Change signature of testing helper

Add tests for the state diff migration path in MigrateToCold:
- TestMigrateToColdHdiff_CanUpdateFinalizedInfo: verifies finalized info updates
- TestMigrateToColdHdiff_SkipsSlotsNotInDiffTree: verifies non-diff-tree slots are skipped
- TestMigrateToColdHdiff_NoOpWhenFinalizedSlotNotAdvanced: verifies no-op behavior

The test helper InitStateDiffCacheForTesting is in a separate file with
//go:build testing tag, ensuring it's excluded from production builds but
available for tests via gotags = ["testing"] in Bazel.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.github/PULL_REQUEST_TEMPLATE.md

@@ -34,4 +34,5 @@ Fixes #
 
 - [ ] I have read [CONTRIBUTING.md](https://github.com/prysmaticlabs/prysm/blob/develop/CONTRIBUTING.md).
 - [ ] I have included a uniquely named [changelog fragment file](https://github.com/prysmaticlabs/prysm/blob/develop/CONTRIBUTING.md#maintaining-changelogmd).
-- [ ] I have added a description to this PR with sufficient context for reviewers to understand this PR.
+- [ ] I have added a description with sufficient context for reviewers to understand this PR.
+- [ ] I have tested that my changes work as expected and I added a testing plan to the PR description (if applicable). 

BUILD.bazel

@@ -193,6 +193,7 @@ nogo(
         "//tools/analyzers/featureconfig:go_default_library",
         "//tools/analyzers/gocognit:go_default_library",
         "//tools/analyzers/ineffassign:go_default_library",
+        "//tools/analyzers/httpwriter:go_default_library",
         "//tools/analyzers/interfacechecker:go_default_library",
         "//tools/analyzers/logcapitalization:go_default_library",
         "//tools/analyzers/logruswitherror:go_default_library",

CHANGELOG.md

@@ -4,6 +4,91 @@ All notable changes to this project will be documented in this file.
 
 The format is based on Keep a Changelog, and this project adheres to Semantic Versioning.
 
