.UpdateNextSlotCache(ctx, lastRoot, lastState); err != nil {
 		log.WithError(err).Debug("could not update next slot state cache")
 	}
-	// handleEpochBoundary requires a forkchoice lock to obtain the target root.
-	s.cfg.ForkChoiceStore.RLock()
 	if err := s.handleEpochBoundary(ctx, currentSlot, headState, headRoot[:]); err != nil {
 		log.WithError(err).Error("lateBlockTasks: could not update epoch boundary caches")
 	}
-	s.cfg.ForkChoiceStore.RUnlock()
 	// return early if we already started building a block for the current
 	// head root
 	_, has := s.cfg.PayloadIDCache.PayloadID(s.CurrentSlot()+1, headRoot)
 	if has {
 		return
 	}
+
+	attribute := s.getPayloadAttribute(ctx, headState, s.CurrentSlot()+1, headRoot[:])
+	// return early if we are not proposing next slot
+	if attribute.IsEmpty() {
+		return
+	}
+
 	s.headLock.RLock()
 	headBlock, err := s.headBlock()
 	if err != nil {
@@ -617,18 +631,12 @@ func (s *Service) lateBlockTasks(ctx context.Context) {
 	s.headLock.RUnlock()
 
 	fcuArgs := &fcuConfig{
-		headState: headState,
-		headRoot:  headRoot,
-		headBlock: headBlock,
+		headState:  headState,
+		headRoot:   headRoot,
+		headBlock:  headBlock,
+		attributes: attribute,
 	}
-	fcuArgs.attributes = s.getPayloadAttribute(ctx, headState, s.CurrentSlot()+1, headRoot[:])
-	// return early if we are not proposing next slot
-	if fcuArgs.attributes.IsEmpty() {
-		return
-	}
-	s.cfg.ForkChoiceStore.RLock()
 	_, err = s.notifyForkchoiceUpdate(ctx, fcuArgs)
-	s.cfg.ForkChoiceStore.RUnlock()
 	if err != nil {
 		log.WithError(err).Debug("could not perform late block tasks: failed to update forkchoice with engine")
 	}

beacon-chain/blockchain/process_block_helpers.go

@@ -7,21 +7,24 @@ import (
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+	"go.opencensus.io/trace"
+
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/core/feed"
 	statefeed "github.com/prysmaticlabs/prysm/v4/beacon-chain/core/feed/state"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/core/transition"
 	doublylinkedtree "github.com/prysmaticlabs/prysm/v4/beacon-chain/forkchoice/doubly-linked-tree"
 	forkchoicetypes "github.com/prysmaticlabs/prysm/v4/beacon-chain/forkchoice/types"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/state"
+	"github.com/prysmaticlabs/prysm/v4/config/features"
 	"github.com/prysmaticlabs/prysm/v4/config/params"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/interfaces"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v4/encoding/bytesutil"
 	mathutil "github.com/prysmaticlabs/prysm/v4/math"
+	ethpbv2 "github.com/prysmaticlabs/prysm/v4/proto/eth/v2"
 	ethpb "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/v4/time/slots"
-	"github.com/sirupsen/logrus"
-	"go.opencensus.io/trace"
 )
 
 // CurrentSlot returns the current slot based on time.
@@ -34,6 +37,9 @@ func (s *Service) getFCUArgs(cfg *postBlockProcessConfig, fcuArgs *fcuConfig) er
 	if err := s.getFCUArgsEarlyBlock(cfg, fcuArgs); err != nil {
 		return err
 	}
+	if !s.inRegularSync() {
+		return nil
+	}
 	slot := cfg.signed.Block().Slot()
 	if slots.WithinVotingWindow(uint64(s.genesisTime.Unix()), slot) {
 		return nil
@@ -106,6 +112,128 @@ func (s *Service) sendStateFeedOnBlock(cfg *postBlockProcessConfig) {
 	})
 }
 
+// sendLightClientFeeds sends the light client feeds when feature flag is enabled.
+func (s *Service) sendLightClientFeeds(cfg *postBlockProcessConfig) {
+	if features.Get().EnableLightClient {
+		if _, err := s.sendLightClientOptimisticUpdate(cfg.ctx, cfg.signed, cfg.postState); err != nil {
+			log.WithError(err).Error("Failed to send light client optimistic update")
+		}
+
+		// Get the finalized checkpoint
+		finalized := s.ForkChoicer().FinalizedCheckpoint()
+
+		// LightClientFinalityUpdate needs super majority
+		s.tryPublishLightClientFinalityUpdate(cfg.ctx, cfg.signed, finalized, cfg.postState)
+	}
+}
+
+func (s *Service) tryPublishLightClientFinalityUpdate(ctx context.Context, signed interfaces.ReadOnlySignedBeaconBlock, finalized *forkchoicetypes.Checkpoint, postState state.BeaconState) {
+	if finalized.Epoch <= s.lastPublishedLightClientEpoch {
+		return
+	}
+
+	config := params.BeaconConfig()
+	if finalized.Epoch < config.AltairForkEpoch {
+		return
+	}
+
+	syncAggregate, err := signed.Block().Body().SyncAggregate()
+	if err != nil || syncAggregate == nil {
+		return
+	}
+
+	// LightClientFinalityUpdate needs super majority
+	if syncAggregate.SyncCommitteeBits.Count()*3 < config.SyncCommitteeSize*2 {
+		return
+	}
+
+	_, err = s.sendLightClientFinalityUpdate(ctx, signed, postState)
+	if err != nil {
+		log.WithError(err).Error("Failed to send light client finality update")
+	} else {
+		s.lastPublishedLightClientEpoch = finalized.Epoch
+	}
+}
+
+// sendLightClientFinalityUpdate sends a light client finality update notification to the state feed.
+func (s *Service) sendLightClientFinalityUpdate(ctx context.Context, signed interfaces.ReadOnlySignedBeaconBlock,
+	postState state.BeaconState) (int, error) {
+	// Get attested state
+	attestedRoot := signed.Block().ParentRoot()
+	attestedState, err := s.cfg.StateGen.StateByRoot(ctx, attestedRoot)
+	if err != nil {
+		return 0, errors.Wrap(err, "could not get attested state")
+	}
+
+	// Get finalized block
+	var finalizedBlock interfaces.ReadOnlySignedBeaconBlock
+	finalizedCheckPoint := attestedState.FinalizedCheckpoint()
+	if finalizedCheckPoint != nil {
+		finalizedRoot := bytesutil.ToBytes32(finalizedCheckPoint.Root)
+		finalizedBlock, err = s.cfg.BeaconDB.Block(ctx, finalizedRoot)
+		if err != nil {
+			finalizedBlock = nil
+		}
+	}
+
+	update, err := NewLightClientFinalityUpdateFromBeaconState(
+		ctx,
+		postState,
+		signed,
+		attestedState,
+		finalizedBlock,
+	)
+
+	if err != nil {
+		return 0, errors.Wrap(err, "could not create light client update")
+	}
+
+	// Return the result
+	result := &ethpbv2.LightClientFinalityUpdateWithVersion{
+		Version: ethpbv2.Version(signed.Version()),
+		Data:    CreateLightClientFinalityUpdate(update),
+	}
+
+	// Send event
+	return s.cfg.StateNotifier.StateFeed().Send(&feed.Event{
+		Type: statefeed.LightClientFinalityUpdate,
+		Data: result,
+	}), nil
+}
+
+// sendLightClientOptimisticUpdate sends a light client optimistic update notification to the state feed.
+func (s *Service) sendLightClientOptimisticUpdate(ctx context.Context, signed interfaces.ReadOnlySignedBeaconBlock,
+	postState state.BeaconState) (int, error) {
+	// Get attested state
+	attestedRoot := signed.Block().ParentRoot()
+	attestedState, err := s.cfg.StateGen.StateByRoot(ctx, attestedRoot)
+	if err != nil {
+		return 0, errors.Wrap(err, "could not get attested state")
+	}
+
+	update, err := NewLightClientOptimisticUpdateFromBeaconState(
+		ctx,
+		postState,
+		signed,
+		attestedState,
+	)
+
+	if err != nil {
+		return 0, errors.Wrap(err, "could not create light client update")
+	}
+
+	// Return the result
+	result := &ethpbv2.LightClientOptimisticUpdateWithVersion{
+		Version: ethpbv2.Version(signed.Version()),
+		Data:    CreateLightClientOptimisticUpdate(update),
+	}
+
+	return s.cfg.StateNotifier.StateFeed().Send(&feed.Event{
+		Type: statefeed.LightClientOptimisticUpdate,
+		Data: result,
+	}), nil
+}
+
 // updateCachesPostBlockProcessing updates the next slot cache and handles the epoch
 // boundary in order to compute the right proposer indices after processing
 // state transition. This function is called on late blocks while still locked,

beacon-chain/blockchain/receive_attestation.go

@@ -150,7 +150,9 @@ func (s *Service) UpdateHead(ctx context.Context, proposingSlot primitives.Slot)
 		headBlock:     headBlock,
 		proposingSlot: proposingSlot,
 	}
-	fcuArgs.attributes = s.getPayloadAttribute(ctx, headState, proposingSlot, newHeadRoot[:])
+	if s.inRegularSync() {
+		fcuArgs.attributes = s.getPayloadAttribute(ctx, headState, proposingSlot, newHeadRoot[:])
+	}
 	if fcuArgs.attributes != nil && s.shouldOverrideFCU(newHeadRoot, proposingSlot) {
 		return
 	}

beacon-chain/blockchain/receive_block.go

@@ -123,6 +123,9 @@ func (s *Service) ReceiveBlock(ctx context.Context, block interfaces.ReadOnlySig
 	}
 	daWaitedTime := time.Since(daStartTime)
 
+	// Defragment the state before continuing block processing.
+	s.defragmentState(postState)
+
 	// The rest of block processing takes a lock on forkchoice.
 	s.cfg.ForkChoiceStore.Lock()
 	defer s.cfg.ForkChoiceStore.Unlock()

beacon-chain/blockchain/service.go

@@ -11,6 +11,8 @@ import (
 	"time"
 
 	"github.com/pkg/errors"
+	"go.opencensus.io/trace"
+
 	"github.com/prysmaticlabs/prysm/v4/async/event"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/blockchain/kzg"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/cache"
@@ -37,34 +39,35 @@ import (
 	"github.com/prysmaticlabs/prysm/v4/config/params"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/blocks"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/interfaces"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v4/encoding/bytesutil"
 	ethpb "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
 	prysmTime "github.com/prysmaticlabs/prysm/v4/time"
 	"github.com/prysmaticlabs/prysm/v4/time/slots"
-	"go.opencensus.io/trace"
 )
 
 // Service represents a service that handles the internal
 // logic of managing the full PoS beacon chain.
 type Service struct {
-	cfg                  *config
-	ctx                  context.Context
-	cancel               context.CancelFunc
-	genesisTime          time.Time
-	head                 *head
-	headLock             sync.RWMutex
-	originBlockRoot      [32]byte // genesis root, or weak subjectivity checkpoint root, depending on how the node is initialized
-	boundaryRoots        [][32]byte
-	checkpointStateCache *cache.CheckpointStateCache
-	initSyncBlocks       map[[32]byte]interfaces.ReadOnlySignedBeaconBlock
-	initSyncBlocksLock   sync.RWMutex
-	wsVerifier           *WeakSubjectivityVerifier
-	clockSetter          startup.ClockSetter
-	clockWaiter          startup.ClockWaiter
-	syncComplete         chan struct{}
-	blobNotifiers        *blobNotifierMap
-	blockBeingSynced     *currentlySyncingBlock
-	blobStorage          *filesystem.BlobStorage
+	cfg                           *config
+	ctx                           context.Context
+	cancel                        context.CancelFunc
+	genesisTime                   time.Time
+	head                          *head
+	headLock                      sync.RWMutex
+	originBlockRoot               [32]byte // genesis root, or weak subjectivity checkpoint root, depending on how the node is initialized
+	boundaryRoots                 [][32]byte
+	checkpointStateCache          *cache.CheckpointStateCache
+	initSyncBlocks                map[[32]byte]interfaces.ReadOnlySignedBeaconBlock
+	initSyncBlocksLock            sync.RWMutex
+	wsVerifier                    *WeakSubjectivityVerifier
+	clockSetter                   startup.ClockSetter
+	clockWaiter                   startup.ClockWaiter
+	syncComplete                  chan struct{}
+	blobNotifiers                 *blobNotifierMap
+	blockBeingSynced              *currentlySyncingBlock
+	blobStorage                   *filesystem.BlobStorage
+	lastPublishedLightClientEpoch primitives.Epoch
 }
 
 // config options for the service.

beacon-chain/blockchain/setup_test.go

@@ -10,6 +10,7 @@ import (
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/cache/depositcache"
 	statefeed "github.com/prysmaticlabs/prysm/v4/beacon-chain/core/feed/state"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/db"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/db/filesystem"
 	testDB "github.com/prysmaticlabs/prysm/v4/beacon-chain/db/testing"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/forkchoice"
 	doublylinkedtree "github.com/prysmaticlabs/prysm/v4/beacon-chain/forkchoice/doubly-linked-tree"
@@ -116,6 +117,7 @@ func minimalTestService(t *testing.T, opts ...Option) (*Service, *testServiceReq
 		WithBLSToExecPool(req.blsPool),
 		WithDepositCache(dc),
 		WithTrackedValidatorsCache(cache.NewTrackedValidatorsCache()),
+		WithBlobStorage(filesystem.NewEphemeralBlobStorage(t)),
 	}
 	// append the variadic opts so they override the defaults by being processed afterwards
 	opts = append(defOpts, opts...)

beacon-chain/core/altair/epoch_precompute.go

@@ -15,11 +15,12 @@ import (
 
 // AttDelta contains rewards and penalties for a single attestation.
 type AttDelta struct {
-	HeadReward    uint64
-	SourceReward  uint64
-	SourcePenalty uint64
-	TargetReward  uint64
-	TargetPenalty uint64
+	HeadReward        uint64
+	SourceReward      uint64
+	SourcePenalty     uint64
+	TargetReward      uint64
+	TargetPenalty     uint64
+	InactivityPenalty uint64
 }
 
 // InitializePrecomputeValidators precomputes individual validator for its attested balances and the total sum of validators attested balances of the epoch.
@@ -251,7 +252,7 @@ func ProcessRewardsAndPenaltiesPrecompute(
 		if err != nil {
 			return nil, err
 		}
-		balances[i] = helpers.DecreaseBalanceWithVal(balances[i], delta.SourcePenalty+delta.TargetPenalty)
+		balances[i] = helpers.DecreaseBalanceWithVal(balances[i], delta.SourcePenalty+delta.TargetPenalty+delta.InactivityPenalty)
 
 		vals[i].AfterEpochTransitionBalance = balances[i]
 	}
@@ -351,7 +352,7 @@ func attestationDelta(
 		if err != nil {
 			return &AttDelta{}, err
 		}
-		attDelta.TargetPenalty += n / inactivityDenominator
+		attDelta.InactivityPenalty = n / inactivityDenominator
 	}
 
 	return attDelta, nil

beacon-chain/core/altair/epoch_precompute_test.go

@@ -220,7 +220,7 @@ func TestAttestationsDelta(t *testing.T) {
 	penalties := make([]uint64, len(deltas))
 	for i, d := range deltas {
 		rewards[i] = d.HeadReward + d.SourceReward + d.TargetReward
-		penalties[i] = d.SourcePenalty + d.TargetPenalty
+		penalties[i] = d.SourcePenalty + d.TargetPenalty + d.InactivityPenalty
 	}
 
 	// Reward amount should increase as validator index increases due to setup.
@@ -258,7 +258,7 @@ func TestAttestationsDeltaBellatrix(t *testing.T) {
 	penalties := make([]uint64, len(deltas))
 	for i, d := range deltas {
 		rewards[i] = d.HeadReward + d.SourceReward + d.TargetReward
-		penalties[i] = d.SourcePenalty + d.TargetPenalty
+		penalties[i] = d.SourcePenalty + d.TargetPenalty + d.InactivityPenalty
 	}
 
 	// Reward amount should increase as validator index increases due to setup.
@@ -306,7 +306,7 @@ func TestProcessRewardsAndPenaltiesPrecompute_Ok(t *testing.T) {
 	penalties := make([]uint64, len(deltas))
 	for i, d := range deltas {
 		rewards[i] = d.HeadReward + d.SourceReward + d.TargetReward
-		penalties[i] = d.SourcePenalty + d.TargetPenalty
+		penalties[i] = d.SourcePenalty + d.TargetPenalty + d.InactivityPenalty
 	}
 	for i := range rewards {
 		wanted[i] += rewards[i]

beacon-chain/core/deneb/upgrade.go

@@ -57,6 +57,10 @@ func UpgradeToDeneb(state state.BeaconState) (state.BeaconState, error) {
 	if err != nil {
 		return nil, err
 	}
+	historicalRoots, err := state.HistoricalRoots()
+	if err != nil {
+		return nil, err
+	}
 
 	s := &ethpb.BeaconStateDeneb{
 		GenesisTime:           state.GenesisTime(),
@@ -70,7 +74,7 @@ func UpgradeToDeneb(state state.BeaconState) (state.BeaconState, error) {
 		LatestBlockHeader:           state.LatestBlockHeader(),
 		BlockRoots:                  state.BlockRoots(),
 		StateRoots:                  state.StateRoots(),
-		HistoricalRoots:             [][]byte{},
+		HistoricalRoots:             historicalRoots,
 		Eth1Data:                    state.Eth1Data(),
 		Eth1DataVotes:               state.Eth1DataVotes(),
 		Eth1DepositIndex:            state.Eth1DepositIndex(),

beacon-chain/core/deneb/upgrade_test.go

@@ -14,6 +14,7 @@ import (
 
 func TestUpgradeToDeneb(t *testing.T) {
 	st, _ := util.DeterministicGenesisStateCapella(t, params.BeaconConfig().MaxValidatorsPerCommittee)
+	require.NoError(t, st.SetHistoricalRoots([][]byte{{1}}))
 	preForkState := st.Copy()
 	mSt, err := deneb.UpgradeToDeneb(st)
 	require.NoError(t, err)
@@ -46,6 +47,12 @@ func TestUpgradeToDeneb(t *testing.T) {
 	require.NoError(t, err)
 	require.DeepSSZEqual(t, make([]uint64, numValidators), s)
 
+	hr1, err := preForkState.HistoricalRoots()
+	require.NoError(t, err)
+	hr2, err := mSt.HistoricalRoots()
+	require.NoError(t, err)
+	require.DeepEqual(t, hr1, hr2)
+
 	f := mSt.Fork()
 	require.DeepSSZEqual(t, &ethpb.Fork{
 		PreviousVersion: st.Fork().CurrentVersion,

beacon-chain/core/feed/state/events.go

@@ -27,6 +27,10 @@ const (
 	NewHead
 	// MissedSlot is sent when we need to notify users that a slot was missed.
 	MissedSlot
+	// LightClientFinalityUpdate event
+	LightClientFinalityUpdate
+	// LightClientOptimisticUpdate event
+	LightClientOptimisticUpdate
 )
 
 // BlockProcessedData is the data sent with BlockProcessed events.

beacon-chain/core/helpers/weak_subjectivity.go

@@ -202,3 +202,14 @@ func ParseWeakSubjectivityInputString(wsCheckpointString string) (*v1alpha1.Chec
 		Root:  bRoot,
 	}, nil
 }
+
+// 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
+// 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
+func MinEpochsForBlockRequests() primitives.Epoch {
+	return params.BeaconConfig().MinValidatorWithdrawabilityDelay +
+		primitives.Epoch(params.BeaconConfig().ChurnLimitQuotient/2)
+}

beacon-chain/core/helpers/weak_subjectivity_test.go

@@ -281,3 +281,19 @@ func genState(t *testing.T, valCount, avgBalance uint64) state.BeaconState {
 
 	return beaconState
 }
+
+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
+	//	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 = (
+	//	    MIN_VALIDATOR_WITHDRAWABILITY_DELAY
+	//	    + MAX_SAFETY_DECAY * CHURN_LIMIT_QUOTIENT // (2 * 100)
+	//	)
+	//
+	//	Where MAX_SAFETY_DECAY = 100 and thus MIN_EPOCHS_FOR_BLOCK_REQUESTS = 33024 (~5 months).
+	require.Equal(t, expected, helpers.MinEpochsForBlockRequests())
+}

beacon-chain/db/errors.go

@@ -22,9 +22,6 @@ var ErrNotFoundOriginBlockRoot = kv.ErrNotFoundOriginBlockRoot
 // ErrNotFoundBackfillBlockRoot wraps ErrNotFound for an error specific to the backfill block root.
 var ErrNotFoundBackfillBlockRoot = kv.ErrNotFoundBackfillBlockRoot
 
-// ErrNotFoundGenesisBlockRoot means no genesis block root was found, indicating the db was not initialized with genesis
-var ErrNotFoundGenesisBlockRoot = kv.ErrNotFoundGenesisBlockRoot
-
 // IsNotFound allows callers to treat errors from a flat-file database, where the file record is missing,
 // as equivalent to db.ErrNotFound.
 func IsNotFound(err error) bool {

beacon-chain/db/filesystem/blob.go

@@ -156,7 +156,7 @@ func (bs *BlobStorage) Save(sidecar blocks.VerifiedROBlob) error {
 	}
 	partialMoved = true
 	blobsWrittenCounter.Inc()
-	blobSaveLatency.Observe(time.Since(startTime).Seconds())
+	blobSaveLatency.Observe(float64(time.Since(startTime).Milliseconds()))
 	return nil
 }
 
@@ -180,11 +180,17 @@ func (bs *BlobStorage) Get(root [32]byte, idx uint64) (blocks.VerifiedROBlob, er
 		return blocks.VerifiedROBlob{}, err
 	}
 	defer func() {
-		blobFetchLatency.Observe(time.Since(startTime).Seconds())
+		blobFetchLatency.Observe(float64(time.Since(startTime).Milliseconds()))
 	}()
 	return verification.BlobSidecarNoop(ro)
 }
 
+// Remove removes all blobs for a given root.
+func (bs *BlobStorage) Remove(root [32]byte) error {
+	rootDir := blobNamer{root: root}.dir()
+	return bs.fs.RemoveAll(rootDir)
+}
+
 // Indices generates a bitmap representing which BlobSidecar.Index values are present on disk for a given root.
 // This value can be compared to the commitments observed in a block to determine which indices need to be found
 // on the network to confirm data availability.

beacon-chain/db/filesystem/blob_test.go

@@ -73,6 +73,21 @@ func TestBlobStorage_SaveBlobData(t *testing.T) {
 		require.NoError(t, err)
 		require.DeepSSZEqual(t, expected, actual)
 	})
+
+	t.Run("round trip write, read and delete", func(t *testing.T) {
+		bs := NewEphemeralBlobStorage(t)
+		err := bs.Save(testSidecars[0])
+		require.NoError(t, err)
+
+		expected := testSidecars[0]
+		actual, err := bs.Get(expected.BlockRoot(), expected.Index)
+		require.NoError(t, err)
+		require.DeepSSZEqual(t, expected, actual)
+
+		require.NoError(t, bs.Remove(expected.BlockRoot()))
+		_, err = bs.Get(expected.BlockRoot(), expected.Index)
+		require.ErrorContains(t, "file does not exist", err)
+	})
 }
 
 // pollUntil polls a condition function until it returns true or a timeout is reached.

beacon-chain/db/filesystem/metrics.go

@@ -6,15 +6,15 @@ import (
 )
 
 var (
-	blobBuckets     = []float64{0.00003, 0.00005, 0.00007, 0.00009, 0.00011, 0.00013, 0.00015}
+	blobBuckets     = []float64{3, 5, 7, 9, 11, 13}
 	blobSaveLatency = promauto.NewHistogram(prometheus.HistogramOpts{
 		Name:    "blob_storage_save_latency",
-		Help:    "Latency of BlobSidecar storage save operations in seconds",
+		Help:    "Latency of BlobSidecar storage save operations in milliseconds",
 		Buckets: blobBuckets,
 	})
 	blobFetchLatency = promauto.NewHistogram(prometheus.HistogramOpts{
 		Name:    "blob_storage_get_latency",
-		Help:    "Latency of BlobSidecar storage get operations in seconds",
+		Help:    "Latency of BlobSidecar storage get operations in milliseconds",
 		Buckets: blobBuckets,
 	})
 	blobsPrunedCounter = promauto.NewCounter(prometheus.CounterOpts{

beacon-chain/db/iface/BUILD.bazel

@@ -13,9 +13,11 @@ go_library(
         "//beacon-chain/db/filters:go_default_library",
         "//beacon-chain/slasher/types:go_default_library",
         "//beacon-chain/state:go_default_library",
+        "//consensus-types/blocks:go_default_library",
         "//consensus-types/interfaces:go_default_library",
         "//consensus-types/primitives:go_default_library",
         "//monitoring/backup:go_default_library",
+        "//proto/dbval:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",
         "@com_github_ethereum_go_ethereum//common:go_default_library",
     ],

beacon-chain/db/iface/interface.go

@@ -11,9 +11,11 @@ import (
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/db/filters"
 	slashertypes "github.com/prysmaticlabs/prysm/v4/beacon-chain/slasher/types"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/state"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/blocks"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/interfaces"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v4/monitoring/backup"
+	"github.com/prysmaticlabs/prysm/v4/proto/dbval"
 	ethpb "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
 )
 
@@ -57,7 +59,7 @@ type ReadOnlyDatabase interface {
 
 	// origin checkpoint sync support
 	OriginCheckpointBlockRoot(ctx context.Context) ([32]byte, error)
-	BackfillBlockRoot(ctx context.Context) ([32]byte, error)
+	BackfillStatus(context.Context) (*dbval.BackfillStatus, error)
 }
 
 // NoHeadAccessDatabase defines a struct without access to chain head data.
@@ -68,6 +70,7 @@ type NoHeadAccessDatabase interface {
 	DeleteBlock(ctx context.Context, root [32]byte) error
 	SaveBlock(ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock) error
 	SaveBlocks(ctx context.Context, blocks []interfaces.ReadOnlySignedBeaconBlock) error
+	SaveROBlocks(ctx context.Context, blks []blocks.ROBlock, cache bool) error
 	SaveGenesisBlockRoot(ctx context.Context, blockRoot [32]byte) error
 	// State related methods.
 	SaveState(ctx context.Context, state state.ReadOnlyBeaconState, blockRoot [32]byte) error
@@ -106,9 +109,10 @@ type HeadAccessDatabase interface {
 	SaveGenesisData(ctx context.Context, state state.BeaconState) error
 	EnsureEmbeddedGenesis(ctx context.Context) error
 
-	// initialization method needed for origin checkpoint sync
+	// Support for checkpoint sync and backfill.
 	SaveOrigin(ctx context.Context, serState, serBlock []byte) error
-	SaveBackfillBlockRoot(ctx context.Context, blockRoot [32]byte) error
+	SaveBackfillStatus(context.Context, *dbval.BackfillStatus) error
+	BackfillFinalizedIndex(ctx context.Context, blocks []blocks.ROBlock, finalizedChildRoot [32]byte) error
 }
 
 // SlasherDatabase interface for persisting data related to detecting slashable offenses on Ethereum.

beacon-chain/db/kv/BUILD.bazel

@@ -4,6 +4,7 @@ go_library(
     name = "go_default_library",
     srcs = [
         "archived_point.go",
+        "backfill.go",
         "backup.go",
         "blocks.go",
         "checkpoint.go",
@@ -48,6 +49,7 @@ go_library(
         "//io/file:go_default_library",
         "//monitoring/progress:go_default_library",
         "//monitoring/tracing:go_default_library",
+        "//proto/dbval:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",
         "//runtime/version:go_default_library",
         "//time:go_default_library",
@@ -73,6 +75,7 @@ go_test(
     name = "go_default_test",
     srcs = [
         "archived_point_test.go",
+        "backfill_test.go",
         "backup_test.go",
         "blocks_test.go",
         "checkpoint_test.go",
@@ -107,6 +110,7 @@ go_test(
         "//consensus-types/interfaces:go_default_library",
         "//consensus-types/primitives:go_default_library",
         "//encoding/bytesutil:go_default_library",
+        "//proto/dbval:go_default_library",
         "//proto/engine/v1:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",
         "//proto/testing:go_default_library",

beacon-chain/db/kv/backfill.go

@@ -0,0 +1,44 @@
+package kv
+
+import (
+	"context"
+
+	"github.com/pkg/errors"
+	"github.com/prysmaticlabs/prysm/v4/proto/dbval"
+	bolt "go.etcd.io/bbolt"
+	"go.opencensus.io/trace"
+	"google.golang.org/protobuf/proto"
+)
+
+// SaveBackfillStatus encodes the given BackfillStatus protobuf struct and writes it to a single key in the db.
+// This value is used by the backfill service to keep track of the range of blocks that need to be synced. It is also used by the
+// code that serves blocks or regenerates states to keep track of what range of blocks are available.
+func (s *Store) SaveBackfillStatus(ctx context.Context, bf *dbval.BackfillStatus) error {
+	_, span := trace.StartSpan(ctx, "BeaconDB.SaveBackfillStatus")
+	defer span.End()
+	bfb, err := proto.Marshal(bf)
+	if err != nil {
+		return err
+	}
+	return s.db.Update(func(tx *bolt.Tx) error {
+		bucket := tx.Bucket(blocksBucket)
+		return bucket.Put(backfillStatusKey, bfb)
+	})
+}
+
+// BackfillStatus retrieves the most recently saved version of the BackfillStatus protobuf struct.
+// This is used to persist information about backfill status across restarts.
+func (s *Store) BackfillStatus(ctx context.Context) (*dbval.BackfillStatus, error) {
+	_, span := trace.StartSpan(ctx, "BeaconDB.BackfillStatus")
+	defer span.End()
+	bf := &dbval.BackfillStatus{}
+	err := s.db.View(func(tx *bolt.Tx) error {
+		bucket := tx.Bucket(blocksBucket)
+		bs := bucket.Get(backfillStatusKey)
+		if len(bs) == 0 {
+			return errors.Wrap(ErrNotFound, "BackfillStatus not found")
+		}
+		return proto.Unmarshal(bs, bf)
+	})
+	return bf, err
+}

beacon-chain/db/kv/backfill_test.go

@@ -0,0 +1,35 @@
+package kv
+
+import (
+	"context"
+	"testing"
+
+	"github.com/prysmaticlabs/prysm/v4/encoding/bytesutil"
+	"github.com/prysmaticlabs/prysm/v4/proto/dbval"
+	"github.com/prysmaticlabs/prysm/v4/testing/require"
+	"google.golang.org/protobuf/proto"
+)
+
+func TestBackfillRoundtrip(t *testing.T) {
+	db := setupDB(t)
+	b := &dbval.BackfillStatus{}
+	b.LowSlot = 23
+	b.LowRoot = bytesutil.PadTo([]byte("low"), 32)
+	b.LowParentRoot = bytesutil.PadTo([]byte("parent"), 32)
+	m, err := proto.Marshal(b)
+	require.NoError(t, err)
+	ub := &dbval.BackfillStatus{}
+	require.NoError(t, proto.Unmarshal(m, ub))
+	require.Equal(t, b.LowSlot, ub.LowSlot)
+	require.DeepEqual(t, b.LowRoot, ub.LowRoot)
+	require.DeepEqual(t, b.LowParentRoot, ub.LowParentRoot)
+
+	ctx := context.Background()
+	require.NoError(t, db.SaveBackfillStatus(ctx, b))
+	dbub, err := db.BackfillStatus(ctx)
+	require.NoError(t, err)
+
+	require.Equal(t, b.LowSlot, dbub.LowSlot)
+	require.DeepEqual(t, b.LowRoot, dbub.LowRoot)
+	require.DeepEqual(t, b.LowParentRoot, dbub.LowParentRoot)
+}

beacon-chain/db/kv/blocks.go

@@ -70,25 +70,6 @@ func (s *Store) OriginCheckpointBlockRoot(ctx context.Context) ([32]byte, error)
 	return root, err
 }
 
-// BackfillBlockRoot keeps track of the highest block available before the OriginCheckpointBlockRoot
-func (s *Store) BackfillBlockRoot(ctx context.Context) ([32]byte, error) {
-	_, span := trace.StartSpan(ctx, "BeaconDB.BackfillBlockRoot")
-	defer span.End()
-
-	var root [32]byte
-	err := s.db.View(func(tx *bolt.Tx) error {
-		bkt := tx.Bucket(blocksBucket)
-		rootSlice := bkt.Get(backfillBlockRootKey)
-		if len(rootSlice) == 0 {
-			return ErrNotFoundBackfillBlockRoot
-		}
-		root = bytesutil.ToBytes32(rootSlice)
-		return nil
-	})
-
-	return root, err
-}
-
 // HeadBlock returns the latest canonical block in the Ethereum Beacon Chain.
 func (s *Store) HeadBlock(ctx context.Context) (interfaces.ReadOnlySignedBeaconBlock, error) {
 	ctx, span := trace.StartSpan(ctx, "BeaconDB.HeadBlock")
@@ -292,55 +273,95 @@ func (s *Store) SaveBlocks(ctx context.Context, blks []interfaces.ReadOnlySigned
 	ctx, span := trace.StartSpan(ctx, "BeaconDB.SaveBlocks")
 	defer span.End()
 
-	// Performing marshaling, hashing, and indexing outside the bolt transaction
-	// to minimize the time we hold the DB lock.
-	blockRoots := make([][]byte, len(blks))
-	encodedBlocks := make([][]byte, len(blks))
-	indicesForBlocks := make([]map[string][]byte, len(blks))
-	for i, blk := range blks {
-		blockRoot, err := blk.Block().HashTreeRoot()
+	robs := make([]blocks.ROBlock, len(blks))
+	for i := range blks {
+		rb, err := blocks.NewROBlock(blks[i])
 		if err != nil {
-			return err
+			return errors.Wrapf(err, "failed to make an ROBlock for a block in SaveBlocks")
 		}
-		enc, err := s.marshalBlock(ctx, blk)
-		if err != nil {
-			return err
-		}
-		blockRoots[i] = blockRoot[:]
-		encodedBlocks[i] = enc
-		indicesByBucket := createBlockIndicesFromBlock(ctx, blk.Block())
-		indicesForBlocks[i] = indicesByBucket
+		robs[i] = rb
 	}
-	saveBlinded, err := s.shouldSaveBlinded(ctx)
+	return s.SaveROBlocks(ctx, robs, true)
+}
+
+type blockBatchEntry struct {
+	root    []byte
+	block   interfaces.ReadOnlySignedBeaconBlock
+	enc     []byte
+	updated bool
+	indices map[string][]byte
+}
+
+func prepareBlockBatch(blks []blocks.ROBlock, shouldBlind bool) ([]blockBatchEntry, error) {
+	batch := make([]blockBatchEntry, len(blks))
+	for i := range blks {
+		batch[i].root, batch[i].block = blks[i].RootSlice(), blks[i].ReadOnlySignedBeaconBlock
+		batch[i].indices = blockIndices(batch[i].block.Block().Slot(), batch[i].block.Block().ParentRoot())
+		if shouldBlind {
+			blinded, err := batch[i].block.ToBlinded()
+			if err != nil {
+				if !errors.Is(err, blocks.ErrUnsupportedVersion) {
+					return nil, errors.Wrapf(err, "could not convert block to blinded format for root %#x", batch[i].root)
+				}
+				// Pre-deneb blocks give ErrUnsupportedVersion; use the full block already in the batch entry.
+			} else {
+				batch[i].block = blinded
+			}
+		}
+		enc, err := encodeBlock(batch[i].block)
+		if err != nil {
+			return nil, errors.Wrapf(err, "failed to encode block for root %#x", batch[i].root)
+		}
+		batch[i].enc = enc
+	}
+	return batch, nil
+}
+
+func (s *Store) SaveROBlocks(ctx context.Context, blks []blocks.ROBlock, cache bool) error {
+	shouldBlind, err := s.shouldSaveBlinded(ctx)
 	if err != nil {
 		return err
 	}
-	return s.db.Update(func(tx *bolt.Tx) error {
+	// Precompute expensive values outside the db transaction.
+	batch, err := prepareBlockBatch(blks, shouldBlind)
+	if err != nil {
+		return errors.Wrap(err, "failed to encode all blocks in batch for saving to the db")
+	}
+	err = s.db.Update(func(tx *bolt.Tx) error {
 		bkt := tx.Bucket(blocksBucket)
-		for i, blk := range blks {
-			if existingBlock := bkt.Get(blockRoots[i]); existingBlock != nil {
+		for i := range batch {
+			if exists := bkt.Get(batch[i].root); exists != nil {
 				continue
 			}
-			if err := updateValueForIndices(ctx, indicesForBlocks[i], blockRoots[i], tx); err != nil {
-				return errors.Wrap(err, "could not update DB indices")
+			if err := bkt.Put(batch[i].root, batch[i].enc); err != nil {
+				return errors.Wrapf(err, "could write block to db with root %#x", batch[i].root)
 			}
-			if saveBlinded {
-				blindedBlock, err := blk.ToBlinded()
-				if err != nil {
-					if !errors.Is(err, blocks.ErrUnsupportedVersion) {
-						return err
-					}
-				} else {
-					blk = blindedBlock
-				}
-			}
-			s.blockCache.Set(string(blockRoots[i]), blk, int64(len(encodedBlocks[i])))
-			if err := bkt.Put(blockRoots[i], encodedBlocks[i]); err != nil {
-				return err
+			if err := updateValueForIndices(ctx, batch[i].indices, batch[i].root, tx); err != nil {
+				return errors.Wrapf(err, "could not update DB indices for root %#x", batch[i].root)
 			}
+			batch[i].updated = true
 		}
 		return nil
 	})
+	if !cache {
+		return err
+	}
+	for i := range batch {
+		if batch[i].updated {
+			s.blockCache.Set(string(batch[i].root), batch[i].block, int64(len(batch[i].enc)))
+		}
+	}
+	return err
+}
+
+// blockIndices takes in a beacon block and returns
+// a map of bolt DB index buckets corresponding to each particular key for indices for
+// data, such as (shard indices bucket -> shard 5).
+func blockIndices(slot primitives.Slot, parentRoot [32]byte) map[string][]byte {
+	return map[string][]byte{
+		string(blockSlotIndicesBucket):       bytesutil.SlotToBytesBigEndian(slot),
+		string(blockParentRootIndicesBucket): parentRoot[:],
+	}
 }
 
 // SaveHeadBlockRoot to the db.
@@ -417,17 +438,6 @@ func (s *Store) SaveOriginCheckpointBlockRoot(ctx context.Context, blockRoot [32
 	})
 }
 
-// SaveBackfillBlockRoot is used to keep track of the most recently backfilled block root when
-// the node was initialized via checkpoint sync.
-func (s *Store) SaveBackfillBlockRoot(ctx context.Context, blockRoot [32]byte) error {
-	_, span := trace.StartSpan(ctx, "BeaconDB.SaveBackfillBlockRoot")
-	defer span.End()
-	return s.db.Update(func(tx *bolt.Tx) error {
-		bucket := tx.Bucket(blocksBucket)
-		return bucket.Put(backfillBlockRootKey, blockRoot[:])
-	})
-}
-
 // HighestRootsBelowSlot returns roots from the database slot index from the highest slot below the input slot.
 // The slot value at the beginning of the return list is the slot where the roots were found. This is helpful so that
 // calling code can make decisions based on the slot without resolving the blocks to discover their slot (for instance
@@ -726,31 +736,6 @@ func blockRootsBySlot(ctx context.Context, tx *bolt.Tx, slot primitives.Slot) ([
 	return [][32]byte{}, nil
 }
 
-// createBlockIndicesFromBlock takes in a beacon block and returns
-// a map of bolt DB index buckets corresponding to each particular key for indices for
-// data, such as (shard indices bucket -> shard 5).
-func createBlockIndicesFromBlock(ctx context.Context, block interfaces.ReadOnlyBeaconBlock) map[string][]byte {
-	_, span := trace.StartSpan(ctx, "BeaconDB.createBlockIndicesFromBlock")
-	defer span.End()
-	indicesByBucket := make(map[string][]byte)
-	// Every index has a unique bucket for fast, binary-search
-	// range scans for filtering across keys.
-	buckets := [][]byte{
-		blockSlotIndicesBucket,
-	}
-	indices := [][]byte{
-		bytesutil.SlotToBytesBigEndian(block.Slot()),
-	}
-	buckets = append(buckets, blockParentRootIndicesBucket)
-	parentRoot := block.ParentRoot()
-	indices = append(indices, parentRoot[:])
-
-	for i := 0; i < len(buckets); i++ {
-		indicesByBucket[string(buckets[i])] = indices[i]
-	}
-	return indicesByBucket
-}
-
 // createBlockFiltersFromIndices takes in filter criteria and returns
 // a map with a single key-value pair: "block-parent-root-indices” -> parentRoot (array of bytes).
 //
@@ -838,74 +823,44 @@ func unmarshalBlock(_ context.Context, enc []byte) (interfaces.ReadOnlySignedBea
 	return blocks.NewSignedBeaconBlock(rawBlock)
 }
 
-func (s *Store) marshalBlock(
-	ctx context.Context,
-	blk interfaces.ReadOnlySignedBeaconBlock,
-) ([]byte, error) {
-	shouldBlind, err := s.shouldSaveBlinded(ctx)
+func encodeBlock(blk interfaces.ReadOnlySignedBeaconBlock) ([]byte, error) {
+	key, err := keyForBlock(blk)
 	if err != nil {
-		return nil, err
+		return nil, errors.Wrap(err, "could not determine version encoding key for block")
 	}
-	if shouldBlind {
-		return marshalBlockBlinded(ctx, blk)
+	enc, err := blk.MarshalSSZ()
+	if err != nil {
+		return nil, errors.Wrap(err, "could not marshal block")
 	}
-	return marshalBlockFull(ctx, blk)
+	dbfmt := make([]byte, len(key)+len(enc))
+	if len(key) > 0 {
+		copy(dbfmt, key)
+	}
+	copy(dbfmt[len(key):], enc)
+	return snappy.Encode(nil, dbfmt), nil
 }
 
-// Encodes a full beacon block to the DB with its associated key.
-func marshalBlockFull(
-	_ context.Context,
-	blk interfaces.ReadOnlySignedBeaconBlock,
-) ([]byte, error) {
-	var encodedBlock []byte
-	var err error
-	encodedBlock, err = blk.MarshalSSZ()
-	if err != nil {
-		return nil, err
-	}
+func keyForBlock(blk interfaces.ReadOnlySignedBeaconBlock) ([]byte, error) {
 	switch blk.Version() {
 	case version.Deneb:
-		return snappy.Encode(nil, append(denebKey, encodedBlock...)), nil
-	case version.Capella:
-		return snappy.Encode(nil, append(capellaKey, encodedBlock...)), nil
-	case version.Bellatrix:
-		return snappy.Encode(nil, append(bellatrixKey, encodedBlock...)), nil
-	case version.Altair:
-		return snappy.Encode(nil, append(altairKey, encodedBlock...)), nil
-	case version.Phase0:
-		return snappy.Encode(nil, encodedBlock), nil
-	default:
-		return nil, errors.New("unknown block version")
-	}
-}
-
-// Encodes a blinded beacon block with its associated key.
-// If the block does not support blinding, we then encode it as a full
-// block with its associated key by calling marshalBlockFull.
-func marshalBlockBlinded(
-	ctx context.Context,
-	blk interfaces.ReadOnlySignedBeaconBlock,
-) ([]byte, error) {
-	blindedBlock, err := blk.ToBlinded()
-	if err != nil {
-		switch {
-		case errors.Is(err, blocks.ErrUnsupportedVersion):
-			return marshalBlockFull(ctx, blk)
-		default:
-			return nil, errors.Wrap(err, "could not convert block to blinded format")
+		if blk.IsBlinded() {
+			return denebBlindKey, nil
 		}
-	}
-	encodedBlock, err := blindedBlock.MarshalSSZ()
-	if err != nil {
-		return nil, errors.Wrap(err, "could not marshal blinded block")
-	}
-	switch blk.Version() {
-	case version.Deneb:
-		return snappy.Encode(nil, append(denebBlindKey, encodedBlock...)), nil
+		return denebKey, nil
 	case version.Capella:
-		return snappy.Encode(nil, append(capellaBlindKey, encodedBlock...)), nil
+		if blk.IsBlinded() {
+			return capellaBlindKey, nil
+		}
+		return capellaKey, nil
 	case version.Bellatrix:
-		return snappy.Encode(nil, append(bellatrixBlindKey, encodedBlock...)), nil
+		if blk.IsBlinded() {
+			return bellatrixBlindKey, nil
+		}
+		return bellatrixKey, nil
+	case version.Altair:
+		return altairKey, nil
+	case version.Phase0:
+		return nil, nil
 	default:
 		return nil, fmt.Errorf("unsupported block version: %v", blk.Version())
 	}

beacon-chain/db/kv/blocks_test.go

@@ -126,23 +126,6 @@ var blockTests = []struct {
 	},
 }
 
-func TestStore_SaveBackfillBlockRoot(t *testing.T) {
-	db := setupDB(t)
-	ctx := context.Background()
-
-	_, err := db.BackfillBlockRoot(ctx)
-	require.ErrorIs(t, err, ErrNotFoundBackfillBlockRoot)
-
-	var expected [32]byte
-	copy(expected[:], []byte{0x23})
-	err = db.SaveBackfillBlockRoot(ctx, expected)
-	require.NoError(t, err)
-	actual, err := db.BackfillBlockRoot(ctx)
-	require.NoError(t, err)
-	require.Equal(t, expected, actual)
-
-}
-
 func TestStore_SaveBlock_NoDuplicates(t *testing.T) {
 	BlockCacheSize = 1
 	slot := primitives.Slot(20)

beacon-chain/db/kv/error.go

@@ -21,3 +21,8 @@ var ErrNotFoundBackfillBlockRoot = errors.Wrap(ErrNotFound, "BackfillBlockRoot")
 
 // ErrNotFoundFeeRecipient is a not found error specifically for the fee recipient getter
 var ErrNotFoundFeeRecipient = errors.Wrap(ErrNotFound, "fee recipient")
+
+var errEmptyBlockSlice = errors.New("[]blocks.ROBlock is empty")
+var errIncorrectBlockParent = errors.New("unexpected missing or forked blocks in a []ROBlock")
+var errFinalizedChildNotFound = errors.New("unable to find finalized root descending from backfill batch")
+var errNotConnectedToFinalized = errors.New("unable to finalize backfill blocks, finalized parent_root does not match")

beacon-chain/db/kv/finalized_block_roots.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"context"
 
+	"github.com/pkg/errors"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/db/filters"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/blocks"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/interfaces"
@@ -163,6 +164,83 @@ func (s *Store) updateFinalizedBlockRoots(ctx context.Context, tx *bolt.Tx, chec
 	return bkt.Put(previousFinalizedCheckpointKey, enc)
 }
 
+// BackfillFinalizedIndex updates the finalized index for a contiguous chain of blocks that are the ancestors of the
+// given finalized child root. This is needed to update the finalized index during backfill, because the usual
+// updateFinalizedBlockRoots has assumptions that are incompatible with backfill processing.
+func (s *Store) BackfillFinalizedIndex(ctx context.Context, blocks []blocks.ROBlock, finalizedChildRoot [32]byte) error {
+	ctx, span := trace.StartSpan(ctx, "BeaconDB.BackfillFinalizedIndex")
+	defer span.End()
+	if len(blocks) == 0 {
+		return errEmptyBlockSlice
+	}
+
+	fbrs := make([]*ethpb.FinalizedBlockRootContainer, len(blocks))
+	encs := make([][]byte, len(blocks))
+	for i := range blocks {
+		pr := blocks[i].Block().ParentRoot()
+		fbrs[i] = &ethpb.FinalizedBlockRootContainer{
+			ParentRoot: pr[:],
+			// ChildRoot: will be filled in on the next iteration when we look at the descendent block.
+		}
+		if i == 0 {
+			continue
+		}
+		if blocks[i-1].Root() != blocks[i].Block().ParentRoot() {
+			return errors.Wrapf(errIncorrectBlockParent, "previous root=%#x, slot=%d; child parent_root=%#x, root=%#x, slot=%d",
+				blocks[i-1].Root(), blocks[i-1].Block().Slot(), blocks[i].Block().ParentRoot(), blocks[i].Root(), blocks[i].Block().Slot())
+		}
+
+		// We know the previous index is the parent of this one thanks to the assertion above,
+		// so we can set the ChildRoot of the previous value to the root of the current value.
+		fbrs[i-1].ChildRoot = blocks[i].RootSlice()
+		// Now that the value for fbrs[i-1] is complete, perform encoding here to minimize time in Update,
+		// which holds the global db lock.
+		penc, err := encode(ctx, fbrs[i-1])
+		if err != nil {
+			tracing.AnnotateError(span, err)
+			return err
+		}
+		encs[i-1] = penc
+
+		// The final element is the parent of finalizedChildRoot. This is checked inside the db transaction using
+		// the parent_root value stored in the index data for finalizedChildRoot.
+		if i == len(blocks)-1 {
+			fbrs[i].ChildRoot = finalizedChildRoot[:]
+			// Final element is complete, so it is pre-encoded like the others.
+			enc, err := encode(ctx, fbrs[i])
+			if err != nil {
+				tracing.AnnotateError(span, err)
+				return err
+			}
+			encs[i] = enc
+		}
+	}
+
+	return s.db.Update(func(tx *bolt.Tx) error {
+		bkt := tx.Bucket(finalizedBlockRootsIndexBucket)
+		child := bkt.Get(finalizedChildRoot[:])
+		if len(child) == 0 {
+			return errFinalizedChildNotFound
+		}
+		fcc := &ethpb.FinalizedBlockRootContainer{}
+		if err := decode(ctx, child, fcc); err != nil {
+			return errors.Wrapf(err, "unable to decode finalized block root container for root=%#x", finalizedChildRoot)
+		}
+		// Ensure that the existing finalized chain descends from the new segment.
+		if !bytes.Equal(fcc.ParentRoot, blocks[len(blocks)-1].RootSlice()) {
+			return errors.Wrapf(errNotConnectedToFinalized, "finalized block root container for root=%#x has parent_root=%#x, not %#x",
+				finalizedChildRoot, fcc.ParentRoot, blocks[len(blocks)-1].RootSlice())
+		}
+		// Update the finalized index with entries for each block in the new segment.
+		for i := range fbrs {
+			if err := bkt.Put(blocks[i].RootSlice(), encs[i]); err != nil {
+				return err
+			}
+		}
+		return nil
+	})
+}
+
 // IsFinalizedBlock returns true if the block root is present in the finalized block root index.
 // A beacon block root contained exists in this index if it is considered finalized and canonical.
 // Note: beacon blocks from the latest finalized epoch return true, whether or not they are

beacon-chain/db/kv/finalized_block_roots_test.go

@@ -1,6 +1,7 @@
 package kv
 
 import (
+	"bytes"
 	"context"
 	"testing"
 