+## [v7.1.0](https://github.com/prysmaticlabs/prysm/compare/v7.0.0...v7.1.0) - 2025-12-10
+
+This release includes several key features/fixes. If you are running v7.0.0 then you should update to v7.0.1 or later and remove the flag `--disable-last-epoch-targets`. 
+
+Release highlights:
+
+- Backfill is now supported in Fulu. Backfill from checkpoint sync now supports data columns. Run with `--enable-backfill` when using checkpoint sync.
+- A new node configuration to custody enough data columns to reconstruct blobs. Use flag `--semi-supernode` to custody at least 50% of the data columns.
+- Critical fixes in attestation processing.
+
+A post mortem doc with full details on the mainnet attestation processing issue from December 4th is expected in the coming days. 
+
+### Added
+
+- add fulu support to light client processing. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15995)
+- Record data column gossip KZG batch verification latency in both the pooled worker and fallback paths so the `beacon_kzg_verification_data_column_batch_milliseconds` histogram reflects gossip traffic, annotated with `path` labels to distinguish the sources. [[PR]](https://github.com/prysmaticlabs/prysm/pull/16018)
+- Implement Gloas state. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15611)
+- Add initial configs for the state-diff feature. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15903)
+- Add kv functions for the state-diff feature. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15903)
+- Add supported version for fork versions. [[PR]](https://github.com/prysmaticlabs/prysm/pull/16030)
+- prometheus metric `gossip_attestation_verification_milliseconds` to track attestation gossip topic validation latency. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15785)
+- Integrate state-diff into `State()`. [[PR]](https://github.com/prysmaticlabs/prysm/pull/16033)
+- Implement Gloas fork support in consensus-types/blocks with factory methods, getters, setters, and proto handling. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15618)
+- Integrate state-diff into `HasState()`. [[PR]](https://github.com/prysmaticlabs/prysm/pull/16045)
+- Added `--semi-supernode` flag to custody half of a super node's datacolumn requirements but allowing for reconstruction for blob retrieval. [[PR]](https://github.com/prysmaticlabs/prysm/pull/16029)
+- Data column backfill. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15580)
+- Backfill metrics for columns: backfill_data_column_sidecar_downloaded, backfill_data_column_sidecar_downloaded_bytes, backfill_batch_columns_download_ms, backfill_batch_columns_verify_ms. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15580)
+- prometheus summary `gossip_data_column_sidecar_arrival_milliseconds` to track data column sidecar arrival latency since slot start. [[PR]](https://github.com/prysmaticlabs/prysm/pull/16099)
+
+### Changed
+
+- Improve readability in slashing import and remove duplicated code. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15957)
+- Use dependent root instead of target when possible. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15996)
+- Changed `--subscribe-all-data-subnets` flag to `--supernode` and aliased `--subscribe-all-data-subnets` for existing users. [[PR]](https://github.com/prysmaticlabs/prysm/pull/16012)
+- Use explicit slot component timing configs. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15999)
+- Downgraded log level from INFO to DEBUG on PrepareBeaconProposer updated fee recipients. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15998)
+- Change the logging behaviour of Updated fee recipients to only log count of validators at Debug level and all validator indices at Trace level. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15998)
+- Stop emitting payload attribute events during late block handling when we are not proposing the next slot. [[PR]](https://github.com/prysmaticlabs/prysm/pull/16026)
+- Initialize the `ExecutionRequests` field in gossip block map. [[PR]](https://github.com/prysmaticlabs/prysm/pull/16047)
+- Avoid redundant WithHttpEndpoint when JWT is provided. [[PR]](https://github.com/prysmaticlabs/prysm/pull/16032)
+- Removed dead slot parameter from blobCacheEntry.filter. [[PR]](https://github.com/prysmaticlabs/prysm/pull/16021)
+- Added log prefix to the `genesis` package. [[PR]](https://github.com/prysmaticlabs/prysm/pull/16075)
+- Added log prefix to the `params` package. [[PR]](https://github.com/prysmaticlabs/prysm/pull/16075)
+- `WithGenesisValidatorsRoot`: Use camelCase for log field param. [[PR]](https://github.com/prysmaticlabs/prysm/pull/16075)
+- Move `Origin checkpoint found in db` from WARN to INFO, since it is the expected behaviour. [[PR]](https://github.com/prysmaticlabs/prysm/pull/16075)
+- backfill metrics that changed name and/or histogram buckets: backfill_batch_time_verify -> backfill_batch_verify_ms, backfill_batch_time_waiting -> backfill_batch_waiting_ms, backfill_batch_time_roundtrip -> backfill_batch_roundtrip_ms, backfill_blocks_bytes_downloaded -> backfill_blocks_downloaded_bytes, backfill_batch_time_verify -> backfill_batch_verify_ms, backfill_batch_blocks_time_download -> backfill_batch_blocks_download_ms, backfill_batch_blobs_time_download -> backfill_batch_blobs_download_ms, backfill_blobs_bytes_downloaded -> backfill_blocks_downloaded_bytes. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15580)
+- Move the "Not enough connected peers" (for a given subnet) from WARN to DEBUG. [[PR]](https://github.com/prysmaticlabs/prysm/pull/16087)
+- `blobsDataFromStoredDataColumns`: Ask the use to use the `--supernode` flag and shorten the error mesage. [[PR]](https://github.com/prysmaticlabs/prysm/pull/16097)
+- Introduced flag `--ignore-unviable-attestations` (replaces and deprecates `--disable-last-epoch-targets`) to drop attestations whose target state is not viable; default remains to process them unless explicitly enabled. [[PR]](https://github.com/prysmaticlabs/prysm/pull/16094)
+
+### Removed
+
+- Remove validator cross-client from end-to-end tests. [[PR]](https://github.com/prysmaticlabs/prysm/pull/16025)
+- `NUMBER_OF_COLUMNS` configuration (not in the specification any more, replaced by a preset). [[PR]](https://github.com/prysmaticlabs/prysm/pull/16073)
+- `MAX_CELLS_IN_EXTENDED_MATRIX` configuration (not in the specification any more). [[PR]](https://github.com/prysmaticlabs/prysm/pull/16073)
+
+### Fixed
+
+- Nil check for block if it doesn't exist in the DB in fetchOriginSidecars. [[PR]](https://github.com/prysmaticlabs/prysm/pull/16006)
+- Fix proposals progress bar count [#16020](https://github.com/OffchainLabs/prysm/pull/16020). [[PR]](https://github.com/prysmaticlabs/prysm/pull/16020)
+- Move `BlockGossipReceived` event to the end of gossip validation. [[PR]](https://github.com/prysmaticlabs/prysm/pull/16031)
+- Fix state diff repetitive anchor slot bug. [[PR]](https://github.com/prysmaticlabs/prysm/pull/16037)
+- Check the JWT secret length is exactly 256 bits (32 bytes) as per Engine API specification. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15939)
+- http_error_count now matches the other cases by listing the endpoint name rather than the actual URL requested. This improves metrics cardinality. [[PR]](https://github.com/prysmaticlabs/prysm/pull/16055)
+- Fix array out of bounds in static analyzer. [[PR]](https://github.com/prysmaticlabs/prysm/pull/16058)
+- fixes E2E tests to be able to start from Electra genesis fork or future forks. [[PR]](https://github.com/prysmaticlabs/prysm/pull/16048)
+- Use head state to validate attestations for old blocks if they are compatible. [[PR]](https://github.com/prysmaticlabs/prysm/pull/16095)
+
+## [v7.0.1](https://github.com/prysmaticlabs/prysm/compare/v7.0.0...v7.0.1) - 2025-12-08
+
+This patch release contains 4 cherry-picked changes to address the mainnet attestation processing issue from 2025-12-04. Operators are encouraged to update to this release as soon as practical. As of this release, the feature flag `--disable-last-epoch-targets` has been deprecated and can be safely removed from your node configuration. 
+
+A post mortem doc with full details is expected to be published later this week.
+
+### Changed
+
+- Move the "Not enough connected peers" (for a given subnet) from WARN to DEBUG. [[PR]](https://github.com/prysmaticlabs/prysm/pull/16087)
+- Use dependent root instead of target when possible. [[PR]](https://github.com/prysmaticlabs/prysm/pull/15996)
+- Introduced flag `--ignore-unviable-attestations` (replaces and deprecates `--disable-last-epoch-targets`) to drop attestations whose target state is not viable; default remains to process them unless explicitly enabled. [[PR]](https://github.com/prysmaticlabs/prysm/pull/16094)
+
+### Fixed
+
+- Use head state to validate attestations for old blocks if they are compatible. [[PR]](https://github.com/prysmaticlabs/prysm/pull/16095)
+
+
 ## [v7.0.0](https://github.com/prysmaticlabs/prysm/compare/v6.1.4...v7.0.0) - 2025-11-10
 