@@ -14,6 +15,7 @@ import (
 	"github.com/prysmaticlabs/prysm/v4/testing/assert"
 	"github.com/prysmaticlabs/prysm/v4/testing/require"
 	"github.com/prysmaticlabs/prysm/v4/testing/util"
+	bolt "go.etcd.io/bbolt"
 )
 
 var genesisBlockRoot = bytesutil.ToBytes32([]byte{'G', 'E', 'N', 'E', 'S', 'I', 'S'})
@@ -234,3 +236,64 @@ func makeBlocksAltair(t *testing.T, startIdx, num uint64, previousRoot [32]byte)
 	}
 	return ifaceBlocks
 }
+
+func TestStore_BackfillFinalizedIndex(t *testing.T) {
+	db := setupDB(t)
+	ctx := context.Background()
+	require.ErrorIs(t, db.BackfillFinalizedIndex(ctx, []consensusblocks.ROBlock{}, [32]byte{}), errEmptyBlockSlice)
+	blks, err := consensusblocks.NewROBlockSlice(makeBlocks(t, 0, 66, [32]byte{}))
+	require.NoError(t, err)
+
+	// set up existing finalized block
+	ebpr := blks[64].Block().ParentRoot()
+	ebr := blks[64].Root()
+	chldr := blks[65].Root()
+	ebf := &ethpb.FinalizedBlockRootContainer{
+		ParentRoot: ebpr[:],
+		ChildRoot:  chldr[:],
+	}
+	disjoint := []consensusblocks.ROBlock{
+		blks[0],
+		blks[2],
+	}
+	enc, err := encode(ctx, ebf)
+	require.NoError(t, err)
+	err = db.db.Update(func(tx *bolt.Tx) error {
+		bkt := tx.Bucket(finalizedBlockRootsIndexBucket)
+		return bkt.Put(ebr[:], enc)
+	})
+
+	// reslice to remove the existing blocks
+	blks = blks[0:64]
+	// check the other error conditions with a descendent root that really doesn't exist
+	require.NoError(t, err)
+	require.ErrorIs(t, db.BackfillFinalizedIndex(ctx, disjoint, [32]byte{}), errIncorrectBlockParent)
+	require.NoError(t, err)
+	require.ErrorIs(t, errFinalizedChildNotFound, db.BackfillFinalizedIndex(ctx, blks, [32]byte{}))
+
+	// use the real root so that it succeeds
+	require.NoError(t, db.BackfillFinalizedIndex(ctx, blks, ebr))
+	for i := range blks {
+		require.NoError(t, db.db.View(func(tx *bolt.Tx) error {
+			bkt := tx.Bucket(finalizedBlockRootsIndexBucket)
+			encfr := bkt.Get(blks[i].RootSlice())
+			require.Equal(t, true, len(encfr) > 0)
+			fr := &ethpb.FinalizedBlockRootContainer{}
+			require.NoError(t, decode(ctx, encfr, fr))
+			require.Equal(t, 32, len(fr.ParentRoot))
+			require.Equal(t, 32, len(fr.ChildRoot))
+			pr := blks[i].Block().ParentRoot()
+			require.Equal(t, true, bytes.Equal(fr.ParentRoot, pr[:]))
+			if i > 0 {
+				require.Equal(t, true, bytes.Equal(fr.ParentRoot, blks[i-1].RootSlice()))
+			}
+			if i < len(blks)-1 {
+				require.DeepEqual(t, fr.ChildRoot, blks[i+1].RootSlice())
+			}
+			if i == len(blks)-1 {
+				require.DeepEqual(t, fr.ChildRoot, ebr[:])
+			}
+			return nil
+		}))
+	}
+}

beacon-chain/db/kv/kv_test.go

@@ -1,6 +1,7 @@
 package kv
 
 import (
+	"bytes"
 	"context"
 	"fmt"
 	"testing"
@@ -116,13 +117,25 @@ func Test_setupBlockStorageType(t *testing.T) {
 		root, err = wrappedBlock.Block().HashTreeRoot()
 		require.NoError(t, err)
 		require.NoError(t, store.SaveBlock(ctx, wrappedBlock))
-		retrievedBlk, err = store.Block(ctx, root)
-		require.NoError(t, err)
-
-		require.Equal(t, true, retrievedBlk.IsBlinded())
 		wrappedBlinded, err := wrappedBlock.ToBlinded()
 		require.NoError(t, err)
-		require.DeepEqual(t, wrappedBlinded, retrievedBlk)
+
+		retrievedBlk, err = store.Block(ctx, root)
+		require.NoError(t, err)
+		require.Equal(t, true, retrievedBlk.IsBlinded())
+
+		// Compare retrieved value by root, and marshaled bytes.
+		mSrc, err := wrappedBlinded.MarshalSSZ()
+		require.NoError(t, err)
+		mTgt, err := retrievedBlk.MarshalSSZ()
+		require.NoError(t, err)
+		require.Equal(t, true, bytes.Equal(mSrc, mTgt))
+
+		rSrc, err := wrappedBlinded.Block().HashTreeRoot()
+		require.NoError(t, err)
+		rTgt, err := retrievedBlk.Block().HashTreeRoot()
+		require.NoError(t, err)
+		require.Equal(t, rSrc, rTgt)
 	})
 	t.Run("existing database with full blocks type should continue storing full blocks", func(t *testing.T) {
 		store := setupDB(t)
@@ -155,10 +168,21 @@ func Test_setupBlockStorageType(t *testing.T) {
 		root, err = wrappedBlock.Block().HashTreeRoot()
 		require.NoError(t, err)
 		require.NoError(t, store.SaveBlock(ctx, wrappedBlock))
+
 		retrievedBlk, err = store.Block(ctx, root)
 		require.NoError(t, err)
 		require.Equal(t, false, retrievedBlk.IsBlinded())
-		require.DeepEqual(t, wrappedBlock, retrievedBlk)
+
+		// Compare retrieved value by root, and marshaled bytes.
+		mSrc, err := wrappedBlock.MarshalSSZ()
+		require.NoError(t, err)
+		mTgt, err := retrievedBlk.MarshalSSZ()
+		require.NoError(t, err)
+		require.Equal(t, true, bytes.Equal(mSrc, mTgt))
+
+		rTgt, err := retrievedBlk.Block().HashTreeRoot()
+		require.NoError(t, err)
+		require.Equal(t, root, rTgt)
 	})
 	t.Run("existing database with blinded blocks type should error if user enables full blocks feature flag", func(t *testing.T) {
 		store := setupDB(t)

beacon-chain/db/kv/schema.go

@@ -61,8 +61,8 @@ var (
 
 	// block root included in the beacon state used by weak subjectivity initial sync
 	originCheckpointBlockRootKey = []byte("origin-checkpoint-block-root")
-	// block root tracking the progress of backfill, or pointing at genesis if backfill has not been initiated
-	backfillBlockRootKey = []byte("backfill-block-root")
+	// tracking data about an ongoing backfill
+	backfillStatusKey = []byte("backfill-status")
 
 	// Deprecated: This index key was migrated in PR 6461. Do not use, except for migrations.
 	lastArchivedIndexKey = []byte("last-archived")

beacon-chain/db/kv/wss.go

@@ -8,6 +8,7 @@ import (
 	"github.com/prysmaticlabs/prysm/v4/config/params"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v4/encoding/ssz/detect"
+	"github.com/prysmaticlabs/prysm/v4/proto/dbval"
 	ethpb "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/v4/runtime/version"
 )
@@ -17,18 +18,6 @@ import (
 // syncing, using the provided values as their point of origin. This is an alternative
 // to syncing from genesis, and should only be run on an empty database.
 func (s *Store) SaveOrigin(ctx context.Context, serState, serBlock []byte) error {
-	genesisRoot, err := s.GenesisBlockRoot(ctx)
-	if err != nil {
-		if errors.Is(err, ErrNotFoundGenesisBlockRoot) {
-			return errors.Wrap(err, "genesis block root not found: genesis must be provided for checkpoint sync")
-		}
-		return errors.Wrap(err, "genesis block root query error: checkpoint sync must verify genesis to proceed")
-	}
-	err = s.SaveBackfillBlockRoot(ctx, genesisRoot)
-	if err != nil {
-		return errors.Wrap(err, "unable to save genesis root as initial backfill starting point for checkpoint sync")
-	}
-
 	cf, err := detect.FromState(serState)
 	if err != nil {
 		return errors.Wrap(err, "could not sniff config+fork for origin state bytes")
@@ -50,11 +39,24 @@ func (s *Store) SaveOrigin(ctx context.Context, serState, serBlock []byte) error
 	}
 	blk := wblk.Block()
 
-	// save block
 	blockRoot, err := blk.HashTreeRoot()
 	if err != nil {
 		return errors.Wrap(err, "could not compute HashTreeRoot of checkpoint block")
 	}
+
+	pr := blk.ParentRoot()
+	bf := &dbval.BackfillStatus{
+		LowSlot:       uint64(wblk.Block().Slot()),
+		LowRoot:       blockRoot[:],
+		LowParentRoot: pr[:],
+		OriginRoot:    blockRoot[:],
+		OriginSlot:    uint64(wblk.Block().Slot()),
+	}
+
+	if err = s.SaveBackfillStatus(ctx, bf); err != nil {
+		return errors.Wrap(err, "unable to save backfill status data to db for checkpoint sync")
+	}
+
 	log.Infof("saving checkpoint block to db, w/ root=%#x", blockRoot)
 	if err := s.SaveBlock(ctx, wblk); err != nil {
 		return errors.Wrap(err, "could not save checkpoint block")

beacon-chain/execution/log.go

@@ -2,4 +2,4 @@ package execution
 
 import "github.com/sirupsen/logrus"
 
-var log = logrus.WithField("prefix", "powchain")
+var log = logrus.WithField("prefix", "execution")

beacon-chain/forkchoice/doubly-linked-tree/store.go

@@ -240,6 +240,20 @@ func (f *ForkChoice) HighestReceivedBlockSlot() primitives.Slot {
 	return f.store.highestReceivedNode.slot
 }
 
+// HighestReceivedBlockSlotDelay returns the number of slots that the highest
+// received block was late when receiving it
+func (f *ForkChoice) HighestReceivedBlockDelay() primitives.Slot {
+	n := f.store.highestReceivedNode
+	if n == nil {
+		return 0
+	}
+	secs, err := slots.SecondsSinceSlotStart(n.slot, f.store.genesisTime, n.timestamp)
+	if err != nil {
+		return 0
+	}
+	return primitives.Slot(secs / params.BeaconConfig().SecondsPerSlot)
+}
+
 // ReceivedBlocksLastEpoch returns the number of blocks received in the last epoch
 func (f *ForkChoice) ReceivedBlocksLastEpoch() (uint64, error) {
 	count := uint64(0)

beacon-chain/forkchoice/doubly-linked-tree/store_test.go

@@ -333,26 +333,29 @@ func TestForkChoice_ReceivedBlocksLastEpoch(t *testing.T) {
 	require.NoError(t, err)
 	require.Equal(t, uint64(1), count)
 	require.Equal(t, primitives.Slot(1), f.HighestReceivedBlockSlot())
+	require.Equal(t, primitives.Slot(0), f.HighestReceivedBlockDelay())
 
 	// 64
 	// Received block last epoch is 1
 	_, err = s.insert(context.Background(), 64, [32]byte{'A'}, b, b, 1, 1)
 	require.NoError(t, err)
-	s.genesisTime = uint64(time.Now().Add(time.Duration(-64*int64(params.BeaconConfig().SecondsPerSlot)) * time.Second).Unix())
+	s.genesisTime = uint64(time.Now().Add(time.Duration((-64*int64(params.BeaconConfig().SecondsPerSlot))-1) * time.Second).Unix())
 	count, err = f.ReceivedBlocksLastEpoch()
 	require.NoError(t, err)
 	require.Equal(t, uint64(1), count)
 	require.Equal(t, primitives.Slot(64), f.HighestReceivedBlockSlot())
+	require.Equal(t, primitives.Slot(0), f.HighestReceivedBlockDelay())
 
 	// 64 65
 	// Received block last epoch is 2
 	_, err = s.insert(context.Background(), 65, [32]byte{'B'}, b, b, 1, 1)
 	require.NoError(t, err)
-	s.genesisTime = uint64(time.Now().Add(time.Duration(-65*int64(params.BeaconConfig().SecondsPerSlot)) * time.Second).Unix())
+	s.genesisTime = uint64(time.Now().Add(time.Duration(-66*int64(params.BeaconConfig().SecondsPerSlot)) * time.Second).Unix())
 	count, err = f.ReceivedBlocksLastEpoch()
 	require.NoError(t, err)
 	require.Equal(t, uint64(2), count)
 	require.Equal(t, primitives.Slot(65), f.HighestReceivedBlockSlot())
+	require.Equal(t, primitives.Slot(1), f.HighestReceivedBlockDelay())
 
 	// 64 65 66
 	// Received block last epoch is 3

beacon-chain/forkchoice/interfaces.go

@@ -64,6 +64,7 @@ type FastGetter interface {
 	FinalizedPayloadBlockHash() [32]byte
 	HasNode([32]byte) bool
 	HighestReceivedBlockSlot() primitives.Slot
+	HighestReceivedBlockDelay() primitives.Slot
 	IsCanonical(root [32]byte) bool
 	IsOptimistic(root [32]byte) (bool, error)
 	IsViableForCheckpoint(*forkchoicetypes.Checkpoint) (bool, error)

beacon-chain/forkchoice/ro.go

@@ -114,6 +114,13 @@ func (ro *ROForkChoice) HighestReceivedBlockSlot() primitives.Slot {
 	return ro.getter.HighestReceivedBlockSlot()
 }
 
+// HighestReceivedBlockDelay delegates to the underlying forkchoice call, under a lock.
+func (ro *ROForkChoice) HighestReceivedBlockDelay() primitives.Slot {
+	ro.l.RLock()
+	defer ro.l.RUnlock()
+	return ro.getter.HighestReceivedBlockDelay()
+}
+
 // ReceivedBlocksLastEpoch delegates to the underlying forkchoice call, under a lock.
 func (ro *ROForkChoice) ReceivedBlocksLastEpoch() (uint64, error) {
 	ro.l.RLock()

beacon-chain/forkchoice/ro_test.go

@@ -29,6 +29,7 @@ const (
 	unrealizedJustifiedPayloadBlockHashCalled
 	nodeCountCalled
 	highestReceivedBlockSlotCalled
+	highestReceivedBlockDelayCalled
 	receivedBlocksLastEpochCalled
 	weightCalled
 	isOptimisticCalled
@@ -113,6 +114,11 @@ func TestROLocking(t *testing.T) {
 			call: highestReceivedBlockSlotCalled,
 			cb:   func(g FastGetter) { g.HighestReceivedBlockSlot() },
 		},
+		{
+			name: "highestReceivedBlockDelayCalled",
+			call: highestReceivedBlockDelayCalled,
+			cb:   func(g FastGetter) { g.HighestReceivedBlockDelay() },
+		},
 		{
 			name: "receivedBlocksLastEpochCalled",
 			call: receivedBlocksLastEpochCalled,
@@ -245,6 +251,11 @@ func (ro *mockROForkchoice) HighestReceivedBlockSlot() primitives.Slot {
 	return 0
 }
 
+func (ro *mockROForkchoice) HighestReceivedBlockDelay() primitives.Slot {
+	ro.calls = append(ro.calls, highestReceivedBlockDelayCalled)
+	return 0
+}
+
 func (ro *mockROForkchoice) ReceivedBlocksLastEpoch() (uint64, error) {
 	ro.calls = append(ro.calls, receivedBlocksLastEpochCalled)
 	return 0, nil

beacon-chain/gateway/BUILD.bazel

@@ -6,6 +6,7 @@ go_library(
     importpath = "github.com/prysmaticlabs/prysm/v4/beacon-chain/gateway",
     visibility = ["//beacon-chain:__subpackages__"],
     deps = [
+        "//api:go_default_library",
         "//api/gateway:go_default_library",
         "//cmd/beacon-chain/flags:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",

beacon-chain/gateway/helpers.go

@@ -2,6 +2,7 @@ package gateway
 
 import (
 	gwruntime "github.com/grpc-ecosystem/grpc-gateway/v2/runtime"
+	"github.com/prysmaticlabs/prysm/v4/api"
 	"github.com/prysmaticlabs/prysm/v4/api/gateway"
 	"github.com/prysmaticlabs/prysm/v4/cmd/beacon-chain/flags"
 	ethpbalpha "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
@@ -40,7 +41,7 @@ func DefaultConfig(enableDebugRPCEndpoints bool, httpModules string) MuxConfig {
 				},
 			}),
 			gwruntime.WithMarshalerOption(
-				"text/event-stream", &gwruntime.EventSourceJSONPb{},
+				api.EventStreamMediaType, &gwruntime.EventSourceJSONPb{},
 			),
 		)
 		v1AlphaPbHandler = &gateway.PbMux{

beacon-chain/node/BUILD.bazel

@@ -40,6 +40,7 @@ go_library(
         "//beacon-chain/operations/synccommittee:go_default_library",
         "//beacon-chain/operations/voluntaryexits:go_default_library",
         "//beacon-chain/p2p:go_default_library",
+        "//beacon-chain/p2p/peers:go_default_library",
         "//beacon-chain/rpc:go_default_library",
         "//beacon-chain/slasher:go_default_library",
         "//beacon-chain/startup:go_default_library",
@@ -47,6 +48,7 @@ go_library(
         "//beacon-chain/state/stategen:go_default_library",
         "//beacon-chain/sync:go_default_library",
         "//beacon-chain/sync/backfill:go_default_library",
+        "//beacon-chain/sync/backfill/coverage:go_default_library",
         "//beacon-chain/sync/checkpoint:go_default_library",
         "//beacon-chain/sync/genesis:go_default_library",
         "//beacon-chain/sync/initial-sync:go_default_library",

beacon-chain/node/node.go

@@ -42,6 +42,7 @@ import (
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/operations/synccommittee"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/operations/voluntaryexits"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/p2p"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/p2p/peers"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/rpc"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/slasher"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/startup"
@@ -49,6 +50,7 @@ import (
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/state/stategen"
 	regularsync "github.com/prysmaticlabs/prysm/v4/beacon-chain/sync"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/sync/backfill"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/sync/backfill/coverage"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/sync/checkpoint"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/sync/genesis"
 	initialsync "github.com/prysmaticlabs/prysm/v4/beacon-chain/sync/initial-sync"
@@ -113,6 +115,7 @@ type BeaconNode struct {
 	CheckpointInitializer   checkpoint.Initializer
 	forkChoicer             forkchoice.ForkChoicer
 	clockWaiter             startup.ClockWaiter
+	BackfillOpts            []backfill.ServiceOption
 	initialSyncComplete     chan struct{}
 	BlobStorage             *filesystem.BlobStorage
 	blobRetentionEpochs     primitives.Epoch
@@ -215,10 +218,23 @@ func New(cliCtx *cli.Context, cancel context.CancelFunc, opts ...Option) (*Beaco
 		return nil, err
 	}
 
-	bfs := backfill.NewStatus(beacon.db)
-	if err := bfs.Reload(ctx); err != nil {
+	log.Debugln("Registering P2P Service")
+	if err := beacon.registerP2P(cliCtx); err != nil {
+		return nil, err
+	}
+
+	bfs, err := backfill.NewUpdater(ctx, beacon.db)
+	if err != nil {
 		return nil, errors.Wrap(err, "backfill status initialization error")
 	}
+	pa := peers.NewAssigner(beacon.fetchP2P().Peers(), beacon.forkChoicer)
+	bf, err := backfill.NewService(ctx, bfs, beacon.clockWaiter, beacon.fetchP2P(), pa, beacon.BackfillOpts...)
+	if err != nil {
+		return nil, errors.Wrap(err, "error initializing backfill service")
+	}
+	if err := beacon.services.RegisterService(bf); err != nil {
+		return nil, errors.Wrap(err, "error registering backfill service")
+	}
 
 	log.Debugln("Starting State Gen")
 	if err := beacon.startStateGen(ctx, bfs, beacon.forkChoicer); err != nil {
@@ -233,11 +249,6 @@ func New(cliCtx *cli.Context, cancel context.CancelFunc, opts ...Option) (*Beaco
 	beacon.verifyInitWaiter = verification.NewInitializerWaiter(
 		beacon.clockWaiter, forkchoice.NewROForkChoice(beacon.forkChoicer), beacon.stateGen)
 
-	log.Debugln("Registering P2P Service")
-	if err := beacon.registerP2P(cliCtx); err != nil {
-		return nil, err
-	}
-
 	log.Debugln("Registering POW Chain Service")
 	if err := beacon.registerPOWChainService(); err != nil {
 		return nil, err
@@ -534,8 +545,8 @@ func (b *BeaconNode) startSlasherDB(cliCtx *cli.Context) error {
 	return nil
 }
 
-func (b *BeaconNode) startStateGen(ctx context.Context, bfs *backfill.Status, fc forkchoice.ForkChoicer) error {
-	opts := []stategen.Option{stategen.WithBackfillStatus(bfs)}
+func (b *BeaconNode) startStateGen(ctx context.Context, bfs coverage.AvailableBlocker, fc forkchoice.ForkChoicer) error {
+	opts := []stategen.Option{stategen.WithAvailableBlocker(bfs)}
 	sg := stategen.New(b.db, fc, opts...)
 
 	cp, err := b.db.FinalizedCheckpoint(ctx)

beacon-chain/operations/attestations/prepare_forkchoice.go

@@ -42,7 +42,7 @@ func (s *Service) prepareForkChoiceAtts() {
 			switch slotInterval.Interval {
 			case 0:
 				duration := time.Since(t)
-				log.WithField("Duration", duration).Debug("aggregated unaggregated attestations")
+				log.WithField("Duration", duration).Debug("Aggregated unaggregated attestations")
 				batchForkChoiceAttsT1.Observe(float64(duration.Milliseconds()))
 			case 1:
 				batchForkChoiceAttsT2.Observe(float64(time.Since(t).Milliseconds()))

beacon-chain/p2p/message_id.go

@@ -83,7 +83,7 @@ func postAltairMsgID(pmsg *pubsubpb.Message, fEpoch primitives.Epoch) string {
 	decodedData, err := encoder.DecodeSnappy(pmsg.Data, gossipPubSubSize)
 	if err != nil {
 		totalLength, err := math.AddInt(
-			len(params.BeaconConfig().MessageDomainValidSnappy),
+			len(params.BeaconConfig().MessageDomainInvalidSnappy),
 			len(topicLenBytes),
 			topicLen,
 			len(pmsg.Data),

beacon-chain/p2p/peers/BUILD.bazel

@@ -3,6 +3,7 @@ load("@prysm//tools/go:def.bzl", "go_library", "go_test")
 go_library(
     name = "go_default_library",
     srcs = [
+        "assigner.go",
         "log.go",
         "status.go",
     ],
@@ -12,8 +13,10 @@ go_library(
         "//cmd:__subpackages__",
     ],
     deps = [
+        "//beacon-chain/forkchoice/types:go_default_library",
         "//beacon-chain/p2p/peers/peerdata:go_default_library",
         "//beacon-chain/p2p/peers/scorers:go_default_library",
+        "//cmd/beacon-chain/flags:go_default_library",
         "//config/features:go_default_library",
         "//config/params:go_default_library",
         "//consensus-types/primitives:go_default_library",
@@ -28,6 +31,7 @@ go_library(
         "@com_github_libp2p_go_libp2p//core/peer:go_default_library",
         "@com_github_multiformats_go_multiaddr//:go_default_library",
         "@com_github_multiformats_go_multiaddr//net:go_default_library",
+        "@com_github_pkg_errors//:go_default_library",
         "@com_github_prysmaticlabs_go_bitfield//:go_default_library",
         "@com_github_sirupsen_logrus//:go_default_library",
     ],
@@ -36,6 +40,7 @@ go_library(
 go_test(
     name = "go_default_test",
     srcs = [
+        "assigner_test.go",
         "benchmark_test.go",
         "peers_test.go",
         "status_test.go",

beacon-chain/p2p/peers/assigner.go

@@ -0,0 +1,78 @@
+package peers
+
+import (
+	"github.com/libp2p/go-libp2p/core/peer"
+	"github.com/pkg/errors"
+	forkchoicetypes "github.com/prysmaticlabs/prysm/v4/beacon-chain/forkchoice/types"
+	"github.com/prysmaticlabs/prysm/v4/cmd/beacon-chain/flags"
+	"github.com/prysmaticlabs/prysm/v4/config/params"
+	"github.com/sirupsen/logrus"
+)
+
+// FinalizedCheckpointer describes the minimum capability that Assigner needs from forkchoice.
+// That is, the ability to retrieve the latest finalized checkpoint to help with peer evaluation.
+type FinalizedCheckpointer interface {
+	FinalizedCheckpoint() *forkchoicetypes.Checkpoint
+}
+
+// NewAssigner assists in the correct construction of an Assigner by code in other packages,
+// assuring all the important private member fields are given values.
+// The FinalizedCheckpointer is used to retrieve the latest finalized checkpoint each time peers are requested.
+// Peers that report an older finalized checkpoint are filtered out.
+func NewAssigner(s *Status, fc FinalizedCheckpointer) *Assigner {
+	return &Assigner{
+		ps: s,
+		fc: fc,
+	}
+}
+
+// Assigner uses the "BestFinalized" peer scoring method to pick the next-best peer to receive rpc requests.
+type Assigner struct {
+	ps *Status
+	fc FinalizedCheckpointer
+}
+
+// ErrInsufficientSuitable is a sentinel error, signaling that a peer couldn't be assigned because there are currently
+// not enough peers that match our selection criteria to serve rpc requests. It is the responsibility of the caller to
+// look for this error and continue to try calling Assign with appropriate backoff logic.
+var ErrInsufficientSuitable = errors.New("no suitable peers")
+
+func (a *Assigner) freshPeers() ([]peer.ID, error) {
+	required := params.BeaconConfig().MaxPeersToSync
+	if flags.Get().MinimumSyncPeers < required {
+		required = flags.Get().MinimumSyncPeers
+	}
+	_, peers := a.ps.BestFinalized(params.BeaconConfig().MaxPeersToSync, a.fc.FinalizedCheckpoint().Epoch)
+	if len(peers) < required {
+		log.WithFields(logrus.Fields{
+			"suitable": len(peers),
+			"required": required}).Warn("Unable to assign peer while suitable peers < required ")
+		return nil, ErrInsufficientSuitable
+	}
+	return peers, nil
+}
+
+// Assign uses the "BestFinalized" method to select the best peers that agree on a canonical block
+// for the configured finalized epoch. At most `n` peers will be returned. The `busy` param can be used
+// to filter out peers that we know we don't want to connect to, for instance if we are trying to limit
+// the number of outbound requests to each peer from a given component.
+func (a *Assigner) Assign(busy map[peer.ID]bool, n int) ([]peer.ID, error) {
+	best, err := a.freshPeers()
+	if err != nil {
+		return nil, err
+	}
+	return pickBest(busy, n, best), nil
+}
+
+func pickBest(busy map[peer.ID]bool, n int, best []peer.ID) []peer.ID {
+	ps := make([]peer.ID, 0, n)
+	for _, p := range best {
+		if len(ps) == n {
+			return ps
+		}
+		if !busy[p] {
+			ps = append(ps, p)
+		}
+	}
+	return ps
+}

beacon-chain/p2p/peers/assigner_test.go

@@ -0,0 +1,114 @@
+package peers
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/libp2p/go-libp2p/core/peer"
+	"github.com/prysmaticlabs/prysm/v4/testing/require"
+)
+
+func TestPickBest(t *testing.T) {
+	best := testPeerIds(10)
+	cases := []struct {
+		name     string
+		busy     map[peer.ID]bool
+		n        int
+		best     []peer.ID
+		expected []peer.ID
+	}{
+		{
+			name: "",
+			n:    0,
+		},
+		{
+			name:     "none busy",
+			n:        1,
+			expected: best[0:1],
+		},
+		{
+			name:     "all busy except last",
+			n:        1,
+			busy:     testBusyMap(best[0 : len(best)-1]),
+			expected: best[len(best)-1:],
+		},
+		{
+			name:     "all busy except i=5",
+			n:        1,
+			busy:     testBusyMap(append(append([]peer.ID{}, best[0:5]...), best[6:]...)),
+			expected: []peer.ID{best[5]},
+		},
+		{
+			name: "all busy - 0 results",
+			n:    1,
+			busy: testBusyMap(best),
+		},
+		{
+			name:     "first half busy",
+			n:        5,
+			busy:     testBusyMap(best[0:5]),
+			expected: best[5:],
+		},
+		{
+			name:     "back half busy",
+			n:        5,
+			busy:     testBusyMap(best[5:]),
+			expected: best[0:5],
+		},
+		{
+			name:     "pick all ",
+			n:        10,
+			expected: best,
+		},
+		{
+			name: "none available",
+			n:    10,
+			best: []peer.ID{},
+		},
+		{
+			name:     "not enough",
+			n:        10,
+			best:     best[0:1],
+			expected: best[0:1],
+		},
+		{
+			name:     "not enough, some busy",
+			n:        10,
+			best:     best[0:6],
+			busy:     testBusyMap(best[0:5]),
+			expected: best[5:6],
+		},
+	}
+	for _, c := range cases {
+		name := fmt.Sprintf("n=%d", c.n)
+		if c.name != "" {
+			name += " " + c.name
+		}
+		t.Run(name, func(t *testing.T) {
+			if c.best == nil {
+				c.best = best
+			}
+			pb := pickBest(c.busy, c.n, c.best)
+			require.Equal(t, len(c.expected), len(pb))
+			for i := range c.expected {
+				require.Equal(t, c.expected[i], pb[i])
+			}
+		})
+	}
+}
+
+func testBusyMap(b []peer.ID) map[peer.ID]bool {
+	m := make(map[peer.ID]bool)
+	for i := range b {
+		m[b[i]] = true
+	}
+	return m
+}
+
+func testPeerIds(n int) []peer.ID {
+	pids := make([]peer.ID, n)
+	for i := range pids {
+		pids[i] = peer.ID(fmt.Sprintf("%d", i))
+	}
+	return pids
+}

beacon-chain/rpc/core/BUILD.bazel

@@ -38,6 +38,7 @@ go_library(
         "//time/slots:go_default_library",
         "@com_github_pkg_errors//:go_default_library",
         "@com_github_sirupsen_logrus//:go_default_library",
+        "@io_opencensus_go//trace:go_default_library",
         "@org_golang_google_grpc//codes:go_default_library",
         "@org_golang_x_sync//errgroup:go_default_library",
     ],

beacon-chain/rpc/core/service.go

@@ -11,14 +11,15 @@ import (
 )
 
 type Service struct {
-	HeadFetcher        blockchain.HeadFetcher
-	FinalizedFetcher   blockchain.FinalizationFetcher
-	GenesisTimeFetcher blockchain.TimeFetcher
-	SyncChecker        sync.Checker
-	Broadcaster        p2p.Broadcaster
-	SyncCommitteePool  synccommittee.Pool
-	OperationNotifier  opfeed.Notifier
-	AttestationCache   *cache.AttestationCache
-	StateGen           stategen.StateManager
-	P2P                p2p.Broadcaster
+	HeadFetcher           blockchain.HeadFetcher
+	FinalizedFetcher      blockchain.FinalizationFetcher
+	GenesisTimeFetcher    blockchain.TimeFetcher
+	SyncChecker           sync.Checker
+	Broadcaster           p2p.Broadcaster
+	SyncCommitteePool     synccommittee.Pool
+	OperationNotifier     opfeed.Notifier
+	AttestationCache      *cache.AttestationCache
+	StateGen              stategen.StateManager
+	P2P                   p2p.Broadcaster
+	OptimisticModeFetcher blockchain.OptimisticModeFetcher
 }

beacon-chain/rpc/core/validator.go

@@ -29,9 +29,12 @@ import (
 	prysmTime "github.com/prysmaticlabs/prysm/v4/time"
 	"github.com/prysmaticlabs/prysm/v4/time/slots"
 	"github.com/sirupsen/logrus"
+	"go.opencensus.io/trace"
 	"golang.org/x/sync/errgroup"
 )
 
+var errOptimisticMode = errors.New("the node is currently optimistic and cannot serve validators")
+
 // AggregateBroadcastFailedError represents an error scenario where
 // broadcasting an aggregate selection proof failed.
 type AggregateBroadcastFailedError struct {
@@ -56,6 +59,9 @@ func (s *Service) ComputeValidatorPerformance(
 	ctx context.Context,
 	req *ethpb.ValidatorPerformanceRequest,
 ) (*ethpb.ValidatorPerformanceResponse, *RpcError) {
+	ctx, span := trace.StartSpan(ctx, "coreService.ComputeValidatorPerformance")
+	defer span.End()
+
 	if s.SyncChecker.Syncing() {
 		return nil, &RpcError{Reason: Unavailable, Err: errors.New("Syncing to latest head, not ready to respond")}
 	}
@@ -211,6 +217,9 @@ func (s *Service) SubmitSignedContributionAndProof(
 	ctx context.Context,
 	req *ethpb.SignedContributionAndProof,
 ) *RpcError {
+	ctx, span := trace.StartSpan(ctx, "coreService.SubmitSignedContributionAndProof")
+	defer span.End()
+
 	errs, ctx := errgroup.WithContext(ctx)
 
 	// Broadcasting and saving contribution into the pool in parallel. As one fail should not affect another.
@@ -243,6 +252,9 @@ func (s *Service) SubmitSignedAggregateSelectionProof(
 	ctx context.Context,
 	req *ethpb.SignedAggregateSubmitRequest,
 ) *RpcError {
+	ctx, span := trace.StartSpan(ctx, "coreService.SubmitSignedAggregateSelectionProof")
+	defer span.End()
+
 	if req.SignedAggregateAndProof == nil || req.SignedAggregateAndProof.Message == nil ||
 		req.SignedAggregateAndProof.Message.Aggregate == nil || req.SignedAggregateAndProof.Message.Aggregate.Data == nil {
 		return &RpcError{Err: errors.New("signed aggregate request can't be nil"), Reason: BadRequest}
@@ -315,6 +327,9 @@ func (s *Service) AggregatedSigAndAggregationBits(
 func (s *Service) GetAttestationData(
 	ctx context.Context, req *ethpb.AttestationDataRequest,
 ) (*ethpb.AttestationData, *RpcError) {
+	ctx, span := trace.StartSpan(ctx, "coreService.GetAttestationData")
+	defer span.End()
+
 	if req.Slot != s.GenesisTimeFetcher.CurrentSlot() {
 		return nil, &RpcError{Reason: BadRequest, Err: errors.Errorf("invalid request: slot %d is not the current slot %d", req.Slot, s.GenesisTimeFetcher.CurrentSlot())}
 	}
@@ -368,6 +383,14 @@ func (s *Service) GetAttestationData(
 			},
 		}, nil
 	}
+	// cache miss, we need to check for optimistic status before proceeding
+	optimistic, err := s.OptimisticModeFetcher.IsOptimistic(ctx)
+	if err != nil {
+		return nil, &RpcError{Reason: Internal, Err: err}
+	}
+	if optimistic {
+		return nil, &RpcError{Reason: Unavailable, Err: errOptimisticMode}
+	}
 
 	headRoot, err := s.HeadFetcher.HeadRoot(ctx)
 	if err != nil {
@@ -412,6 +435,9 @@ func (s *Service) GetAttestationData(
 // SubmitSyncMessage submits the sync committee message to the network.
 // It also saves the sync committee message into the pending pool for block inclusion.
 func (s *Service) SubmitSyncMessage(ctx context.Context, msg *ethpb.SyncCommitteeMessage) *RpcError {
+	ctx, span := trace.StartSpan(ctx, "coreService.SubmitSyncMessage")
+	defer span.End()
+
 	errs, ctx := errgroup.WithContext(ctx)
 
 	headSyncCommitteeIndices, err := s.HeadFetcher.HeadSyncCommitteeIndices(ctx, msg.ValidatorIndex, msg.Slot)

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

@@ -62,7 +62,7 @@ func (s *Server) GetBlock(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	if httputil.SszRequested(r) {
+	if httputil.RespondWithSsz(r) {
 		s.getBlockSSZ(ctx, w, blk)
 	} else {
 		s.getBlock(ctx, w, blk)
@@ -105,7 +105,7 @@ func (s *Server) GetBlockV2(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	if httputil.SszRequested(r) {
+	if httputil.RespondWithSsz(r) {
 		s.getBlockSSZV2(ctx, w, blk)
 	} else {
 		s.getBlockV2(ctx, w, blk)
@@ -205,7 +205,7 @@ func (s *Server) GetBlindedBlock(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	if httputil.SszRequested(r) {
+	if httputil.RespondWithSsz(r) {
 		s.getBlindedBlockSSZ(ctx, w, blk)
 	} else {
 		s.getBlindedBlock(ctx, w, blk)
@@ -953,8 +953,7 @@ func (s *Server) PublishBlindedBlock(w http.ResponseWriter, r *http.Request) {
 	if shared.IsSyncing(r.Context(), w, s.SyncChecker, s.HeadFetcher, s.TimeFetcher, s.OptimisticModeFetcher) {
 		return
 	}
-	isSSZ := httputil.SszRequested(r)
-	if isSSZ {
+	if httputil.IsRequestSsz(r) {
 		s.publishBlindedBlockSSZ(ctx, w, r, false)
 	} else {
 		s.publishBlindedBlock(ctx, w, r, false)
@@ -978,8 +977,7 @@ func (s *Server) PublishBlindedBlockV2(w http.ResponseWriter, r *http.Request) {
 	if shared.IsSyncing(r.Context(), w, s.SyncChecker, s.HeadFetcher, s.TimeFetcher, s.OptimisticModeFetcher) {
 		return
 	}
-	isSSZ := httputil.SszRequested(r)
-	if isSSZ {
+	if httputil.IsRequestSsz(r) {
 		s.publishBlindedBlockSSZ(ctx, w, r, true)
 	} else {
 		s.publishBlindedBlock(ctx, w, r, true)
@@ -1250,8 +1248,7 @@ func (s *Server) PublishBlock(w http.ResponseWriter, r *http.Request) {
 	if shared.IsSyncing(r.Context(), w, s.SyncChecker, s.HeadFetcher, s.TimeFetcher, s.OptimisticModeFetcher) {
 		return
 	}
-	isSSZ := httputil.SszRequested(r)
-	if isSSZ {
+	if httputil.IsRequestSsz(r) {
 		s.publishBlockSSZ(ctx, w, r, false)
 	} else {
 		s.publishBlock(ctx, w, r, false)
@@ -1273,8 +1270,7 @@ func (s *Server) PublishBlockV2(w http.ResponseWriter, r *http.Request) {
 	if shared.IsSyncing(r.Context(), w, s.SyncChecker, s.HeadFetcher, s.TimeFetcher, s.OptimisticModeFetcher) {
 		return
 	}
-	isSSZ := httputil.SszRequested(r)
-	if isSSZ {
+	if httputil.IsRequestSsz(r) {
 		s.publishBlockSSZ(ctx, w, r, true)
 	} else {
 		s.publishBlock(ctx, w, r, true)

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

@@ -1169,7 +1169,7 @@ func TestPublishBlockSSZ(t *testing.T) {
 		ssz, err := genericBlock.GetPhase0().MarshalSSZ()
 		require.NoError(t, err)
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader(ssz))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		request.Header.Set(api.VersionHeader, version.String(version.Phase0))
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
@@ -1199,7 +1199,7 @@ func TestPublishBlockSSZ(t *testing.T) {
 		ssz, err := genericBlock.GetAltair().MarshalSSZ()
 		require.NoError(t, err)
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader(ssz))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		request.Header.Set(api.VersionHeader, version.String(version.Altair))
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
@@ -1224,7 +1224,7 @@ func TestPublishBlockSSZ(t *testing.T) {
 		ssz, err := genericBlock.GetBellatrix().MarshalSSZ()
 		require.NoError(t, err)
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader(ssz))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		request.Header.Set(api.VersionHeader, version.String(version.Bellatrix))
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
@@ -1250,7 +1250,7 @@ func TestPublishBlockSSZ(t *testing.T) {
 		ssz, err := genericBlock.GetCapella().MarshalSSZ()
 		require.NoError(t, err)
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader(ssz))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		request.Header.Set(api.VersionHeader, version.String(version.Capella))
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
@@ -1276,7 +1276,7 @@ func TestPublishBlockSSZ(t *testing.T) {
 		ssz, err := genericBlock.GetDeneb().MarshalSSZ()
 		require.NoError(t, err)
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader(ssz))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		request.Header.Set(api.VersionHeader, version.String(version.Deneb))
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
@@ -1296,7 +1296,7 @@ func TestPublishBlockSSZ(t *testing.T) {
 		ssz, err := genericBlock.GetBlindedBellatrix().MarshalSSZ()
 		require.NoError(t, err)
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader(ssz))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		request.Header.Set(api.VersionHeader, version.String(version.Bellatrix))
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
@@ -1317,7 +1317,7 @@ func TestPublishBlockSSZ(t *testing.T) {
 		ssz, err := genericBlock.GetBellatrix().MarshalSSZ()
 		require.NoError(t, err)
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader(ssz))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		request.Header.Set(api.VersionHeader, version.String(version.Capella))
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
@@ -1335,7 +1335,7 @@ func TestPublishBlockSSZ(t *testing.T) {
 		}
 
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader([]byte("foo")))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
 		server.PublishBlock(writer, request)
@@ -1531,7 +1531,7 @@ func TestPublishBlindedBlockSSZ(t *testing.T) {
 		ssz, err := genericBlock.GetPhase0().MarshalSSZ()
 		require.NoError(t, err)
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader(ssz))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		request.Header.Set(api.VersionHeader, version.String(version.Phase0))
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
@@ -1561,7 +1561,7 @@ func TestPublishBlindedBlockSSZ(t *testing.T) {
 		ssz, err := genericBlock.GetAltair().MarshalSSZ()
 		require.NoError(t, err)
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader(ssz))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		request.Header.Set(api.VersionHeader, version.String(version.Altair))
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
@@ -1587,7 +1587,7 @@ func TestPublishBlindedBlockSSZ(t *testing.T) {
 		ssz, err := genericBlock.GetBlindedBellatrix().MarshalSSZ()
 		require.NoError(t, err)
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader(ssz))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		request.Header.Set(api.VersionHeader, version.String(version.Bellatrix))
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
@@ -1613,7 +1613,7 @@ func TestPublishBlindedBlockSSZ(t *testing.T) {
 		ssz, err := genericBlock.GetBlindedCapella().MarshalSSZ()
 		require.NoError(t, err)
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader(ssz))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		request.Header.Set(api.VersionHeader, version.String(version.Capella))
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
@@ -1639,7 +1639,7 @@ func TestPublishBlindedBlockSSZ(t *testing.T) {
 		ssz, err := genericBlock.GetBlindedDeneb().MarshalSSZ()
 		require.NoError(t, err)
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader(ssz))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		request.Header.Set(api.VersionHeader, version.String(version.Deneb))
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
@@ -1672,7 +1672,7 @@ func TestPublishBlindedBlockSSZ(t *testing.T) {
 		ssz, err := genericBlock.GetBlindedBellatrix().MarshalSSZ()
 		require.NoError(t, err)
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader(ssz))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		request.Header.Set(api.VersionHeader, version.String(version.Capella))
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
@@ -1690,7 +1690,7 @@ func TestPublishBlindedBlockSSZ(t *testing.T) {
 		}
 
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader([]byte("foo")))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
 		server.PublishBlindedBlock(writer, request)
@@ -1899,7 +1899,7 @@ func TestPublishBlockV2SSZ(t *testing.T) {
 		ssz, err := genericBlock.GetPhase0().MarshalSSZ()
 		require.NoError(t, err)
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader(ssz))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		request.Header.Set(api.VersionHeader, version.String(version.Phase0))
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
@@ -1929,7 +1929,7 @@ func TestPublishBlockV2SSZ(t *testing.T) {
 		ssz, err := genericBlock.GetAltair().MarshalSSZ()
 		require.NoError(t, err)
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader(ssz))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		request.Header.Set(api.VersionHeader, version.String(version.Altair))
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
@@ -1954,7 +1954,7 @@ func TestPublishBlockV2SSZ(t *testing.T) {
 		ssz, err := genericBlock.GetBellatrix().MarshalSSZ()
 		require.NoError(t, err)
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader(ssz))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		request.Header.Set(api.VersionHeader, version.String(version.Bellatrix))
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
@@ -1980,7 +1980,7 @@ func TestPublishBlockV2SSZ(t *testing.T) {
 		ssz, err := genericBlock.GetCapella().MarshalSSZ()
 		require.NoError(t, err)
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader(ssz))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		request.Header.Set(api.VersionHeader, version.String(version.Capella))
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
@@ -2006,7 +2006,7 @@ func TestPublishBlockV2SSZ(t *testing.T) {
 		ssz, err := genericBlock.GetDeneb().MarshalSSZ()
 		require.NoError(t, err)
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader(ssz))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		request.Header.Set(api.VersionHeader, version.String(version.Deneb))
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
@@ -2026,7 +2026,7 @@ func TestPublishBlockV2SSZ(t *testing.T) {
 		ssz, err := genericBlock.GetBlindedBellatrix().MarshalSSZ()
 		require.NoError(t, err)
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader(ssz))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		request.Header.Set(api.VersionHeader, version.String(version.Bellatrix))
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
@@ -2047,7 +2047,7 @@ func TestPublishBlockV2SSZ(t *testing.T) {
 		ssz, err := genericBlock.GetBellatrix().MarshalSSZ()
 		require.NoError(t, err)
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader(ssz))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		request.Header.Set(api.VersionHeader, version.String(version.Capella))
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
@@ -2061,7 +2061,7 @@ func TestPublishBlockV2SSZ(t *testing.T) {
 		}
 
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader([]byte(rpctesting.CapellaBlock)))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
 		server.PublishBlockV2(writer, request)
@@ -2078,7 +2078,7 @@ func TestPublishBlockV2SSZ(t *testing.T) {
 		}
 
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader([]byte("foo")))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
 		server.PublishBlockV2(writer, request)
@@ -2286,7 +2286,7 @@ func TestPublishBlindedBlockV2SSZ(t *testing.T) {
 		ssz, err := genericBlock.GetPhase0().MarshalSSZ()
 		require.NoError(t, err)
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader(ssz))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		request.Header.Set(api.VersionHeader, version.String(version.Phase0))
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
@@ -2316,7 +2316,7 @@ func TestPublishBlindedBlockV2SSZ(t *testing.T) {
 		ssz, err := genericBlock.GetAltair().MarshalSSZ()
 		require.NoError(t, err)
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader(ssz))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		request.Header.Set(api.VersionHeader, version.String(version.Altair))
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
@@ -2342,7 +2342,7 @@ func TestPublishBlindedBlockV2SSZ(t *testing.T) {
 		ssz, err := genericBlock.GetBlindedBellatrix().MarshalSSZ()
 		require.NoError(t, err)
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader(ssz))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		request.Header.Set(api.VersionHeader, version.String(version.Bellatrix))
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
@@ -2368,7 +2368,7 @@ func TestPublishBlindedBlockV2SSZ(t *testing.T) {
 		ssz, err := genericBlock.GetBlindedCapella().MarshalSSZ()
 		require.NoError(t, err)
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader(ssz))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		request.Header.Set(api.VersionHeader, version.String(version.Capella))
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
@@ -2394,7 +2394,7 @@ func TestPublishBlindedBlockV2SSZ(t *testing.T) {
 		ssz, err := genericBlock.GetBlindedDeneb().MarshalSSZ()
 		require.NoError(t, err)
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader(ssz))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		request.Header.Set(api.VersionHeader, version.String(version.Deneb))
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
@@ -2427,7 +2427,7 @@ func TestPublishBlindedBlockV2SSZ(t *testing.T) {
 		ssz, err := genericBlock.GetBlindedBellatrix().MarshalSSZ()
 		require.NoError(t, err)
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader(ssz))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		request.Header.Set(api.VersionHeader, version.String(version.Capella))
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
@@ -2441,7 +2441,7 @@ func TestPublishBlindedBlockV2SSZ(t *testing.T) {
 		}
 
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader([]byte(rpctesting.BlindedCapellaBlock)))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
 		server.PublishBlockV2(writer, request)
@@ -2458,7 +2458,7 @@ func TestPublishBlindedBlockV2SSZ(t *testing.T) {
 		}
 
 		request := httptest.NewRequest(http.MethodPost, "http://foo.example", bytes.NewReader([]byte("foo")))
-		request.Header.Set("Accept", api.OctetStreamMediaType)
+		request.Header.Set("Content-Type", api.OctetStreamMediaType)
 		writer := httptest.NewRecorder()
 		writer.Body = &bytes.Buffer{}
 		server.PublishBlindedBlockV2(writer, request)

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

@@ -46,8 +46,7 @@ func (s *Server) Blobs(w http.ResponseWriter, r *http.Request) {
 	for i := range verifiedBlobs {
 		sidecars = append(sidecars, verifiedBlobs[i].BlobSidecar)
 	}
-	ssz := httputil.SszRequested(r)
-	if ssz {
+	if httputil.RespondWithSsz(r) {
 		sidecarResp := &eth.BlobSidecars{
 			Sidecars: sidecars,
 		}

beacon-chain/rpc/eth/blob/structs.go

@@ -12,5 +12,5 @@ type Sidecar struct {
 	SignedBeaconBlockHeader  *shared.SignedBeaconBlockHeader `json:"signed_block_header"`
 	KzgCommitment            string                          `json:"kzg_commitment"`
 	KzgProof                 string                          `json:"kzg_proof"`
-	CommitmentInclusionProof []string                        `json:"commitment_inclusion_proof"`
+	CommitmentInclusionProof []string                        `json:"kzg_commitment_inclusion_proof"`
 }

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

@@ -54,7 +54,7 @@ func (s *Server) GetBeaconStateV2(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	if httputil.SszRequested(r) {
+	if httputil.RespondWithSsz(r) {
 		s.getBeaconStateSSZV2(ctx, w, []byte(stateId))
 	} else {
 		s.getBeaconStateV2(ctx, w, []byte(stateId))

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

@@ -471,7 +471,7 @@ func TestGetForkChoice(t *testing.T) {
 	require.NoError(t, store.UpdateFinalizedCheckpoint(fc))
 	s := &Server{ForkchoiceFetcher: &blockchainmock.ChainService{ForkChoiceStore: store}}
 
-	request := httptest.NewRequest(http.MethodGet, "http://example.com/eth/v2/debug/fork_choice", nil)
+	request := httptest.NewRequest(http.MethodGet, "http://example.com/eth/v1/debug/fork_choice", nil)
 	writer := httptest.NewRecorder()
 	writer.Body = &bytes.Buffer{}
 

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

@@ -8,8 +8,9 @@ go_library(
         "structs.go",
     ],
     importpath = "github.com/prysmaticlabs/prysm/v4/beacon-chain/rpc/eth/events",
-    visibility = ["//beacon-chain:__subpackages__"],
+    visibility = ["//visibility:public"],
     deps = [
+        "//api:go_default_library",
         "//beacon-chain/blockchain:go_default_library",
         "//beacon-chain/core/feed:go_default_library",
         "//beacon-chain/core/feed/operation:go_default_library",
@@ -18,8 +19,10 @@ go_library(
         "//beacon-chain/core/time:go_default_library",
         "//beacon-chain/core/transition:go_default_library",
         "//beacon-chain/rpc/eth/shared:go_default_library",
+        "//config/params:go_default_library",
         "//network/httputil:go_default_library",
         "//proto/eth/v1:go_default_library",
+        "//proto/eth/v2:go_default_library",
         "//runtime/version:go_default_library",
         "//time/slots:go_default_library",
         "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",

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

@@ -5,8 +5,10 @@ import (
 	"encoding/json"
 	"fmt"
 	"net/http"
+	time2 "time"
 
 	"github.com/ethereum/go-ethereum/common/hexutil"
+	"github.com/prysmaticlabs/prysm/v4/api"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/blockchain"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/core/feed"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/core/feed/operation"
@@ -15,8 +17,10 @@ import (
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/core/time"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/core/transition"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/rpc/eth/shared"
+	"github.com/prysmaticlabs/prysm/v4/config/params"
 	"github.com/prysmaticlabs/prysm/v4/network/httputil"
 	ethpb "github.com/prysmaticlabs/prysm/v4/proto/eth/v1"
+	ethpbv2 "github.com/prysmaticlabs/prysm/v4/proto/eth/v2"
 	"github.com/prysmaticlabs/prysm/v4/runtime/version"
 	"github.com/prysmaticlabs/prysm/v4/time/slots"
 	log "github.com/sirupsen/logrus"
@@ -48,6 +52,10 @@ const (
 	ProposerSlashingTopic = "proposer_slashing"
 	// AttesterSlashingTopic represents a new attester slashing event topic
 	AttesterSlashingTopic = "attester_slashing"
+	// LightClientFinalityUpdateTopic represents a new light client finality update event topic.
+	LightClientFinalityUpdateTopic = "light_client_finality_update"
+	// LightClientOptimisticUpdateTopic represents a new light client optimistic update event topic.
+	LightClientOptimisticUpdateTopic = "light_client_optimistic_update"
 )
 
 const topicDataMismatch = "Event data type %T does not correspond to event topic %s"
@@ -55,18 +63,20 @@ const topicDataMismatch = "Event data type %T does not correspond to event topic
 const chanBuffer = 1000
 
 var casesHandled = map[string]bool{
-	HeadTopic:                      true,
-	BlockTopic:                     true,
-	AttestationTopic:               true,
-	VoluntaryExitTopic:             true,
-	FinalizedCheckpointTopic:       true,
-	ChainReorgTopic:                true,
-	SyncCommitteeContributionTopic: true,
-	BLSToExecutionChangeTopic:      true,
-	PayloadAttributesTopic:         true,
-	BlobSidecarTopic:               true,
-	ProposerSlashingTopic:          true,
-	AttesterSlashingTopic:          true,
+	HeadTopic:                        true,
+	BlockTopic:                       true,
+	AttestationTopic:                 true,
+	VoluntaryExitTopic:               true,
+	FinalizedCheckpointTopic:         true,
+	ChainReorgTopic:                  true,
+	SyncCommitteeContributionTopic:   true,
+	BLSToExecutionChangeTopic:        true,
+	PayloadAttributesTopic:           true,
+	BlobSidecarTopic:                 true,
+	ProposerSlashingTopic:            true,
+	AttesterSlashingTopic:            true,
+	LightClientFinalityUpdateTopic:   true,
+	LightClientOptimisticUpdateTopic: true,
 }
 
 // StreamEvents provides an endpoint to subscribe to the beacon node Server-Sent-Events stream.
@@ -106,16 +116,24 @@ func (s *Server) StreamEvents(w http.ResponseWriter, r *http.Request) {
 	defer stateSub.Unsubscribe()
 
 	// Set up SSE response headers
-	w.Header().Set("Content-Type", "text/event-stream")
-	w.Header().Set("Connection", "keep-alive")
+	w.Header().Set("Content-Type", api.EventStreamMediaType)
+	w.Header().Set("Connection", api.KeepAlive)
 
 	// Handle each event received and context cancellation.
+	// We send a keepalive dummy message immediately to prevent clients
+	// stalling while waiting for the first response chunk.
+	// After that we send a keepalive dummy message every SECONDS_PER_SLOT
+	// to prevent anyone (e.g. proxy servers) from closing connections.
+	sendKeepalive(w, flusher)
+	keepaliveTicker := time2.NewTicker(time2.Duration(params.BeaconConfig().SecondsPerSlot) * time2.Second)
 	for {
 		select {
 		case event := <-opsChan:
 			handleBlockOperationEvents(w, flusher, topicsMap, event)
 		case event := <-stateChan:
 			s.handleStateEvents(ctx, w, flusher, topicsMap, event)
+		case <-keepaliveTicker.C:
+			sendKeepalive(w, flusher)
 		case <-ctx.Done():
 			return
 		}
@@ -262,6 +280,72 @@ func (s *Server) handleStateEvents(ctx context.Context, w http.ResponseWriter, f
 			ExecutionOptimistic: checkpointData.ExecutionOptimistic,
 		}
 		send(w, flusher, FinalizedCheckpointTopic, checkpoint)
+	case statefeed.LightClientFinalityUpdate:
+		if _, ok := requestedTopics[LightClientFinalityUpdateTopic]; !ok {
+			return
+		}
+		updateData, ok := event.Data.(*ethpbv2.LightClientFinalityUpdateWithVersion)
+		if !ok {
+			write(w, flusher, topicDataMismatch, event.Data, LightClientFinalityUpdateTopic)
+			return
+		}
+
+		var finalityBranch []string
+		for _, b := range updateData.Data.FinalityBranch {
+			finalityBranch = append(finalityBranch, hexutil.Encode(b))
+		}
+		update := &LightClientFinalityUpdateEvent{
+			Version: version.String(int(updateData.Version)),
+			Data: &LightClientFinalityUpdate{
+				AttestedHeader: &shared.BeaconBlockHeader{
+					Slot:          fmt.Sprintf("%d", updateData.Data.AttestedHeader.Slot),
+					ProposerIndex: fmt.Sprintf("%d", updateData.Data.AttestedHeader.ProposerIndex),
+					ParentRoot:    hexutil.Encode(updateData.Data.AttestedHeader.ParentRoot),
+					StateRoot:     hexutil.Encode(updateData.Data.AttestedHeader.StateRoot),
+					BodyRoot:      hexutil.Encode(updateData.Data.AttestedHeader.BodyRoot),
+				},
+				FinalizedHeader: &shared.BeaconBlockHeader{
+					Slot:          fmt.Sprintf("%d", updateData.Data.FinalizedHeader.Slot),
+					ProposerIndex: fmt.Sprintf("%d", updateData.Data.FinalizedHeader.ProposerIndex),
+					ParentRoot:    hexutil.Encode(updateData.Data.FinalizedHeader.ParentRoot),
+					StateRoot:     hexutil.Encode(updateData.Data.FinalizedHeader.StateRoot),
+				},
+				FinalityBranch: finalityBranch,
+				SyncAggregate: &shared.SyncAggregate{
+					SyncCommitteeBits:      hexutil.Encode(updateData.Data.SyncAggregate.SyncCommitteeBits),
+					SyncCommitteeSignature: hexutil.Encode(updateData.Data.SyncAggregate.SyncCommitteeSignature),
+				},
+				SignatureSlot: fmt.Sprintf("%d", updateData.Data.SignatureSlot),
+			},
+		}
+		send(w, flusher, LightClientFinalityUpdateTopic, update)
+	case statefeed.LightClientOptimisticUpdate:
+		if _, ok := requestedTopics[LightClientOptimisticUpdateTopic]; !ok {
+			return
+		}
+		updateData, ok := event.Data.(*ethpbv2.LightClientOptimisticUpdateWithVersion)
+		if !ok {
+			write(w, flusher, topicDataMismatch, event.Data, LightClientOptimisticUpdateTopic)
+			return
+		}
+		update := &LightClientOptimisticUpdateEvent{
+			Version: version.String(int(updateData.Version)),
+			Data: &LightClientOptimisticUpdate{
+				AttestedHeader: &shared.BeaconBlockHeader{
+					Slot:          fmt.Sprintf("%d", updateData.Data.AttestedHeader.Slot),
+					ProposerIndex: fmt.Sprintf("%d", updateData.Data.AttestedHeader.ProposerIndex),
+					ParentRoot:    hexutil.Encode(updateData.Data.AttestedHeader.ParentRoot),
+					StateRoot:     hexutil.Encode(updateData.Data.AttestedHeader.StateRoot),
+					BodyRoot:      hexutil.Encode(updateData.Data.AttestedHeader.BodyRoot),
+				},
+				SyncAggregate: &shared.SyncAggregate{
+					SyncCommitteeBits:      hexutil.Encode(updateData.Data.SyncAggregate.SyncCommitteeBits),
+					SyncCommitteeSignature: hexutil.Encode(updateData.Data.SyncAggregate.SyncCommitteeSignature),
+				},
+				SignatureSlot: fmt.Sprintf("%d", updateData.Data.SignatureSlot),
+			},
+		}
+		send(w, flusher, LightClientOptimisticUpdateTopic, update)
 	case statefeed.Reorg:
 		if _, ok := requestedTopics[ChainReorgTopic]; !ok {
 			return
@@ -431,6 +515,10 @@ func send(w http.ResponseWriter, flusher http.Flusher, name string, data interfa
 	write(w, flusher, "event: %s\ndata: %s\n\n", name, string(j))
 }
 
+func sendKeepalive(w http.ResponseWriter, flusher http.Flusher) {
+	write(w, flusher, ":\n\n")
+}
+
 func write(w http.ResponseWriter, flusher http.Flusher, format string, a ...any) {
 	_, err := fmt.Fprintf(w, format, a...)
 	if err != nil {

beacon-chain/rpc/eth/events/events_test.go

@@ -375,7 +375,9 @@ func TestStreamEvents_OperationsEvents(t *testing.T) {
 	})
 }
 
-const operationsResult = `event: attestation
+const operationsResult = `:
+
+event: attestation
 data: {"aggregation_bits":"0x00","data":{"slot":"0","index":"0","beacon_block_root":"0x0000000000000000000000000000000000000000000000000000000000000000","source":{"epoch":"0","root":"0x0000000000000000000000000000000000000000000000000000000000000000"},"target":{"epoch":"0","root":"0x0000000000000000000000000000000000000000000000000000000000000000"}},"signature":"0x000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"}
 
 event: attestation
@@ -401,7 +403,9 @@ data: {"signed_header_1":{"message":{"slot":"0","proposer_index":"0","parent_roo
 
 `
 
-const stateResult = `event: head
+const stateResult = `:
+
+event: head
 data: {"slot":"0","block":"0x0000000000000000000000000000000000000000000000000000000000000000","state":"0x0000000000000000000000000000000000000000000000000000000000000000","epoch_transition":true,"execution_optimistic":false,"previous_duty_dependent_root":"0x0000000000000000000000000000000000000000000000000000000000000000","current_duty_dependent_root":"0x0000000000000000000000000000000000000000000000000000000000000000"}
 
 event: finalized_checkpoint
@@ -415,17 +419,23 @@ data: {"slot":"0","block":"0xeade62f0457b2fdf48e7d3fc4b60736688286be7c7a3ac4c9a1
 
 `
 
-const payloadAttributesBellatrixResult = `event: payload_attributes
+const payloadAttributesBellatrixResult = `:
+
+event: payload_attributes
 data: {"version":"bellatrix","data":{"proposer_index":"0","proposal_slot":"1","parent_block_number":"0","parent_block_root":"0x0000000000000000000000000000000000000000000000000000000000000000","parent_block_hash":"0x0000000000000000000000000000000000000000000000000000000000000000","payload_attributes":{"timestamp":"12","prev_randao":"0x0000000000000000000000000000000000000000000000000000000000000000","suggested_fee_recipient":"0x0000000000000000000000000000000000000000"}}}
 
 `
 
-const payloadAttributesCapellaResult = `event: payload_attributes
+const payloadAttributesCapellaResult = `:
+
+event: payload_attributes
 data: {"version":"capella","data":{"proposer_index":"0","proposal_slot":"1","parent_block_number":"0","parent_block_root":"0x0000000000000000000000000000000000000000000000000000000000000000","parent_block_hash":"0x0000000000000000000000000000000000000000000000000000000000000000","payload_attributes":{"timestamp":"12","prev_randao":"0x0000000000000000000000000000000000000000000000000000000000000000","suggested_fee_recipient":"0x0000000000000000000000000000000000000000","withdrawals":[]}}}
 
 `
 
-const payloadAttributesDenebResult = `event: payload_attributes
+const payloadAttributesDenebResult = `:
+
+event: payload_attributes
 data: {"version":"deneb","data":{"proposer_index":"0","proposal_slot":"1","parent_block_number":"0","parent_block_root":"0x0000000000000000000000000000000000000000000000000000000000000000","parent_block_hash":"0x0000000000000000000000000000000000000000000000000000000000000000","payload_attributes":{"timestamp":"12","prev_randao":"0x0000000000000000000000000000000000000000000000000000000000000000","suggested_fee_recipient":"0x0000000000000000000000000000000000000000","withdrawals":[],"parent_beacon_block_root":"0xbef96cb938fd48b2403d3e662664325abb0102ed12737cbb80d717520e50cf4a"}}}
 
 `

beacon-chain/rpc/eth/events/structs.go

@@ -92,3 +92,27 @@ type BlobSidecarEvent struct {
 	KzgCommitment string `json:"kzg_commitment"`
 	VersionedHash string `json:"versioned_hash"`
 }
+
+type LightClientFinalityUpdateEvent struct {
+	Version string                     `json:"version"`
+	Data    *LightClientFinalityUpdate `json:"data"`
+}
+
+type LightClientFinalityUpdate struct {
+	AttestedHeader  *shared.BeaconBlockHeader `json:"attested_header"`
+	FinalizedHeader *shared.BeaconBlockHeader `json:"finalized_header"`
+	FinalityBranch  []string                  `json:"finality_branch"`
+	SyncAggregate   *shared.SyncAggregate     `json:"sync_aggregate"`
+	SignatureSlot   string                    `json:"signature_slot"`
+}
+
+type LightClientOptimisticUpdateEvent struct {
+	Version string                       `json:"version"`
+	Data    *LightClientOptimisticUpdate `json:"data"`
+}
+
+type LightClientOptimisticUpdate struct {
+	AttestedHeader *shared.BeaconBlockHeader `json:"attested_header"`
+	SyncAggregate  *shared.SyncAggregate     `json:"sync_aggregate"`
+	SignatureSlot  string                    `json:"signature_slot"`
+}

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

@@ -8,9 +8,10 @@ import (
 
 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/gorilla/mux"
-	"github.com/wealdtech/go-bytesutil"
 	"go.opencensus.io/trace"
 
+	"github.com/wealdtech/go-bytesutil"
+
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/rpc/eth/shared"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/state"
 	"github.com/prysmaticlabs/prysm/v4/config/params"
@@ -219,11 +220,7 @@ func (s *Server) GetLightClientUpdatesByRange(w http.ResponseWriter, req *http.R
 		return
 	}
 
-	response := &LightClientUpdatesByRangeResponse{
-		Updates: updates,
-	}
-
-	httputil.WriteJson(w, response)
+	httputil.WriteJson(w, updates)
 }
 
 // GetLightClientFinalityUpdate - implements https://github.com/ethereum/beacon-APIs/blob/263f4ed6c263c967f13279c7a9f5629b51c5fc55/apis/beacon/light_client/finality_update.yaml

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

@@ -171,12 +171,12 @@ func TestLightClientHandler_GetLightClientUpdatesByRange(t *testing.T) {
 	s.GetLightClientUpdatesByRange(writer, request)
 
 	require.Equal(t, http.StatusOK, writer.Code)
-	resp := &LightClientUpdatesByRangeResponse{}
-	require.NoError(t, json.Unmarshal(writer.Body.Bytes(), resp))
-	require.Equal(t, 1, len(resp.Updates))
-	require.Equal(t, "capella", resp.Updates[0].Version)
-	require.Equal(t, hexutil.Encode(attestedHeader.BodyRoot), resp.Updates[0].Data.AttestedHeader.BodyRoot)
-	require.NotNil(t, resp.Updates)
+	var resp []LightClientUpdateWithVersion
+	require.NoError(t, json.Unmarshal(writer.Body.Bytes(), &resp))
+	require.Equal(t, 1, len(resp))
+	require.Equal(t, "capella", resp[0].Version)
+	require.Equal(t, hexutil.Encode(attestedHeader.BodyRoot), resp[0].Data.AttestedHeader.BodyRoot)
+	require.NotNil(t, resp)
 }
 
 func TestLightClientHandler_GetLightClientUpdatesByRange_TooBigInputCount(t *testing.T) {
@@ -274,12 +274,12 @@ func TestLightClientHandler_GetLightClientUpdatesByRange_TooBigInputCount(t *tes
 	s.GetLightClientUpdatesByRange(writer, request)
 
 	require.Equal(t, http.StatusOK, writer.Code)
-	resp := &LightClientUpdatesByRangeResponse{}
-	require.NoError(t, json.Unmarshal(writer.Body.Bytes(), resp))
-	require.Equal(t, 1, len(resp.Updates)) // Even with big count input, the response is still the max available period, which is 1 in test case.
-	require.Equal(t, "capella", resp.Updates[0].Version)
-	require.Equal(t, hexutil.Encode(attestedHeader.BodyRoot), resp.Updates[0].Data.AttestedHeader.BodyRoot)
-	require.NotNil(t, resp.Updates)
+	var resp []LightClientUpdateWithVersion
+	require.NoError(t, json.Unmarshal(writer.Body.Bytes(), &resp))
+	require.Equal(t, 1, len(resp)) // Even with big count input, the response is still the max available period, which is 1 in test case.
+	require.Equal(t, "capella", resp[0].Version)
+	require.Equal(t, hexutil.Encode(attestedHeader.BodyRoot), resp[0].Data.AttestedHeader.BodyRoot)
+	require.NotNil(t, resp)
 }
 
 func TestLightClientHandler_GetLightClientUpdatesByRange_TooEarlyPeriod(t *testing.T) {
@@ -377,12 +377,12 @@ func TestLightClientHandler_GetLightClientUpdatesByRange_TooEarlyPeriod(t *testi
 	s.GetLightClientUpdatesByRange(writer, request)
 
 	require.Equal(t, http.StatusOK, writer.Code)
-	resp := &LightClientUpdatesByRangeResponse{}
-	require.NoError(t, json.Unmarshal(writer.Body.Bytes(), resp))
-	require.Equal(t, 1, len(resp.Updates))
-	require.Equal(t, "capella", resp.Updates[0].Version)
-	require.Equal(t, hexutil.Encode(attestedHeader.BodyRoot), resp.Updates[0].Data.AttestedHeader.BodyRoot)
-	require.NotNil(t, resp.Updates)
+	var resp []LightClientUpdateWithVersion
+	require.NoError(t, json.Unmarshal(writer.Body.Bytes(), &resp))
+	require.Equal(t, 1, len(resp))
+	require.Equal(t, "capella", resp[0].Version)
+	require.Equal(t, hexutil.Encode(attestedHeader.BodyRoot), resp[0].Data.AttestedHeader.BodyRoot)
+	require.NotNil(t, resp)
 }
 
 func TestLightClientHandler_GetLightClientUpdatesByRange_TooBigCount(t *testing.T) {
@@ -480,12 +480,12 @@ func TestLightClientHandler_GetLightClientUpdatesByRange_TooBigCount(t *testing.
 	s.GetLightClientUpdatesByRange(writer, request)
 
 	require.Equal(t, http.StatusOK, writer.Code)
-	resp := &LightClientUpdatesByRangeResponse{}
-	require.NoError(t, json.Unmarshal(writer.Body.Bytes(), resp))
-	require.Equal(t, 1, len(resp.Updates))
-	require.Equal(t, "capella", resp.Updates[0].Version)
-	require.Equal(t, hexutil.Encode(attestedHeader.BodyRoot), resp.Updates[0].Data.AttestedHeader.BodyRoot)
-	require.NotNil(t, resp.Updates)
+	var resp []LightClientUpdateWithVersion
+	require.NoError(t, json.Unmarshal(writer.Body.Bytes(), &resp))
+	require.Equal(t, 1, len(resp))
+	require.Equal(t, "capella", resp[0].Version)
+	require.Equal(t, hexutil.Encode(attestedHeader.BodyRoot), resp[0].Data.AttestedHeader.BodyRoot)
+	require.NotNil(t, resp)
 }
 
 func TestLightClientHandler_GetLightClientUpdatesByRange_BeforeAltair(t *testing.T) {
@@ -583,9 +583,6 @@ func TestLightClientHandler_GetLightClientUpdatesByRange_BeforeAltair(t *testing
 	s.GetLightClientUpdatesByRange(writer, request)
 
 	require.Equal(t, http.StatusNotFound, writer.Code)
-	resp := &LightClientUpdatesByRangeResponse{}
-	require.NoError(t, json.Unmarshal(writer.Body.Bytes(), resp))
-	require.Equal(t, 0, len(resp.Updates))
 }
 
 func TestLightClientHandler_GetLightClientFinalityUpdate(t *testing.T) {

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

@@ -296,11 +296,16 @@ func newLightClientUpdateToJSON(input *v2.LightClientUpdate) *LightClientUpdate
 		nextSyncCommittee = shared.SyncCommitteeFromConsensus(migration.V2SyncCommitteeToV1Alpha1(input.NextSyncCommittee))
 	}
 
+	var finalizedHeader *shared.BeaconBlockHeader
+	if input.FinalizedHeader != nil {
+		finalizedHeader = shared.BeaconBlockHeaderFromConsensus(migration.V1HeaderToV1Alpha1(input.FinalizedHeader))
+	}
+
 	return &LightClientUpdate{
 		AttestedHeader:          shared.BeaconBlockHeaderFromConsensus(migration.V1HeaderToV1Alpha1(input.AttestedHeader)),
 		NextSyncCommittee:       nextSyncCommittee,
 		NextSyncCommitteeBranch: branchToJSON(input.NextSyncCommitteeBranch),
-		FinalizedHeader:         shared.BeaconBlockHeaderFromConsensus(migration.V1HeaderToV1Alpha1(input.FinalizedHeader)),
+		FinalizedHeader:         finalizedHeader,
 		FinalityBranch:          branchToJSON(input.FinalityBranch),
 		SyncAggregate:           syncAggregateToJSON(input.SyncAggregate),
 		SignatureSlot:           strconv.FormatUint(uint64(input.SignatureSlot), 10),

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

@@ -17,11 +17,11 @@ type LightClientBootstrap struct {
 
 type LightClientUpdate struct {
 	AttestedHeader          *shared.BeaconBlockHeader `json:"attested_header"`
-	NextSyncCommittee       *shared.SyncCommittee     `json:"next_sync_committee"`
-	FinalizedHeader         *shared.BeaconBlockHeader `json:"finalized_header"`
+	NextSyncCommittee       *shared.SyncCommittee     `json:"next_sync_committee,omitempty"`
+	FinalizedHeader         *shared.BeaconBlockHeader `json:"finalized_header,omitempty"`
 	SyncAggregate           *shared.SyncAggregate     `json:"sync_aggregate"`
-	NextSyncCommitteeBranch []string                  `json:"next_sync_committee_branch"`
-	FinalityBranch          []string                  `json:"finality_branch"`
+	NextSyncCommitteeBranch []string                  `json:"next_sync_committee_branch,omitempty"`
+	FinalityBranch          []string                  `json:"finality_branch,omitempty"`
 	SignatureSlot           string                    `json:"signature_slot"`
 }
 

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

@@ -62,7 +62,6 @@ func (s *Server) BlockRewards(w http.ResponseWriter, r *http.Request) {
 
 // AttestationRewards retrieves attestation reward info for validators specified by array of public keys or validator index.
 // If no array is provided, return reward info for every validator.
-// TODO: Inclusion delay
 func (s *Server) AttestationRewards(w http.ResponseWriter, r *http.Request) {
 	st, ok := s.attRewardsState(w, r)
 	if !ok {
@@ -277,7 +276,10 @@ func idealAttRewards(
 					IsPrevEpochTargetAttester:    true,
 					IsPrevEpochHeadAttester:      true,
 				})
-				idealRewards = append(idealRewards, IdealAttestationReward{EffectiveBalance: strconv.FormatUint(effectiveBalance, 10)})
+				idealRewards = append(idealRewards, IdealAttestationReward{
+					EffectiveBalance: strconv.FormatUint(effectiveBalance, 10),
+					Inactivity:       strconv.FormatUint(0, 10),
+				})
 				break
 			}
 		}
@@ -299,6 +301,11 @@ func idealAttRewards(
 		} else {
 			idealRewards[i].Target = strconv.FormatUint(d.TargetReward, 10)
 		}
+		if d.InactivityPenalty > 0 {
+			idealRewards[i].Inactivity = fmt.Sprintf("-%s", strconv.FormatUint(d.InactivityPenalty, 10))
+		} else {
+			idealRewards[i].Inactivity = strconv.FormatUint(d.InactivityPenalty, 10)
+		}
 	}
 	return idealRewards, true
 }
@@ -331,6 +338,11 @@ func totalAttRewards(
 		} else {
 			totalRewards[i].Target = strconv.FormatUint(d.TargetReward, 10)
 		}
+		if d.InactivityPenalty > 0 {
+			totalRewards[i].Inactivity = fmt.Sprintf("-%s", strconv.FormatUint(d.InactivityPenalty, 10))
+		} else {
+			totalRewards[i].Inactivity = strconv.FormatUint(d.InactivityPenalty, 10)
+		}
 	}
 	return totalRewards, true
 }

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

@@ -396,7 +396,7 @@ func TestAttestationRewards(t *testing.T) {
 		FinalizationFetcher:   mockChainService,
 	}
 
-	t.Run("ok - ideal rewards", func(t *testing.T) {
+	t.Run("ideal rewards", func(t *testing.T) {
 		url := "http://only.the.epoch.number.at.the.end.is.important/1"
 		request := httptest.NewRequest("POST", url, nil)
 		writer := httptest.NewRecorder()
@@ -419,7 +419,7 @@ func TestAttestationRewards(t *testing.T) {
 		}
 		assert.Equal(t, uint64(20756849), sum)
 	})
-	t.Run("ok - filtered vals", func(t *testing.T) {
+	t.Run("filtered vals", func(t *testing.T) {
 		url := "http://only.the.epoch.number.at.the.end.is.important/1"
 		var body bytes.Buffer
 		pubkey := fmt.Sprintf("%#x", secretKeys[10].PublicKey().Marshal())
@@ -448,7 +448,7 @@ func TestAttestationRewards(t *testing.T) {
 		}
 		assert.Equal(t, uint64(794265), sum)
 	})
-	t.Run("ok - all vals", func(t *testing.T) {
+	t.Run("all vals", func(t *testing.T) {
 		url := "http://only.the.epoch.number.at.the.end.is.important/1"
 		request := httptest.NewRequest("POST", url, nil)
 		writer := httptest.NewRecorder()
@@ -471,36 +471,12 @@ func TestAttestationRewards(t *testing.T) {
 		}
 		assert.Equal(t, uint64(54221955), sum)
 	})
-	t.Run("ok - penalty", func(t *testing.T) {
-		st, err := util.NewBeaconStateCapella()
-		require.NoError(t, err)
-		require.NoError(t, st.SetSlot(params.BeaconConfig().SlotsPerEpoch*3-1))
-		validators := make([]*eth.Validator, 0, valCount)
-		balances := make([]uint64, 0, valCount)
-		for i := 0; i < valCount; i++ {
-			blsKey, err := bls.RandKey()
-			require.NoError(t, err)
-			validators = append(validators, &eth.Validator{
-				PublicKey:         blsKey.PublicKey().Marshal(),
-				ExitEpoch:         params.BeaconConfig().FarFutureEpoch,
-				WithdrawableEpoch: params.BeaconConfig().FarFutureEpoch,
-				EffectiveBalance:  params.BeaconConfig().MaxEffectiveBalance / 64 * uint64(i),
-			})
-			balances = append(balances, params.BeaconConfig().MaxEffectiveBalance/64*uint64(i))
-		}
+	t.Run("penalty", func(t *testing.T) {
+		st := st.Copy()
+		validators := st.Validators()
 		validators[63].Slashed = true
 		require.NoError(t, st.SetValidators(validators))
-		require.NoError(t, st.SetBalances(balances))
-		require.NoError(t, st.SetInactivityScores(make([]uint64, len(validators))))
-		participation := make([]byte, len(validators))
-		for i := range participation {
-			participation[i] = 0b111
-		}
-		require.NoError(t, st.SetCurrentParticipationBits(participation))
-		require.NoError(t, st.SetPreviousParticipationBits(participation))
 
-		currentSlot := params.BeaconConfig().SlotsPerEpoch * 3
-		mockChainService := &mock.ChainService{Optimistic: true, Slot: &currentSlot}
 		s := &Server{
 			Stater: &testutil.MockStater{StatesBySlot: map[primitives.Slot]state.BeaconState{
 				params.BeaconConfig().SlotsPerEpoch*3 - 1: st,
@@ -525,8 +501,44 @@ func TestAttestationRewards(t *testing.T) {
 		resp := &AttestationRewardsResponse{}
 		require.NoError(t, json.Unmarshal(writer.Body.Bytes(), resp))
 		assert.Equal(t, "0", resp.Data.TotalRewards[0].Head)
-		assert.Equal(t, "-432270", resp.Data.TotalRewards[0].Source)
-		assert.Equal(t, "-802788", resp.Data.TotalRewards[0].Target)
+		assert.Equal(t, "-439299", resp.Data.TotalRewards[0].Source)
+		assert.Equal(t, "-815841", resp.Data.TotalRewards[0].Target)
+		assert.Equal(t, "0", resp.Data.TotalRewards[0].Inactivity)
+	})
+	t.Run("inactivity", func(t *testing.T) {
+		st := st.Copy()
+		validators := st.Validators()
+		validators[63].Slashed = true
+		require.NoError(t, st.SetValidators(validators))
+		inactivityScores, err := st.InactivityScores()
+		require.NoError(t, err)
+		inactivityScores[63] = 10
+		require.NoError(t, st.SetInactivityScores(inactivityScores))
+
+		s := &Server{
+			Stater: &testutil.MockStater{StatesBySlot: map[primitives.Slot]state.BeaconState{
+				params.BeaconConfig().SlotsPerEpoch*3 - 1: st,
+			}},
+			TimeFetcher:           mockChainService,
+			OptimisticModeFetcher: mockChainService,
+			FinalizationFetcher:   mockChainService,
+		}
+
+		url := "http://only.the.epoch.number.at.the.end.is.important/1"
+		var body bytes.Buffer
+		valIds, err := json.Marshal([]string{"63"})
+		require.NoError(t, err)
+		_, err = body.Write(valIds)
+		require.NoError(t, err)
+		request := httptest.NewRequest("POST", url, &body)
+		writer := httptest.NewRecorder()
+		writer.Body = &bytes.Buffer{}
+
+		s.AttestationRewards(writer, request)
+		assert.Equal(t, http.StatusOK, writer.Code)
+		resp := &AttestationRewardsResponse{}
+		require.NoError(t, json.Unmarshal(writer.Body.Bytes(), resp))
+		assert.Equal(t, "-4768", resp.Data.TotalRewards[0].Inactivity)
 	})
 	t.Run("invalid validator index/pubkey", func(t *testing.T) {
 		url := "http://only.the.epoch.number.at.the.end.is.important/1"

beacon-chain/rpc/eth/rewards/structs.go

@@ -31,6 +31,7 @@ type IdealAttestationReward struct {
 	Head             string `json:"head"`
 	Target           string `json:"target"`
 	Source           string `json:"source"`
+	Inactivity       string `json:"inactivity"`
 }
 
 type TotalAttestationReward struct {
@@ -38,7 +39,7 @@ type TotalAttestationReward struct {
 	Head           string `json:"head"`
 	Target         string `json:"target"`
 	Source         string `json:"source"`
-	InclusionDelay string `json:"inclusion_delay"`
+	Inactivity     string `json:"inactivity"`
 }
 
 type SyncCommitteeRewardsResponse struct {

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

@@ -388,10 +388,6 @@ func (s *Server) GetAttestationData(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	if isOptimistic, err := shared.IsOptimistic(ctx, w, s.OptimisticModeFetcher); isOptimistic || err != nil {
-		return
-	}
-
 	_, slot, ok := shared.UintFromQuery(w, r, "slot", true)
 	if !ok {
 		return

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

@@ -201,7 +201,7 @@ func (s *Server) ProduceBlockV3(w http.ResponseWriter, r *http.Request) {
 }
 
 func (s *Server) produceBlockV3(ctx context.Context, w http.ResponseWriter, r *http.Request, v1alpha1req *eth.BlockRequest, requiredType blockType) {
-	isSSZ := httputil.SszRequested(r)
+	isSSZ := httputil.RespondWithSsz(r)
 	v1alpha1resp, err := s.V1Alpha1Server.GetBeaconBlock(ctx, v1alpha1req)
 	if err != nil {
 		httputil.HandleError(w, err.Error(), http.StatusInternalServerError)

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

@@ -831,10 +831,11 @@ func TestGetAttestationData(t *testing.T) {
 			TimeFetcher:           chain,
 			OptimisticModeFetcher: chain,
 			CoreService: &core.Service{
-				HeadFetcher:        chain,
-				GenesisTimeFetcher: chain,
-				FinalizedFetcher:   chain,
-				AttestationCache:   cache.NewAttestationCache(),
+				HeadFetcher:           chain,
+				GenesisTimeFetcher:    chain,
+				FinalizedFetcher:      chain,
+				AttestationCache:      cache.NewAttestationCache(),
+				OptimisticModeFetcher: chain,
 			},
 		}
 
@@ -914,10 +915,11 @@ func TestGetAttestationData(t *testing.T) {
 			TimeFetcher:           chain,
 			OptimisticModeFetcher: chain,
 			CoreService: &core.Service{
-				AttestationCache:   cache.NewAttestationCache(),
-				GenesisTimeFetcher: chain,
-				HeadFetcher:        chain,
-				FinalizedFetcher:   chain,
+				AttestationCache:      cache.NewAttestationCache(),
+				GenesisTimeFetcher:    chain,
+				HeadFetcher:           chain,
+				FinalizedFetcher:      chain,
+				OptimisticModeFetcher: chain,
 			},
 		}
 
@@ -959,8 +961,9 @@ func TestGetAttestationData(t *testing.T) {
 			TimeFetcher:           chain,
 			OptimisticModeFetcher: chain,
 			CoreService: &core.Service{
-				GenesisTimeFetcher: chain,
-				FinalizedFetcher:   chain,
+				GenesisTimeFetcher:    chain,
+				OptimisticModeFetcher: chain,
+				FinalizedFetcher:      chain,
 			},
 		}
 
@@ -1017,10 +1020,11 @@ func TestGetAttestationData(t *testing.T) {
 			TimeFetcher:           chain,
 			OptimisticModeFetcher: chain,
 			CoreService: &core.Service{
-				HeadFetcher:        chain,
-				GenesisTimeFetcher: chain,
-				StateGen:           stategen.New(db, doublylinkedtree.New()),
-				FinalizedFetcher:   chain,
+				HeadFetcher:           chain,
+				GenesisTimeFetcher:    chain,
+				OptimisticModeFetcher: chain,
+				StateGen:              stategen.New(db, doublylinkedtree.New()),
+				FinalizedFetcher:      chain,
 			},
 		}
 
@@ -1065,10 +1069,11 @@ func TestGetAttestationData(t *testing.T) {
 			TimeFetcher:           chain,
 			OptimisticModeFetcher: chain,
 			CoreService: &core.Service{
-				AttestationCache:   cache.NewAttestationCache(),
-				HeadFetcher:        chain,
-				GenesisTimeFetcher: chain,
-				FinalizedFetcher:   chain,
+				AttestationCache:      cache.NewAttestationCache(),
+				OptimisticModeFetcher: chain,
+				HeadFetcher:           chain,
+				GenesisTimeFetcher:    chain,
+				FinalizedFetcher:      chain,
 			},
 		}
 
@@ -1151,10 +1156,11 @@ func TestGetAttestationData(t *testing.T) {
 			TimeFetcher:           chain,
 			OptimisticModeFetcher: chain,
 			CoreService: &core.Service{
-				AttestationCache:   cache.NewAttestationCache(),
-				HeadFetcher:        chain,
-				GenesisTimeFetcher: chain,
-				FinalizedFetcher:   chain,
+				AttestationCache:      cache.NewAttestationCache(),
+				OptimisticModeFetcher: chain,
+				HeadFetcher:           chain,
+				GenesisTimeFetcher:    chain,
+				FinalizedFetcher:      chain,
 			},
 		}
 
@@ -1192,14 +1198,14 @@ func TestGetAttestationData(t *testing.T) {
 func TestProduceSyncCommitteeContribution(t *testing.T) {
 	root := bytesutil.PadTo([]byte("0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2"), 32)
 	sig := bls.NewAggregateSignature().Marshal()
-	messsage := &ethpbalpha.SyncCommitteeMessage{
+	message := &ethpbalpha.SyncCommitteeMessage{
 		Slot:           1,
 		BlockRoot:      root,
 		ValidatorIndex: 0,
 		Signature:      sig,
 	}
 	syncCommitteePool := synccommittee.NewStore()
-	require.NoError(t, syncCommitteePool.SaveSyncCommitteeMessage(messsage))
+	require.NoError(t, syncCommitteePool.SaveSyncCommitteeMessage(message))
 	server := Server{
 		CoreService: &core.Service{
 			HeadFetcher: &mockChain.ChainService{

beacon-chain/rpc/lookup/BUILD.bazel

@@ -24,6 +24,7 @@ go_library(
         "//time/slots:go_default_library",
         "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
         "@com_github_pkg_errors//:go_default_library",
+        "@com_github_sirupsen_logrus//:go_default_library",
         "@io_opencensus_go//trace:go_default_library",
     ],
 )

beacon-chain/rpc/lookup/blocker.go

@@ -19,6 +19,7 @@ import (
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v4/encoding/bytesutil"
 	"github.com/prysmaticlabs/prysm/v4/time/slots"
+	log "github.com/sirupsen/logrus"
 )
 
 // BlockIdParseError represents an error scenario where a block ID could not be parsed.
@@ -210,7 +211,10 @@ func (p *BeaconDbBlocker) Blobs(ctx context.Context, id string, indices []uint64
 	if len(indices) == 0 {
 		m, err := p.BlobStorage.Indices(bytesutil.ToBytes32(root))
 		if err != nil {
-			return nil, &core.RpcError{Err: errors.Wrapf(err, "could not retrieve blob indices for root %#x", root), Reason: core.Internal}
+			log.WithFields(log.Fields{
+				"block root": hexutil.Encode(root),
+			}).Error(errors.Wrapf(err, "could not retrieve blob indices for root %#x", root))
+			return nil, &core.RpcError{Err: fmt.Errorf("could not retrieve blob indices for root %#x", root), Reason: core.Internal}
 		}
 		for k, v := range m {
 			if v {
@@ -223,7 +227,11 @@ func (p *BeaconDbBlocker) Blobs(ctx context.Context, id string, indices []uint64
 	for i, index := range indices {
 		vblob, err := p.BlobStorage.Get(bytesutil.ToBytes32(root), index)
 		if err != nil {
-			return nil, &core.RpcError{Err: errors.Wrapf(err, "could not retrieve blob for block root %#x at index %d", root, index), Reason: core.Internal}
+			log.WithFields(log.Fields{
+				"block root": hexutil.Encode(root),
+				"blob index": index,
+			}).Error(errors.Wrapf(err, "could not retrieve blob for block root %#x at index %d", root, index))
+			return nil, &core.RpcError{Err: fmt.Errorf("could not retrieve blob for block root %#x at index %d", root, index), Reason: core.Internal}
 		}
 		blobs[i] = &vblob
 	}

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

@@ -4,7 +4,7 @@ go_library(
     name = "go_default_library",
     srcs = [
         "aggregator.go",
-        "assignments.go",
+        "duties.go",
         "attester.go",
         "blocks.go",
         "construct_generic_block.go",
@@ -38,7 +38,6 @@ go_library(
         "//beacon-chain/builder:go_default_library",
         "//beacon-chain/cache:go_default_library",
         "//beacon-chain/cache/depositcache:go_default_library",
-        "//beacon-chain/core/altair:go_default_library",
         "//beacon-chain/core/blocks:go_default_library",
         "//beacon-chain/core/feed:go_default_library",
         "//beacon-chain/core/feed/block:go_default_library",
@@ -66,7 +65,6 @@ go_library(
         "//config/features:go_default_library",
         "//config/fieldparams:go_default_library",
         "//config/params:go_default_library",
-        "//consensus-types:go_default_library",
         "//consensus-types/blocks:go_default_library",
         "//consensus-types/interfaces:go_default_library",
         "//consensus-types/payload-attribute:go_default_library",
@@ -91,13 +89,13 @@ go_library(
         "//time/slots:go_default_library",
         "@com_github_ethereum_go_ethereum//common:go_default_library",
         "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
+        "@com_github_golang_protobuf//ptypes/empty",
         "@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_prysmaticlabs_go_bitfield//:go_default_library",
         "@com_github_sirupsen_logrus//:go_default_library",
-        "@io_bazel_rules_go//proto/wkt:empty_go_proto",
         "@io_opencensus_go//trace:go_default_library",
         "@org_golang_google_grpc//codes:go_default_library",
         "@org_golang_google_grpc//status:go_default_library",
@@ -141,6 +139,7 @@ common_deps = [
     "//beacon-chain/sync/initial-sync/testing:go_default_library",
     "//config/fieldparams:go_default_library",
     "//config/params:go_default_library",
+    "//consensus-types:go_default_library",
     "//consensus-types/blocks:go_default_library",
     "//consensus-types/interfaces:go_default_library",
     "//consensus-types/primitives:go_default_library",
@@ -179,7 +178,7 @@ go_test(
     timeout = "moderate",
     srcs = [
         "aggregator_test.go",
-        "assignments_test.go",
+        "duties_test.go",
         "attester_test.go",
         "blocks_test.go",
         "construct_generic_block_test.go",

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

@@ -31,12 +31,6 @@ func (vs *Server) GetAttestationData(ctx context.Context, req *ethpb.Attestation
 	if vs.SyncChecker.Syncing() {
 		return nil, status.Errorf(codes.Unavailable, "Syncing to latest head, not ready to respond")
 	}
-
-	// An optimistic validator MUST NOT participate in attestation. (i.e., sign across the DOMAIN_BEACON_ATTESTER, DOMAIN_SELECTION_PROOF or DOMAIN_AGGREGATE_AND_PROOF domains).
-	if err := vs.optimisticStatus(ctx); err != nil {
-		return nil, err
-	}
-
 	res, err := vs.CoreService.GetAttestationData(ctx, req)
 	if err != nil {
 		return nil, status.Errorf(core.ErrorReasonToGRPC(err.Reason), "Could not get attestation data: %v", err.Err)

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

@@ -61,10 +61,11 @@ func TestAttestationDataAtSlot_HandlesFarAwayJustifiedEpoch(t *testing.T) {
 		OptimisticModeFetcher: &mock.ChainService{Optimistic: false},
 		TimeFetcher:           &mock.ChainService{Genesis: time.Now().Add(time.Duration(-1*offset) * time.Second)},
 		CoreService: &core.Service{
-			AttestationCache:   cache.NewAttestationCache(),
-			HeadFetcher:        &mock.ChainService{TargetRoot: blockRoot, Root: blockRoot[:]},
-			GenesisTimeFetcher: &mock.ChainService{Genesis: time.Now().Add(time.Duration(-1*offset) * time.Second)},
-			FinalizedFetcher:   &mock.ChainService{CurrentJustifiedCheckPoint: justifiedCheckpoint},
+			AttestationCache:      cache.NewAttestationCache(),
+			HeadFetcher:           &mock.ChainService{TargetRoot: blockRoot, Root: blockRoot[:]},
+			GenesisTimeFetcher:    &mock.ChainService{Genesis: time.Now().Add(time.Duration(-1*offset) * time.Second)},
+			FinalizedFetcher:      &mock.ChainService{CurrentJustifiedCheckPoint: justifiedCheckpoint},
+			OptimisticModeFetcher: &mock.ChainService{Optimistic: false},
 		},
 	}
 

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

@@ -116,8 +116,9 @@ func TestGetAttestationData_OK(t *testing.T) {
 			GenesisTimeFetcher: &mock.ChainService{
 				Genesis: time.Now().Add(time.Duration(-1*offset) * time.Second),
 			},
-			FinalizedFetcher: &mock.ChainService{CurrentJustifiedCheckPoint: justifiedCheckpoint},
-			AttestationCache: cache.NewAttestationCache(),
+			FinalizedFetcher:      &mock.ChainService{CurrentJustifiedCheckPoint: justifiedCheckpoint},
+			AttestationCache:      cache.NewAttestationCache(),
+			OptimisticModeFetcher: &mock.ChainService{Optimistic: false},
 		},
 	}
 
@@ -176,7 +177,8 @@ func BenchmarkGetAttestationDataConcurrent(b *testing.B) {
 			GenesisTimeFetcher: &mock.ChainService{
 				Genesis: time.Now().Add(time.Duration(-1*offset) * time.Second),
 			},
-			FinalizedFetcher: &mock.ChainService{CurrentJustifiedCheckPoint: justifiedCheckpoint},
+			OptimisticModeFetcher: &mock.ChainService{Optimistic: false},
+			FinalizedFetcher:      &mock.ChainService{CurrentJustifiedCheckPoint: justifiedCheckpoint},
 		},
 	}
 
@@ -222,9 +224,10 @@ func TestGetAttestationData_Optimistic(t *testing.T) {
 		OptimisticModeFetcher: &mock.ChainService{Optimistic: true},
 		TimeFetcher:           &mock.ChainService{Genesis: time.Now()},
 		CoreService: &core.Service{
-			GenesisTimeFetcher: &mock.ChainService{Genesis: time.Now()},
-			HeadFetcher:        &mock.ChainService{},
-			AttestationCache:   cache.NewAttestationCache(),
+			GenesisTimeFetcher:    &mock.ChainService{Genesis: time.Now()},
+			HeadFetcher:           &mock.ChainService{},
+			AttestationCache:      cache.NewAttestationCache(),
+			OptimisticModeFetcher: &mock.ChainService{Optimistic: true},
 		},
 	}
 	_, err := as.GetAttestationData(context.Background(), &ethpb.AttestationDataRequest{})
@@ -240,10 +243,11 @@ func TestGetAttestationData_Optimistic(t *testing.T) {
 		OptimisticModeFetcher: &mock.ChainService{Optimistic: false},
 		TimeFetcher:           &mock.ChainService{Genesis: time.Now()},
 		CoreService: &core.Service{
-			AttestationCache:   cache.NewAttestationCache(),
-			GenesisTimeFetcher: &mock.ChainService{Genesis: time.Now()},
-			HeadFetcher:        &mock.ChainService{Optimistic: false, State: beaconState},
-			FinalizedFetcher:   &mock.ChainService{CurrentJustifiedCheckPoint: &ethpb.Checkpoint{}},
+			AttestationCache:      cache.NewAttestationCache(),
+			GenesisTimeFetcher:    &mock.ChainService{Genesis: time.Now()},
+			HeadFetcher:           &mock.ChainService{Optimistic: false, State: beaconState},
+			FinalizedFetcher:      &mock.ChainService{CurrentJustifiedCheckPoint: &ethpb.Checkpoint{}},
+			OptimisticModeFetcher: &mock.ChainService{Optimistic: false},
 		},
 	}
 	_, err = as.GetAttestationData(context.Background(), &ethpb.AttestationDataRequest{})
@@ -260,7 +264,8 @@ func TestServer_GetAttestationData_InvalidRequestSlot(t *testing.T) {
 		OptimisticModeFetcher: &mock.ChainService{Optimistic: false},
 		TimeFetcher:           &mock.ChainService{Genesis: time.Now().Add(time.Duration(-1*offset) * time.Second)},
 		CoreService: &core.Service{
-			GenesisTimeFetcher: &mock.ChainService{Genesis: time.Now().Add(time.Duration(-1*offset) * time.Second)},
+			GenesisTimeFetcher:    &mock.ChainService{Genesis: time.Now().Add(time.Duration(-1*offset) * time.Second)},
+			OptimisticModeFetcher: &mock.ChainService{Optimistic: false},
 		},
 	}
 
@@ -301,10 +306,11 @@ func TestServer_GetAttestationData_RequestSlotIsDifferentThanCurrentSlot(t *test
 		OptimisticModeFetcher: &mock.ChainService{Optimistic: false},
 		TimeFetcher:           &mock.ChainService{Genesis: time.Now().Add(time.Duration(-1*offset) * time.Second)},
 		CoreService: &core.Service{
-			HeadFetcher:        &mock.ChainService{TargetRoot: blockRoot2, Root: blockRoot[:]},
-			GenesisTimeFetcher: &mock.ChainService{Genesis: time.Now().Add(time.Duration(-1*offset) * time.Second)},
-			StateGen:           stategen.New(db, doublylinkedtree.New()),
-			FinalizedFetcher:   &mock.ChainService{CurrentJustifiedCheckPoint: justifiedCheckpoint},
+			HeadFetcher:           &mock.ChainService{TargetRoot: blockRoot2, Root: blockRoot[:]},
+			GenesisTimeFetcher:    &mock.ChainService{Genesis: time.Now().Add(time.Duration(-1*offset) * time.Second)},
+			StateGen:              stategen.New(db, doublylinkedtree.New()),
+			FinalizedFetcher:      &mock.ChainService{CurrentJustifiedCheckPoint: justifiedCheckpoint},
+			OptimisticModeFetcher: &mock.ChainService{Optimistic: false},
 		},
 	}
 	util.SaveBlock(t, ctx, db, block)
@@ -346,8 +352,9 @@ func TestGetAttestationData_SucceedsInFirstEpoch(t *testing.T) {
 			HeadFetcher: &mock.ChainService{
 				TargetRoot: targetRoot, Root: blockRoot[:],
 			},
-			GenesisTimeFetcher: &mock.ChainService{Genesis: prysmTime.Now().Add(time.Duration(-1*offset) * time.Second)},
-			FinalizedFetcher:   &mock.ChainService{CurrentJustifiedCheckPoint: justifiedCheckpoint},
+			GenesisTimeFetcher:    &mock.ChainService{Genesis: prysmTime.Now().Add(time.Duration(-1*offset) * time.Second)},
+			FinalizedFetcher:      &mock.ChainService{CurrentJustifiedCheckPoint: justifiedCheckpoint},
+			OptimisticModeFetcher: &mock.ChainService{Optimistic: false},
 		},
 	}
 

beacon-chain/rpc/service.go

@@ -296,7 +296,7 @@ func (s *Service) initializeDebugServerRoutes(debugServer *debug.Server) {
 	s.cfg.Router.HandleFunc("/eth/v1/debug/beacon/states/{state_id}", debugServer.GetBeaconStateSSZ).Methods(http.MethodGet)
 	s.cfg.Router.HandleFunc("/eth/v2/debug/beacon/states/{state_id}", debugServer.GetBeaconStateV2).Methods(http.MethodGet)
 	s.cfg.Router.HandleFunc("/eth/v2/debug/beacon/heads", debugServer.GetForkChoiceHeadsV2).Methods(http.MethodGet)
-	s.cfg.Router.HandleFunc("/eth/v2/debug/fork_choice", debugServer.GetForkChoice).Methods(http.MethodGet)
+	s.cfg.Router.HandleFunc("/eth/v1/debug/fork_choice", debugServer.GetForkChoice).Methods(http.MethodGet)
 }
 
 // prysm internal routes
@@ -359,16 +359,17 @@ func (s *Service) Start() {
 	})
 
 	coreService := &core.Service{
-		HeadFetcher:        s.cfg.HeadFetcher,
-		GenesisTimeFetcher: s.cfg.GenesisTimeFetcher,
-		SyncChecker:        s.cfg.SyncService,
-		Broadcaster:        s.cfg.Broadcaster,
-		SyncCommitteePool:  s.cfg.SyncCommitteeObjectPool,
-		OperationNotifier:  s.cfg.OperationNotifier,
-		AttestationCache:   cache.NewAttestationCache(),
-		StateGen:           s.cfg.StateGen,
-		P2P:                s.cfg.Broadcaster,
-		FinalizedFetcher:   s.cfg.FinalizationFetcher,
+		HeadFetcher:           s.cfg.HeadFetcher,
+		GenesisTimeFetcher:    s.cfg.GenesisTimeFetcher,
+		SyncChecker:           s.cfg.SyncService,
+		Broadcaster:           s.cfg.Broadcaster,
+		SyncCommitteePool:     s.cfg.SyncCommitteeObjectPool,
+		OperationNotifier:     s.cfg.OperationNotifier,
+		AttestationCache:      cache.NewAttestationCache(),
+		StateGen:              s.cfg.StateGen,
+		P2P:                   s.cfg.Broadcaster,
+		FinalizedFetcher:      s.cfg.FinalizationFetcher,
+		OptimisticModeFetcher: s.cfg.OptimisticModeFetcher,
 	}
 
 	validatorServer := &validatorv1alpha1.Server{

beacon-chain/rpc/service_test.go

@@ -36,6 +36,18 @@ func init() {
 	logrus.SetOutput(io.Discard)
 }
 
+func combineMaps(maps ...map[string][]string) map[string][]string {
+	combinedMap := make(map[string][]string)
+
+	for _, m := range maps {
+		for k, v := range m {
+			combinedMap[k] = v
+		}
+	}
+
+	return combinedMap
+}
+
 func TestServer_InitializeRoutes(t *testing.T) {
 	s := Service{
 		cfg: &Config{
@@ -58,80 +70,106 @@ func TestServer_InitializeRoutes(t *testing.T) {
 	s.initializePrysmNodeServerRoutes(&nodeprysm.Server{})
 	s.initializePrysmValidatorServerRoutes(&validatorprysm.Server{})
 
-	wantRouteList := map[string][]string{
-		"/eth/v1/beacon/rewards/blocks/{block_id}":                   {http.MethodGet},
-		"/eth/v1/beacon/rewards/attestations/{epoch}":                {http.MethodPost},
-		"/eth/v1/beacon/rewards/sync_committee/{block_id}":           {http.MethodPost},
-		"/eth/v1/builder/states/{state_id}/expected_withdrawals":     {http.MethodGet},
-		"/eth/v1/beacon/blob_sidecars/{block_id}":                    {http.MethodGet},
-		"/eth/v1/validator/aggregate_attestation":                    {http.MethodGet},
-		"/eth/v1/validator/contribution_and_proofs":                  {http.MethodPost},
-		"/eth/v1/validator/aggregate_and_proofs":                     {http.MethodPost},
-		"/eth/v1/validator/sync_committee_contribution":              {http.MethodGet},
-		"/eth/v1/validator/sync_committee_subscriptions":             {http.MethodPost},
-		"/eth/v1/validator/beacon_committee_subscriptions":           {http.MethodPost},
-		"/eth/v1/validator/attestation_data":                         {http.MethodGet},
-		"/eth/v1/validator/register_validator":                       {http.MethodPost},
-		"/eth/v1/validator/duties/attester/{epoch}":                  {http.MethodPost},
-		"/eth/v1/validator/duties/proposer/{epoch}":                  {http.MethodGet},
-		"/eth/v1/validator/duties/sync/{epoch}":                      {http.MethodPost},
-		"/eth/v1/validator/prepare_beacon_proposer":                  {http.MethodPost},
-		"/eth/v1/validator/liveness/{epoch}":                         {http.MethodPost},
-		"/eth/v2/validator/blocks/{slot}":                            {http.MethodGet},
-		"/eth/v1/validator/blinded_blocks/{slot}":                    {http.MethodGet},
-		"/eth/v3/validator/blocks/{slot}":                            {http.MethodGet},
-		"/eth/v1/node/syncing":                                       {http.MethodGet},
-		"/eth/v1/node/identity":                                      {http.MethodGet},
-		"/eth/v1/node/peers/{peer_id}":                               {http.MethodGet},
-		"/eth/v1/node/peers":                                         {http.MethodGet},
-		"/eth/v1/node/peer_count":                                    {http.MethodGet},
-		"/eth/v1/node/version":                                       {http.MethodGet},
-		"/eth/v1/node/health":                                        {http.MethodGet},
-		"/eth/v1/beacon/states/{state_id}/committees":                {http.MethodGet},
-		"/eth/v1/beacon/states/{state_id}/fork":                      {http.MethodGet},
-		"/eth/v1/beacon/states/{state_id}/root":                      {http.MethodGet},
-		"/eth/v1/beacon/states/{state_id}/sync_committees":           {http.MethodGet},
-		"/eth/v1/beacon/states/{state_id}/randao":                    {http.MethodGet},
-		"/eth/v1/beacon/blocks":                                      {http.MethodPost},
-		"/eth/v1/beacon/blinded_blocks":                              {http.MethodPost},
-		"/eth/v2/beacon/blocks":                                      {http.MethodPost},
-		"/eth/v2/beacon/blinded_blocks":                              {http.MethodPost},
-		"/eth/v1/beacon/blocks/{block_id}":                           {http.MethodGet},
-		"/eth/v2/beacon/blocks/{block_id}":                           {http.MethodGet},
-		"/eth/v1/beacon/blocks/{block_id}/attestations":              {http.MethodGet},
-		"/eth/v1/beacon/blinded_blocks/{block_id}":                   {http.MethodGet},
-		"/eth/v1/beacon/blocks/{block_id}/root":                      {http.MethodGet},
-		"/eth/v1/beacon/pool/attestations":                           {http.MethodGet, http.MethodPost},
-		"/eth/v1/beacon/pool/voluntary_exits":                        {http.MethodGet, http.MethodPost},
-		"/eth/v1/beacon/pool/sync_committees":                        {http.MethodPost},
-		"/eth/v1/beacon/pool/bls_to_execution_changes":               {http.MethodGet, http.MethodPost},
-		"/eth/v1/beacon/pool/attester_slashings":                     {http.MethodGet, http.MethodPost},
-		"/eth/v1/beacon/pool/proposer_slashings":                     {http.MethodGet, http.MethodPost},
-		"/eth/v1/beacon/headers":                                     {http.MethodGet},
-		"/eth/v1/beacon/headers/{block_id}":                          {http.MethodGet},
+	beaconRoutes := map[string][]string{
 		"/eth/v1/beacon/genesis":                                     {http.MethodGet},
+		"/eth/v1/beacon/states/{state_id}/root":                      {http.MethodGet},
+		"/eth/v1/beacon/states/{state_id}/fork":                      {http.MethodGet},
 		"/eth/v1/beacon/states/{state_id}/finality_checkpoints":      {http.MethodGet},
 		"/eth/v1/beacon/states/{state_id}/validators":                {http.MethodGet, http.MethodPost},
 		"/eth/v1/beacon/states/{state_id}/validators/{validator_id}": {http.MethodGet},
 		"/eth/v1/beacon/states/{state_id}/validator_balances":        {http.MethodGet, http.MethodPost},
-		"/eth/v1/config/deposit_contract":                            {http.MethodGet},
-		"/eth/v1/config/fork_schedule":                               {http.MethodGet},
-		"/eth/v1/config/spec":                                        {http.MethodGet},
-		"/eth/v1/events":                                             {http.MethodGet},
-		"/eth/v1/beacon/light_client/bootstrap/{block_root}":         {http.MethodGet},
-		"/eth/v1/beacon/light_client/updates":                        {http.MethodGet},
-		"/eth/v1/beacon/light_client/finality_update":                {http.MethodGet},
-		"/eth/v1/beacon/light_client/optimistic_update":              {http.MethodGet},
-		"/eth/v1/debug/beacon/states/{state_id}":                     {http.MethodGet},
-		"/eth/v2/debug/beacon/states/{state_id}":                     {http.MethodGet},
-		"/eth/v2/debug/beacon/heads":                                 {http.MethodGet},
-		"/eth/v2/debug/fork_choice":                                  {http.MethodGet},
-		"/prysm/v1/beacon/weak_subjectivity":                         {http.MethodGet},
-		"/prysm/node/trusted_peers":                                  {http.MethodGet, http.MethodPost},
-		"/prysm/node/trusted_peers/{peer_id}":                        {http.MethodDelete},
-		"/prysm/validators/performance":                              {http.MethodPost},
-		"/eth/v1/beacon/states/{state_id}/validator_count":           {http.MethodGet},
+		"/eth/v1/beacon/states/{state_id}/committees":                {http.MethodGet},
+		"/eth/v1/beacon/states/{state_id}/sync_committees":           {http.MethodGet},
+		"/eth/v1/beacon/states/{state_id}/randao":                    {http.MethodGet},
+		"/eth/v1/beacon/headers":                                     {http.MethodGet},
+		"/eth/v1/beacon/headers/{block_id}":                          {http.MethodGet},
+		"/eth/v1/beacon/blinded_blocks":                              {http.MethodPost},
+		"/eth/v2/beacon/blinded_blocks":                              {http.MethodPost},
+		"/eth/v1/beacon/blocks":                                      {http.MethodPost},
+		"/eth/v2/beacon/blocks":                                      {http.MethodPost},
+		"/eth/v1/beacon/blocks/{block_id}":                           {http.MethodGet}, //deprecated
+		"/eth/v2/beacon/blocks/{block_id}":                           {http.MethodGet},
+		"/eth/v1/beacon/blocks/{block_id}/root":                      {http.MethodGet},
+		"/eth/v1/beacon/blocks/{block_id}/attestations":              {http.MethodGet},
+		"/eth/v1/beacon/blob_sidecars/{block_id}":                    {http.MethodGet},
+		"/eth/v1/beacon/rewards/sync_committee/{block_id}":           {http.MethodPost},
+		//"/eth/v1/beacon/deposit_snapshot": {http.MethodGet}, not implemented
+		"/eth/v1/beacon/rewards/blocks/{block_id}":           {http.MethodGet},
+		"/eth/v1/beacon/rewards/attestations/{epoch}":        {http.MethodPost},
+		"/eth/v1/beacon/blinded_blocks/{block_id}":           {http.MethodGet},
+		"/eth/v1/beacon/light_client/bootstrap/{block_root}": {http.MethodGet},
+		"/eth/v1/beacon/light_client/updates":                {http.MethodGet},
+		"/eth/v1/beacon/light_client/finality_update":        {http.MethodGet},
+		"/eth/v1/beacon/light_client/optimistic_update":      {http.MethodGet},
+		"/eth/v1/beacon/pool/attestations":                   {http.MethodGet, http.MethodPost},
+		"/eth/v1/beacon/pool/attester_slashings":             {http.MethodGet, http.MethodPost},
+		"/eth/v1/beacon/pool/proposer_slashings":             {http.MethodGet, http.MethodPost},
+		"/eth/v1/beacon/pool/sync_committees":                {http.MethodPost},
+		"/eth/v1/beacon/pool/voluntary_exits":                {http.MethodGet, http.MethodPost},
+		"/eth/v1/beacon/pool/bls_to_execution_changes":       {http.MethodGet, http.MethodPost},
 	}
+
+	builderRoutes := map[string][]string{
+		"/eth/v1/builder/states/{state_id}/expected_withdrawals": {http.MethodGet},
+	}
+
+	configRoutes := map[string][]string{
+		"/eth/v1/config/fork_schedule":    {http.MethodGet},
+		"/eth/v1/config/spec":             {http.MethodGet},
+		"/eth/v1/config/deposit_contract": {http.MethodGet},
+	}
+
+	debugRoutes := map[string][]string{
+		"/eth/v1/debug/beacon/states/{state_id}": {http.MethodGet}, //deprecated
+		"/eth/v2/debug/beacon/states/{state_id}": {http.MethodGet},
+		"/eth/v2/debug/beacon/heads":             {http.MethodGet},
+		"/eth/v1/debug/fork_choice":              {http.MethodGet},
+	}
+
+	eventsRoutes := map[string][]string{
+		"/eth/v1/events": {http.MethodGet},
+	}
+
+	nodeRoutes := map[string][]string{
+		"/eth/v1/node/identity":        {http.MethodGet},
+		"/eth/v1/node/peers":           {http.MethodGet},
+		"/eth/v1/node/peers/{peer_id}": {http.MethodGet},
+		"/eth/v1/node/peer_count":      {http.MethodGet},
+		"/eth/v1/node/version":         {http.MethodGet},
+		"/eth/v1/node/syncing":         {http.MethodGet},
+		"/eth/v1/node/health":          {http.MethodGet},
+	}
+
+	validatorRoutes := map[string][]string{
+		"/eth/v1/validator/duties/attester/{epoch}":        {http.MethodPost},
+		"/eth/v1/validator/duties/proposer/{epoch}":        {http.MethodGet},
+		"/eth/v1/validator/duties/sync/{epoch}":            {http.MethodPost},
+		"/eth/v2/validator/blocks/{slot}":                  {http.MethodGet}, //deprecated
+		"/eth/v3/validator/blocks/{slot}":                  {http.MethodGet},
+		"/eth/v1/validator/blinded_blocks/{slot}":          {http.MethodGet}, //deprecated
+		"/eth/v1/validator/attestation_data":               {http.MethodGet},
+		"/eth/v1/validator/aggregate_attestation":          {http.MethodGet},
+		"/eth/v1/validator/aggregate_and_proofs":           {http.MethodPost},
+		"/eth/v1/validator/beacon_committee_subscriptions": {http.MethodPost},
+		"/eth/v1/validator/sync_committee_subscriptions":   {http.MethodPost},
+		//"/eth/v1/validator/beacon_committee_selections":   {http.MethodPost}, // not implemented
+		"/eth/v1/validator/sync_committee_contribution": {http.MethodGet},
+		//"/eth/v1/validator/sync_committee_selections":  {http.MethodPost}, // not implemented
+		"/eth/v1/validator/contribution_and_proofs": {http.MethodPost},
+		"/eth/v1/validator/prepare_beacon_proposer": {http.MethodPost},
+		"/eth/v1/validator/register_validator":      {http.MethodPost},
+		"/eth/v1/validator/liveness/{epoch}":        {http.MethodPost},
+	}
+
+	prysmCustomRoutes := map[string][]string{
+		"/prysm/v1/beacon/weak_subjectivity":               {http.MethodGet},
+		"/prysm/node/trusted_peers":                        {http.MethodGet, http.MethodPost},
+		"/prysm/node/trusted_peers/{peer_id}":              {http.MethodDelete},
+		"/prysm/validators/performance":                    {http.MethodPost},
+		"/eth/v1/beacon/states/{state_id}/validator_count": {http.MethodGet},
+	}
+
+	wantRouteList := combineMaps(beaconRoutes, builderRoutes, configRoutes, debugRoutes, eventsRoutes, nodeRoutes, validatorRoutes, prysmCustomRoutes)
 	gotRouteList := make(map[string][]string)
 	err := s.cfg.Router.Walk(func(route *mux.Route, router *mux.Router, ancestors []*mux.Route) error {
 		tpl, err1 := route.GetPathTemplate()

beacon-chain/state/interfaces.go

@@ -22,6 +22,7 @@ type BeaconState interface {
 	WriteOnlyBeaconState
 	Copy() BeaconState
 	CopyAllTries()
+	Defragment()
 	HashTreeRoot(ctx context.Context) ([32]byte, error)
 	Prover
 	json.Marshaler
@@ -120,6 +121,7 @@ type ReadOnlyValidators interface {
 	ValidatorAtIndex(idx primitives.ValidatorIndex) (*ethpb.Validator, error)
 	ValidatorAtIndexReadOnly(idx primitives.ValidatorIndex) (ReadOnlyValidator, error)
 	ValidatorIndexByPubkey(key [fieldparams.BLSPubkeyLength]byte) (primitives.ValidatorIndex, bool)
+	PublicKeys() ([][fieldparams.BLSPubkeyLength]byte, error)
 	PubkeyAtIndex(idx primitives.ValidatorIndex) [fieldparams.BLSPubkeyLength]byte
 	NumValidators() int
 	ReadFromEveryValidator(f func(idx int, val ReadOnlyValidator) error) error

beacon-chain/state/state-native/getters_validator.go

@@ -181,6 +181,27 @@ func (b *BeaconState) PubkeyAtIndex(idx primitives.ValidatorIndex) [fieldparams.
 	return bytesutil.ToBytes48(v.PublicKey)
 }
 
+// PublicKeys builds a list of all validator public keys, with each key's index aligned to its validator index.
+func (b *BeaconState) PublicKeys() ([][fieldparams.BLSPubkeyLength]byte, error) {
+	b.lock.RLock()
+	defer b.lock.RUnlock()
+
+	l := b.validatorsLen()
+	res := make([][fieldparams.BLSPubkeyLength]byte, l)
+	for i := 0; i < l; i++ {
+		if features.Get().EnableExperimentalState {
+			val, err := b.validatorsMultiValue.At(b, uint64(i))
+			if err != nil {
+				return nil, err
+			}
+			copy(res[i][:], val.PublicKey)
+		} else {
+			copy(res[i][:], b.validators[i].PublicKey)
+		}
+	}
+	return res, nil
+}
+
 // NumValidators returns the size of the validator registry.
 func (b *BeaconState) NumValidators() int {
 	b.lock.RLock()

beacon-chain/state/state-native/multi_value_slices.go

@@ -123,6 +123,55 @@ func NewMultiValueValidators(vals []*ethpb.Validator) *MultiValueValidators {
 	return mv
 }
 
+// Defragment checks whether each individual multi-value field in our state is fragmented
+// and if it is, it will 'reset' the field to create a new multivalue object.
+func (b *BeaconState) Defragment() {
+	b.lock.Lock()
+	defer b.lock.Unlock()
+	if b.blockRootsMultiValue != nil && b.blockRootsMultiValue.IsFragmented() {
+		initialMVslice := b.blockRootsMultiValue
+		b.blockRootsMultiValue = b.blockRootsMultiValue.Reset(b)
+		initialMVslice.Detach(b)
+		multiValueCountGauge.WithLabelValues(types.BlockRoots.String()).Inc()
+		runtime.SetFinalizer(b.blockRootsMultiValue, blockRootsFinalizer)
+	}
+	if b.stateRootsMultiValue != nil && b.stateRootsMultiValue.IsFragmented() {
+		initialMVslice := b.stateRootsMultiValue
+		b.stateRootsMultiValue = b.stateRootsMultiValue.Reset(b)
+		initialMVslice.Detach(b)
+		multiValueCountGauge.WithLabelValues(types.StateRoots.String()).Inc()
+		runtime.SetFinalizer(b.stateRootsMultiValue, stateRootsFinalizer)
+	}
+	if b.randaoMixesMultiValue != nil && b.randaoMixesMultiValue.IsFragmented() {
+		initialMVslice := b.randaoMixesMultiValue
+		b.randaoMixesMultiValue = b.randaoMixesMultiValue.Reset(b)
+		initialMVslice.Detach(b)
+		multiValueCountGauge.WithLabelValues(types.RandaoMixes.String()).Inc()
+		runtime.SetFinalizer(b.randaoMixesMultiValue, randaoMixesFinalizer)
+	}
+	if b.balancesMultiValue != nil && b.balancesMultiValue.IsFragmented() {
+		initialMVslice := b.balancesMultiValue
+		b.balancesMultiValue = b.balancesMultiValue.Reset(b)
+		initialMVslice.Detach(b)
+		multiValueCountGauge.WithLabelValues(types.Balances.String()).Inc()
+		runtime.SetFinalizer(b.balancesMultiValue, balancesFinalizer)
+	}
+	if b.validatorsMultiValue != nil && b.validatorsMultiValue.IsFragmented() {
+		initialMVslice := b.validatorsMultiValue
+		b.validatorsMultiValue = b.validatorsMultiValue.Reset(b)
+		initialMVslice.Detach(b)
+		multiValueCountGauge.WithLabelValues(types.Validators.String()).Inc()
+		runtime.SetFinalizer(b.validatorsMultiValue, validatorsFinalizer)
+	}
+	if b.inactivityScoresMultiValue != nil && b.inactivityScoresMultiValue.IsFragmented() {
+		initialMVslice := b.inactivityScoresMultiValue
+		b.inactivityScoresMultiValue = b.inactivityScoresMultiValue.Reset(b)
+		initialMVslice.Detach(b)
+		multiValueCountGauge.WithLabelValues(types.InactivityScores.String()).Inc()
+		runtime.SetFinalizer(b.inactivityScoresMultiValue, inactivityScoresFinalizer)
+	}
+}
+
 func randaoMixesFinalizer(m *MultiValueRandaoMixes) {
 	multiValueCountGauge.WithLabelValues(types.RandaoMixes.String()).Dec()
 }

beacon-chain/state/stategen/BUILD.bazel

@@ -31,7 +31,7 @@ go_library(
         "//beacon-chain/db/filters:go_default_library",
         "//beacon-chain/forkchoice:go_default_library",
         "//beacon-chain/state:go_default_library",
-        "//beacon-chain/sync/backfill:go_default_library",
+        "//beacon-chain/sync/backfill/coverage:go_default_library",
         "//cache/lru:go_default_library",
         "//config/params:go_default_library",
         "//consensus-types/blocks:go_default_library",

beacon-chain/state/stategen/getter.go

@@ -332,9 +332,8 @@ func (s *State) CombinedCache() *CombinedCache {
 }
 
 func (s *State) slotAvailable(slot primitives.Slot) bool {
-	// default to assuming node was initialized from genesis - backfill only needs to be specified for checkpoint sync
-	if s.backfillStatus == nil {
+	if s.avb == nil {
 		return true
 	}
-	return s.backfillStatus.SlotCovered(slot)
+	return s.avb.AvailableBlock(slot)
 }

beacon-chain/state/stategen/service.go

@@ -13,7 +13,7 @@ import (
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/db"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/forkchoice"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/state"
-	"github.com/prysmaticlabs/prysm/v4/beacon-chain/sync/backfill"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/sync/backfill/coverage"
 	"github.com/prysmaticlabs/prysm/v4/config/params"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v4/crypto/bls"
@@ -51,7 +51,7 @@ type State struct {
 	finalizedInfo           *finalizedInfo
 	epochBoundaryStateCache *epochBoundaryState
 	saveHotStateDB          *saveHotStateDbConfig
-	backfillStatus          *backfill.Status
+	avb                     coverage.AvailableBlocker
 	migrationLock           *sync.Mutex
 	fc                      forkchoice.ForkChoicer
 }
@@ -78,9 +78,11 @@ type finalizedInfo struct {
 // Option is a functional option for controlling the initialization of a *State value
 type Option func(*State)
 
-func WithBackfillStatus(bfs *backfill.Status) Option {
+// WithAvailableBlocker gives stategen an AvailableBlocker, which is used to determine if a given
+// block is available. This is necessary because backfill creates a hole in the block history.
+func WithAvailableBlocker(avb coverage.AvailableBlocker) Option {
 	return func(sg *State) {
-		sg.backfillStatus = bfs
+		sg.avb = avb
 	}
 }
 

beacon-chain/sync/backfill/BUILD.bazel

@@ -2,30 +2,78 @@ load("@prysm//tools/go:def.bzl", "go_library", "go_test")
 
 go_library(
     name = "go_default_library",
-    srcs = ["status.go"],
+    srcs = [
+        "batch.go",
+        "batcher.go",
+        "metrics.go",
+        "pool.go",
+        "service.go",
+        "status.go",
+        "verify.go",
+        "worker.go",
+    ],
     importpath = "github.com/prysmaticlabs/prysm/v4/beacon-chain/sync/backfill",
     visibility = ["//visibility:public"],
     deps = [
+        "//beacon-chain/core/helpers:go_default_library",
+        "//beacon-chain/core/signing:go_default_library",
         "//beacon-chain/db:go_default_library",
+        "//beacon-chain/p2p:go_default_library",
+        "//beacon-chain/p2p/peers:go_default_library",
+        "//beacon-chain/startup:go_default_library",
+        "//beacon-chain/state:go_default_library",
+        "//beacon-chain/sync:go_default_library",
+        "//config/fieldparams:go_default_library",
+        "//config/params:go_default_library",
         "//consensus-types/blocks:go_default_library",
         "//consensus-types/interfaces:go_default_library",
         "//consensus-types/primitives:go_default_library",
+        "//crypto/bls:go_default_library",
+        "//encoding/bytesutil:go_default_library",
+        "//network/forks:go_default_library",
+        "//proto/dbval:go_default_library",
+        "//proto/prysm/v1alpha1:go_default_library",
+        "//runtime:go_default_library",
+        "//time/slots:go_default_library",
+        "@com_github_libp2p_go_libp2p//core/peer: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_sirupsen_logrus//:go_default_library",
     ],
 )
 
 go_test(
     name = "go_default_test",
-    srcs = ["status_test.go"],
+    srcs = [
+        "batcher_test.go",
+        "pool_test.go",
+        "service_test.go",
+        "status_test.go",
+        "verify_test.go",
+    ],
     embed = [":go_default_library"],
     deps = [
+        "//beacon-chain/core/signing:go_default_library",
+        "//beacon-chain/db:go_default_library",
+        "//beacon-chain/p2p/testing:go_default_library",
+        "//beacon-chain/startup:go_default_library",
+        "//beacon-chain/state:go_default_library",
+        "//config/fieldparams:go_default_library",
         "//config/params:go_default_library",
         "//consensus-types/blocks:go_default_library",
         "//consensus-types/blocks/testing:go_default_library",
         "//consensus-types/interfaces:go_default_library",
         "//consensus-types/primitives:go_default_library",
+        "//crypto/bls:go_default_library",
+        "//encoding/bytesutil:go_default_library",
+        "//network/forks:go_default_library",
+        "//proto/dbval:go_default_library",
+        "//runtime/interop:go_default_library",
         "//testing/require:go_default_library",
         "//testing/util: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",
     ],
 )

beacon-chain/sync/backfill/batch.go

@@ -0,0 +1,141 @@
+package backfill
+
+import (
+	"fmt"
+	"time"
+
+	"github.com/libp2p/go-libp2p/core/peer"
+	"github.com/pkg/errors"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
+	eth "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
+	log "github.com/sirupsen/logrus"
+)
+
+// ErrChainBroken indicates a backfill batch can't be imported to the db because it is not known to be the ancestor
+// of the canonical chain.
+var ErrChainBroken = errors.New("batch is not the ancestor of a known finalized root")
+
+type batchState int
+
+func (s batchState) String() string {
+	switch s {
+	case batchNil:
+		return "nil"
+	case batchInit:
+		return "init"
+	case batchSequenced:
+		return "sequenced"
+	case batchErrRetryable:
+		return "error_retryable"
+	case batchImportable:
+		return "importable"
+	case batchImportComplete:
+		return "import_complete"
+	case batchEndSequence:
+		return "end_sequence"
+	default:
+		return "unknown"
+	}
+}
+
+const (
+	batchNil batchState = iota
+	batchInit
+	batchSequenced
+	batchErrRetryable
+	batchImportable
+	batchImportComplete
+	batchEndSequence
+)
+
+type batchId string
+
+type batch struct {
+	firstScheduled time.Time
+	scheduled      time.Time
+	seq            int // sequence identifier, ie how many times has the sequence() method served this batch
+	retries        int
+	begin          primitives.Slot
+	end            primitives.Slot // half-open interval, [begin, end), ie >= start, < end.
+	results        VerifiedROBlocks
+	err            error
+	state          batchState
+	pid            peer.ID
+}
+
+func (b batch) logFields() log.Fields {
+	return map[string]interface{}{
+		"batch_id":  b.id(),
+		"state":     b.state.String(),
+		"scheduled": b.scheduled.String(),
+		"seq":       b.seq,
+		"retries":   b.retries,
+		"begin":     b.begin,
+		"end":       b.end,
+		"pid":       b.pid,
+	}
+}
+
+func (b batch) replaces(r batch) bool {
+	if r.state == batchImportComplete {
+		return false
+	}
+	if b.begin != r.begin {
+		return false
+	}
+	if b.end != r.end {
+		return false
+	}
+	return b.seq >= r.seq
+}
+
+func (b batch) id() batchId {
+	return batchId(fmt.Sprintf("%d:%d", b.begin, b.end))
+}
+
+func (b batch) ensureParent(expected [32]byte) error {
+	tail := b.results[len(b.results)-1]
+	if tail.Root() != expected {
+		return errors.Wrapf(ErrChainBroken, "last parent_root=%#x, tail root=%#x", expected, tail.Root())
+	}
+	return nil
+}
+
+func (b batch) request() *eth.BeaconBlocksByRangeRequest {
+	return &eth.BeaconBlocksByRangeRequest{
+		StartSlot: b.begin,
+		Count:     uint64(b.end - b.begin),
+		Step:      1,
+	}
+}
+
+func (b batch) withState(s batchState) batch {
+	if s == batchSequenced {
+		b.scheduled = time.Now()
+		switch b.state {
+		case batchErrRetryable:
+			b.retries += 1
+			log.WithFields(b.logFields()).Info("sequencing batch for retry")
+		case batchInit, batchNil:
+			b.firstScheduled = b.scheduled
+		}
+	}
+	if s == batchImportComplete {
+		backfillBatchTimeRoundtrip.Observe(float64(time.Since(b.firstScheduled).Milliseconds()))
+		log.WithFields(b.logFields()).Debug("Backfill batch imported.")
+	}
+	b.state = s
+	b.seq += 1
+	return b
+}
+
+func (b batch) withPeer(p peer.ID) batch {
+	b.pid = p
+	backfillBatchTimeWaiting.Observe(float64(time.Since(b.scheduled).Milliseconds()))
+	return b
+}
+
+func (b batch) withRetryableError(err error) batch {
+	b.err = err
+	return b.withState(batchErrRetryable)
+}

beacon-chain/sync/backfill/batcher.go

@@ -0,0 +1,197 @@
+package backfill
+
+import (
+	"github.com/pkg/errors"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
+)
+
+var errMaxBatches = errors.New("backfill batch requested in excess of max outstanding batches")
+var errEndSequence = errors.New("sequence has terminated, no more backfill batches will be produced")
+var errCannotDecreaseMinimum = errors.New("the minimum backfill slot can only be increased, not decreased")
+
+type batchSequencer struct {
+	batcher batcher
+	seq     []batch
+}
+
+// sequence() is meant as a verb "arrange in a particular order".
+// sequence determines the next set of batches that should be worked on based on the state of the batches
+// in its internal view. sequence relies on update() for updates to its view of the
+// batches it has previously sequenced.
+func (c *batchSequencer) sequence() ([]batch, error) {
+	s := make([]batch, 0)
+	// batch start slots are in descending order, c.seq[n].begin == c.seq[n+1].end
+	for i := range c.seq {
+		switch c.seq[i].state {
+		case batchInit, batchErrRetryable:
+			c.seq[i] = c.seq[i].withState(batchSequenced)
+			s = append(s, c.seq[i])
+		case batchNil:
+			// batchNil is the zero value of the batch type.
+			// This case means that we are initializing a batch that was created by the
+			// initial allocation of the seq slice, so batcher need to compute its bounds.
+			var b batch
+			if i == 0 {
+				// The first item in the list is a special case, subsequent items are initialized
+				// relative to the preceding batches.
+				b = c.batcher.before(c.batcher.max)
+			} else {
+				b = c.batcher.beforeBatch(c.seq[i-1])
+			}
+			c.seq[i] = b.withState(batchSequenced)
+			s = append(s, c.seq[i])
+		case batchEndSequence:
+			if len(s) == 0 {
+				s = append(s, c.seq[i])
+			}
+		default:
+			continue
+		}
+	}
+	if len(s) == 0 {
+		return nil, errMaxBatches
+	}
+
+	return s, nil
+}
+
+// update serves 2 roles.
+//   - updating batchSequencer's copy of the given batch.
+//   - removing batches that are completely imported from the sequence,
+//     so that they are not returned the next time import() is called, and populating
+//     seq with new batches that are ready to be worked on.
+func (c *batchSequencer) update(b batch) {
+	done := 0
+	for i := 0; i < len(c.seq); i++ {
+		if b.replaces(c.seq[i]) {
+			c.seq[i] = b
+		}
+		// Assumes invariant that batches complete and update is called in order.
+		// This should be true because the code using the sequencer doesn't know the expected parent
+		// for a batch until it imports the previous batch.
+		if c.seq[i].state == batchImportComplete {
+			done += 1
+			continue
+		}
+		// Move the unfinished batches to overwrite the finished ones.
+		// eg consider [a,b,c,d,e] where a,b are done
+		// when i==2, done==2 (since done was incremented for a and b)
+		// so we want to copy c to a, then on i=3, d to b, then on i=4 e to c.
+		c.seq[i-done] = c.seq[i]
+	}
+	// Overwrite the moved batches with the next ones in the sequence.
+	// Continuing the example in the comment above, len(c.seq)==5, done=2, so i=3.
+	// We want to replace index 3 with the batch that should be processed after index 2,
+	// which was previously the earliest known batch, and index 4 with the batch that should
+	// be processed after index 3, the new earliest batch.
+	for i := len(c.seq) - done; i < len(c.seq); i++ {
+		c.seq[i] = c.batcher.beforeBatch(c.seq[i-1])
+	}
+}
+
+// importable returns all batches that are ready to be imported. This means they satisfy 2 conditions:
+//   - They are in state batchImportable, which means their data has been downloaded and proposer signatures have been verified.
+//   - There are no batches that are not in state batchImportable between them and the start of the slice. This ensures that they
+//     can be connected to the canonical chain, either because the root of the last block in the batch matches the parent_root of
+//     the oldest block in the canonical chain, or because the root of the last block in the batch matches the parent_root of the
+//     new block preceding them in the slice (which must connect to the batch before it, or to the canonical chain if it is first).
+func (c *batchSequencer) importable() []batch {
+	imp := make([]batch, 0)
+	for i := range c.seq {
+		if c.seq[i].state == batchImportable {
+			imp = append(imp, c.seq[i])
+			continue
+		}
+		// as soon as we hit a batch with a different state, we return everything leading to it.
+		// If the first element isn't importable, we'll return an empty slice.
+		break
+	}
+	return imp
+}
+
+// moveMinimum enables the backfill service to change the slot where the batcher will start replying with
+// batch state batchEndSequence (signaling that no new batches will be produced). This is done in response to
+// epochs advancing, which shrinks the gap between <checkpoint slot> and <current slot>-MIN_EPOCHS_FOR_BLOCK_REQUESTS,
+// allowing the node to download a smaller number of blocks.
+func (c *batchSequencer) moveMinimum(min primitives.Slot) error {
+	if min < c.batcher.min {
+		return errCannotDecreaseMinimum
+	}
+	c.batcher.min = min
+	return nil
+}
+
+// countWithState provides a view into how many batches are in a particular state
+// to be used for logging or metrics purposes.
+func (c *batchSequencer) countWithState(s batchState) int {
+	n := 0
+	for i := 0; i < len(c.seq); i++ {
+		if c.seq[i].state == s {
+			n += 1
+		}
+	}
+	return n
+}
+
+// numTodo computes the number of remaining batches for metrics and logging purposes.
+func (c *batchSequencer) numTodo() int {
+	if len(c.seq) == 0 {
+		return 0
+	}
+	lowest := c.seq[len(c.seq)-1]
+	todo := 0
+	if lowest.state != batchEndSequence {
+		todo = c.batcher.remaining(lowest.begin)
+	}
+	for _, b := range c.seq {
+		switch b.state {
+		case batchEndSequence, batchImportComplete, batchNil:
+			continue
+		default:
+			todo += 1
+		}
+	}
+	return todo
+}
+
+func newBatchSequencer(seqLen int, min, max, size primitives.Slot) *batchSequencer {
+	b := batcher{min: min, max: max, size: size}
+	seq := make([]batch, seqLen)
+	return &batchSequencer{batcher: b, seq: seq}
+}
+
+type batcher struct {
+	min  primitives.Slot
+	max  primitives.Slot
+	size primitives.Slot
+}
+
+func (r batcher) remaining(upTo primitives.Slot) int {
+	if r.min >= upTo {
+		return 0
+	}
+	delta := upTo - r.min
+	if delta%r.size != 0 {
+		return int(delta/r.size) + 1
+	}
+	return int(delta / r.size)
+}
+
+func (r batcher) beforeBatch(upTo batch) batch {
+	return r.before(upTo.begin)
+}
+
+func (r batcher) before(upTo primitives.Slot) batch {
+	// upTo is an exclusive upper bound. Requesting a batch before the lower bound of backfill signals the end of the
+	// backfill process.
+	if upTo <= r.min {
+		return batch{begin: upTo, end: upTo, state: batchEndSequence}
+	}
+	begin := r.min
+	if upTo > r.size+r.min {
+		begin = upTo - r.size
+	}
+
+	// batch.end is exclusive, .begin is inclusive, so the prev.end = next.begin
+	return batch{begin: begin, end: upTo, state: batchInit}
+}

beacon-chain/sync/backfill/batcher_test.go

@@ -0,0 +1,208 @@
+package backfill
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/v4/testing/require"
+)
+
+func TestBatcherBefore(t *testing.T) {
+	cases := []struct {
+		name   string
+		b      batcher
+		upTo   []primitives.Slot
+		expect []batch
+	}{
+		{
+			name: "size 10",
+			b:    batcher{min: 0, size: 10},
+			upTo: []primitives.Slot{33, 30, 10, 6},
+			expect: []batch{
+				{begin: 23, end: 33, state: batchInit},
+				{begin: 20, end: 30, state: batchInit},
+				{begin: 0, end: 10, state: batchInit},
+				{begin: 0, end: 6, state: batchInit},
+			},
+		},
+		{
+			name: "size 4",
+			b:    batcher{min: 0, size: 4},
+			upTo: []primitives.Slot{33, 6, 4},
+			expect: []batch{
+				{begin: 29, end: 33, state: batchInit},
+				{begin: 2, end: 6, state: batchInit},
+				{begin: 0, end: 4, state: batchInit},
+			},
+		},
+		{
+			name: "trigger end",
+			b:    batcher{min: 20, size: 10},
+			upTo: []primitives.Slot{33, 30, 25, 21, 20, 19},
+			expect: []batch{
+				{begin: 23, end: 33, state: batchInit},
+				{begin: 20, end: 30, state: batchInit},
+				{begin: 20, end: 25, state: batchInit},
+				{begin: 20, end: 21, state: batchInit},
+				{begin: 20, end: 20, state: batchEndSequence},
+				{begin: 19, end: 19, state: batchEndSequence},
+			},
+		},
+	}
+	for _, c := range cases {
+		for i := range c.upTo {
+			upTo := c.upTo[i]
+			expect := c.expect[i]
+			t.Run(fmt.Sprintf("%s upTo %d", c.name, upTo), func(t *testing.T) {
+				got := c.b.before(upTo)
+				require.Equal(t, expect.begin, got.begin)
+				require.Equal(t, expect.end, got.end)
+				require.Equal(t, expect.state, got.state)
+			})
+		}
+	}
+}
+
+func TestBatchSequencer(t *testing.T) {
+	var min, max, size primitives.Slot
+	seqLen := 8
+	min = 0
+	max = 11235
+	size = 64
+	seq := newBatchSequencer(seqLen, min, max, size)
+	expected := []batch{
+		{begin: 11171, end: 11235},
+		{begin: 11107, end: 11171},
+		{begin: 11043, end: 11107},
+		{begin: 10979, end: 11043},
+		{begin: 10915, end: 10979},
+		{begin: 10851, end: 10915},
+		{begin: 10787, end: 10851},
+		{begin: 10723, end: 10787},
+	}
+	got, err := seq.sequence()
+	require.Equal(t, seqLen, len(got))
+	for i := 0; i < seqLen; i++ {
+		g := got[i]
+		exp := expected[i]
+		require.NoError(t, err)
+		require.Equal(t, exp.begin, g.begin)
+		require.Equal(t, exp.end, g.end)
+		require.Equal(t, batchSequenced, g.state)
+	}
+	// This should give us the error indicating there are too many outstanding batches.
+	_, err = seq.sequence()
+	require.ErrorIs(t, err, errMaxBatches)
+
+	// mark the last batch completed so we can call sequence again.
+	last := seq.seq[len(seq.seq)-1]
+	// With this state, the batch should get served back to us as the next batch.
+	last.state = batchErrRetryable
+	seq.update(last)
+	nextS, err := seq.sequence()
+	require.Equal(t, 1, len(nextS))
+	next := nextS[0]
+	require.NoError(t, err)
+	require.Equal(t, last.begin, next.begin)
+	require.Equal(t, last.end, next.end)
+	// sequence() should replace the batchErrRetryable state with batchSequenced.
+	require.Equal(t, batchSequenced, next.state)
+
+	// No batches have been marked importable.
+	require.Equal(t, 0, len(seq.importable()))
+
+	// Mark our batch importable and make sure it shows up in the list of importable batches.
+	next.state = batchImportable
+	seq.update(next)
+	require.Equal(t, 0, len(seq.importable()))
+	first := seq.seq[0]
+	first.state = batchImportable
+	seq.update(first)
+	require.Equal(t, 1, len(seq.importable()))
+	require.Equal(t, len(seq.seq), seqLen)
+	// change the last element back to batchInit so that the importable test stays simple
+	last = seq.seq[len(seq.seq)-1]
+	last.state = batchInit
+	seq.update(last)
+	// ensure that the number of importable elements grows as the list is marked importable
+	for i := 0; i < len(seq.seq); i++ {
+		seq.seq[i].state = batchImportable
+		require.Equal(t, i+1, len(seq.importable()))
+	}
+	// reset everything to init
+	for i := 0; i < len(seq.seq); i++ {
+		seq.seq[i].state = batchInit
+		require.Equal(t, 0, len(seq.importable()))
+	}
+	// loop backwards and make sure importable is zero until the first element is importable
+	for i := len(seq.seq) - 1; i > 0; i-- {
+		seq.seq[i].state = batchImportable
+		require.Equal(t, 0, len(seq.importable()))
+	}
+	seq.seq[0].state = batchImportable
+	require.Equal(t, len(seq.seq), len(seq.importable()))
+
+	// reset everything to init again
+	for i := 0; i < len(seq.seq); i++ {
+		seq.seq[i].state = batchInit
+		require.Equal(t, 0, len(seq.importable()))
+	}
+	// set first 3 elements to importable. we should see them in the result for importable()
+	// and be able to use update to cycle them away.
+	seq.seq[0].state, seq.seq[1].state, seq.seq[2].state = batchImportable, batchImportable, batchImportable
+	require.Equal(t, 3, len(seq.importable()))
+	a, b, c, z := seq.seq[0], seq.seq[1], seq.seq[2], seq.seq[3]
+	require.NotEqual(t, z.begin, seq.seq[2].begin)
+	require.NotEqual(t, z.begin, seq.seq[1].begin)
+	require.NotEqual(t, z.begin, seq.seq[0].begin)
+	a.state, b.state, c.state = batchImportComplete, batchImportComplete, batchImportComplete
+	seq.update(a)
+
+	// follow z as it moves down  the chain to the first spot
+	require.Equal(t, z.begin, seq.seq[2].begin)
+	require.NotEqual(t, z.begin, seq.seq[1].begin)
+	require.NotEqual(t, z.begin, seq.seq[0].begin)
+	seq.update(b)
+	require.NotEqual(t, z.begin, seq.seq[2].begin)
+	require.Equal(t, z.begin, seq.seq[1].begin)
+	require.NotEqual(t, z.begin, seq.seq[0].begin)
+	seq.update(c)
+	require.NotEqual(t, z.begin, seq.seq[2].begin)
+	require.NotEqual(t, z.begin, seq.seq[1].begin)
+	require.Equal(t, z.begin, seq.seq[0].begin)
+
+	// Check integrity of begin/end alignment across the sequence.
+	// Also update all the states to sequenced for the convenience of the next test.
+	for i := 1; i < len(seq.seq); i++ {
+		require.Equal(t, seq.seq[i].end, seq.seq[i-1].begin)
+		// won't touch the first element, which is fine because it is marked complete below.
+		seq.seq[i].state = batchSequenced
+	}
+
+	// set the min for the batcher close to the lowest slot. This will force the next batch to be partial and the batch
+	// after that to be the final batch.
+	newMin := seq.seq[len(seq.seq)-1].begin - 30
+	seq.batcher.min = newMin
+	first = seq.seq[0]
+	first.state = batchImportComplete
+	// update() with a complete state will cause the sequence to be extended with an additional batch
+	seq.update(first)
+	lastS, err := seq.sequence()
+	last = lastS[0]
+	require.NoError(t, err)
+	require.Equal(t, newMin, last.begin)
+	require.Equal(t, seq.seq[len(seq.seq)-2].begin, last.end)
+
+	// Mark first batch done again, this time check that sequence() gives errEndSequence.
+	first = seq.seq[0]
+	first.state = batchImportComplete
+	// update() with a complete state will cause the sequence to be extended with an additional batch
+	seq.update(first)
+	endExp, err := seq.sequence()
+	require.NoError(t, err)
+	require.Equal(t, 1, len(endExp))
+	end := endExp[0]
+	//require.ErrorIs(t, err, errEndSequence)
+	require.Equal(t, batchEndSequence, end.state)
+}

beacon-chain/sync/backfill/coverage/BUILD.bazel

@@ -0,0 +1,9 @@
+load("@prysm//tools/go:def.bzl", "go_library")
+
+go_library(
+    name = "go_default_library",
+    srcs = ["coverage.go"],
+    importpath = "github.com/prysmaticlabs/prysm/v4/beacon-chain/sync/backfill/coverage",
+    visibility = ["//visibility:public"],
+    deps = ["//consensus-types/primitives:go_default_library"],
+)

beacon-chain/sync/backfill/coverage/coverage.go

@@ -0,0 +1,9 @@
+package coverage
+
+import "github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
+
+// AvailableBlocker can be used to check whether there is a finalized block in the db for the given slot.
+// This interface is typically fulfilled by backfill.Store.
+type AvailableBlocker interface {
+	AvailableBlock(primitives.Slot) bool
+}

beacon-chain/sync/backfill/metrics.go

@@ -0,0 +1,67 @@
+package backfill
+
+import (
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
+)
+
+var (
+	oldestBatch = promauto.NewGauge(
+		prometheus.GaugeOpts{
+			Name: "backfill_earliest_wip_slot",
+			Help: "Earliest slot that has been assigned to a worker.",
+		},
+	)
+	batchesWaiting = promauto.NewGauge(
+		prometheus.GaugeOpts{
+			Name: "backfill_importable_batches_waiting",
+			Help: "Number of batches that are ready to be imported once they can be connected to the existing chain.",
+		},
+	)
+	backfillRemainingBatches = promauto.NewGauge(
+		prometheus.GaugeOpts{
+			Name: "backfill_remaining_batches",
+			Help: "Backfill remaining batches.",
+		},
+	)
+	backfillBatchesImported = promauto.NewCounter(
+		prometheus.CounterOpts{
+			Name: "backfill_batches_imported",
+			Help: "Number of backfill batches downloaded and imported.",
+		},
+	)
+	backfillBatchApproximateBytes = promauto.NewCounter(
+		prometheus.CounterOpts{
+			Name: "backfill_batch_bytes_downloaded",
+			Help: "Count of bytes downloaded from peers",
+		},
+	)
+	backfillBatchTimeRoundtrip = promauto.NewHistogram(
+		prometheus.HistogramOpts{
+			Name:    "backfill_batch_time_roundtrip",
+			Help:    "Total time to import batch, from first scheduled to imported.",
+			Buckets: []float64{400, 800, 1600, 3200, 6400, 12800},
+		},
+	)
+	backfillBatchTimeWaiting = promauto.NewHistogram(
+		prometheus.HistogramOpts{
+			Name:    "backfill_batch_time_waiting",
+			Help:    "Time batch waited for a suitable peer.",
+			Buckets: []float64{50, 100, 300, 1000, 2000},
+		},
+	)
+	backfillBatchTimeDownloading = promauto.NewHistogram(
+		prometheus.HistogramOpts{
+			Name:    "backfill_batch_time_download",
+			Help:    "Time batch spent downloading blocks from peer.",
+			Buckets: []float64{100, 300, 1000, 2000, 4000, 8000},
+		},
+	)
+	backfillBatchTimeVerifying = promauto.NewHistogram(
+		prometheus.HistogramOpts{
+			Name:    "backfill_batch_time_verify",
+			Help:    "Time batch spent downloading blocks from peer.",
+			Buckets: []float64{100, 300, 1000, 2000, 4000, 8000},
+		},
+	)
+)

beacon-chain/sync/backfill/pool.go

@@ -0,0 +1,152 @@
+package backfill
+
+import (
+	"context"
+	"math"
+	"time"
+
+	"github.com/libp2p/go-libp2p/core/peer"
+	"github.com/pkg/errors"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/p2p"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/p2p/peers"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/startup"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
+	log "github.com/sirupsen/logrus"
+)
+
+type batchWorkerPool interface {
+	spawn(ctx context.Context, n int, clock *startup.Clock, a PeerAssigner, v *verifier)
+	todo(b batch)
+	complete() (batch, error)
+}
+
+type worker interface {
+	run(context.Context)
+}
+
+type newWorker func(id workerId, in, out chan batch, c *startup.Clock, v *verifier) worker
+
+func defaultNewWorker(p p2p.P2P) newWorker {
+	return func(id workerId, in, out chan batch, c *startup.Clock, v *verifier) worker {
+		return newP2pWorker(id, p, in, out, c, v)
+	}
+}
+
+type p2pBatchWorkerPool struct {
+	maxBatches  int
+	newWorker   newWorker
+	toWorkers   chan batch
+	fromWorkers chan batch
+	toRouter    chan batch
+	fromRouter  chan batch
+	shutdownErr chan error
+	endSeq      []batch
+	ctx         context.Context
+	cancel      func()
+}
+
+var _ batchWorkerPool = &p2pBatchWorkerPool{}
+
+func newP2PBatchWorkerPool(p p2p.P2P, maxBatches int) *p2pBatchWorkerPool {
+	nw := defaultNewWorker(p)
+	return &p2pBatchWorkerPool{
+		newWorker:   nw,
+		toRouter:    make(chan batch, maxBatches),
+		fromRouter:  make(chan batch, maxBatches),
+		toWorkers:   make(chan batch),
+		fromWorkers: make(chan batch),
+		maxBatches:  maxBatches,
+		shutdownErr: make(chan error),
+	}
+}
+
+func (p *p2pBatchWorkerPool) spawn(ctx context.Context, n int, c *startup.Clock, a PeerAssigner, v *verifier) {
+	p.ctx, p.cancel = context.WithCancel(ctx)
+	go p.batchRouter(a)
+	for i := 0; i < n; i++ {
+		go p.newWorker(workerId(i), p.toWorkers, p.fromWorkers, c, v).run(p.ctx)
+	}
+}
+
+func (p *p2pBatchWorkerPool) todo(b batch) {
+	// Intercept batchEndSequence batches so workers can remain unaware of this state.
+	// Workers don't know what to do with batchEndSequence batches. They are a signal to the pool that the batcher
+	// has stopped producing things for the workers to do and the pool is close to winding down. See complete()
+	// to understand how the pool manages the state where all workers are idle
+	// and all incoming batches signal end of sequence.
+	if b.state == batchEndSequence {
+		p.endSeq = append(p.endSeq, b)
+		return
+	}
+	p.toRouter <- b
+}
+
+func (p *p2pBatchWorkerPool) complete() (batch, error) {
+	if len(p.endSeq) == p.maxBatches {
+		return p.endSeq[0], errEndSequence
+	}
+
+	select {
+	case b := <-p.fromRouter:
+		return b, nil
+	case err := <-p.shutdownErr:
+		return batch{}, errors.Wrap(err, "fatal error from backfill worker pool")
+	case <-p.ctx.Done():
+		log.WithError(p.ctx.Err()).Info("p2pBatchWorkerPool context canceled, shutting down")
+		return batch{}, p.ctx.Err()
+	}
+}
+
+func (p *p2pBatchWorkerPool) batchRouter(pa PeerAssigner) {
+	busy := make(map[peer.ID]bool)
+	todo := make([]batch, 0)
+	rt := time.NewTicker(time.Second)
+	earliest := primitives.Slot(math.MaxUint64)
+	for {
+		select {
+		case b := <-p.toRouter:
+			todo = append(todo, b)
+		case <-rt.C:
+			// Worker assignments can fail if assignBatch can't find a suitable peer.
+			// This ticker exists to periodically break out of the channel select
+			// to retry failed assignments.
+		case b := <-p.fromWorkers:
+			pid := b.pid
+			busy[pid] = false
+			p.fromRouter <- b
+		case <-p.ctx.Done():
+			log.WithError(p.ctx.Err()).Info("p2pBatchWorkerPool context canceled, shutting down")
+			p.shutdown(p.ctx.Err())
+			return
+		}
+		if len(todo) == 0 {
+			continue
+		}
+		// Try to assign as many outstanding batches as possible to peers and feed the assigned batches to workers.
+		assigned, err := pa.Assign(busy, len(todo))
+		if err != nil {
+			if errors.Is(err, peers.ErrInsufficientSuitable) {
+				// Transient error resulting from insufficient number of connected peers. Leave batches in
+				// queue and get to them whenever the peer situation is resolved.
+				continue
+			}
+			p.shutdown(err)
+			return
+		}
+		for _, pid := range assigned {
+			busy[pid] = true
+			todo[0].pid = pid
+			p.toWorkers <- todo[0].withPeer(pid)
+			if todo[0].begin < earliest {
+				earliest = todo[0].begin
+				oldestBatch.Set(float64(earliest))
+			}
+			todo = todo[1:]
+		}
+	}
+}
+
+func (p *p2pBatchWorkerPool) shutdown(err error) {
+	p.cancel()
+	p.shutdownErr <- err
+}

beacon-chain/sync/backfill/pool_test.go

@@ -0,0 +1,78 @@
+package backfill
+
+import (
+	"context"
+	"testing"
+	"time"
+
+	"github.com/libp2p/go-libp2p/core/peer"
+	p2ptest "github.com/prysmaticlabs/prysm/v4/beacon-chain/p2p/testing"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/startup"
+	"github.com/prysmaticlabs/prysm/v4/testing/require"
+	"github.com/prysmaticlabs/prysm/v4/testing/util"
+)
+
+type mockAssigner struct {
+	err    error
+	assign []peer.ID
+}
+
+// Assign satisfies the PeerAssigner interface so that mockAssigner can be used in tests
+// in place of the concrete p2p implementation of PeerAssigner.
+func (m mockAssigner) Assign(busy map[peer.ID]bool, n int) ([]peer.ID, error) {
+	if m.err != nil {
+		return nil, m.err
+	}
+	return m.assign, nil
+}
+
+var _ PeerAssigner = &mockAssigner{}
+
+func TestPoolDetectAllEnded(t *testing.T) {
+	nw := 5
+	p2p := p2ptest.NewTestP2P(t)
+	ctx := context.Background()
+	ma := &mockAssigner{}
+	pool := newP2PBatchWorkerPool(p2p, nw)
+	st, err := util.NewBeaconState()
+	require.NoError(t, err)
+	keys, err := st.PublicKeys()
+	require.NoError(t, err)
+	v, err := newBackfillVerifier(st.GenesisValidatorsRoot(), keys)
+	require.NoError(t, err)
+	pool.spawn(ctx, nw, startup.NewClock(time.Now(), [32]byte{}), ma, v)
+	br := batcher{min: 10, size: 10}
+	endSeq := br.before(0)
+	require.Equal(t, batchEndSequence, endSeq.state)
+	for i := 0; i < nw; i++ {
+		pool.todo(endSeq)
+	}
+	b, err := pool.complete()
+	require.ErrorIs(t, err, errEndSequence)
+	require.Equal(t, b.end, endSeq.end)
+}
+
+type mockPool struct {
+	spawnCalled  []int
+	finishedChan chan batch
+	finishedErr  chan error
+	todoChan     chan batch
+}
+
+func (m *mockPool) spawn(_ context.Context, _ int, _ *startup.Clock, _ PeerAssigner, _ *verifier) {
+}
+
+func (m *mockPool) todo(b batch) {
+	m.todoChan <- b
+}
+
+func (m *mockPool) complete() (batch, error) {
+	select {
+	case b := <-m.finishedChan:
+		return b, nil
+	case err := <-m.finishedErr:
+		return batch{}, err
+	}
+}
+
+var _ batchWorkerPool = &mockPool{}