 This is our initial mainnet release for the Ethereum mainnet Fulu fork on December 3rd, 2025. All operators MUST update to v7.0.0 or later release prior to the fulu fork epoch `411392`. See the [Ethereum Foundation blog post](https://blog.ethereum.org/2025/11/06/fusaka-mainnet-announcement) for more information on Fulu.

beacon-chain/blockchain/execution_engine.go

@@ -323,14 +323,17 @@ func (s *Service) getPayloadAttribute(ctx context.Context, st state.BeaconState,
 	var ok bool
 	e := slots.ToEpoch(slot)
 	stateEpoch := slots.ToEpoch(st.Slot())
-	if e == stateEpoch {
+	fuluAndNextEpoch := st.Version() >= version.Fulu && e == stateEpoch+1
+	if e == stateEpoch || fuluAndNextEpoch {
 		val, ok = s.trackedProposer(st, slot)
 		if !ok {
 			return emptyAttri
 		}
 	}
-	st = st.Copy()
 	if slot > st.Slot() {
+		// At this point either we know we are proposing on a future slot or we need to still compute the
+		// right proposer index pre-Fulu, either way we need to copy the state to process it.
+		st = st.Copy()
 		var err error
 		st, err = transition.ProcessSlotsUsingNextSlotCache(ctx, st, headRoot, slot)
 		if err != nil {
@@ -338,7 +341,7 @@ func (s *Service) getPayloadAttribute(ctx context.Context, st state.BeaconState,
 			return emptyAttri
 		}
 	}
-	if e > stateEpoch {
+	if e > stateEpoch && !fuluAndNextEpoch {
 		emptyAttri := payloadattribute.EmptyWithVersion(st.Version())
 		val, ok = s.trackedProposer(st, slot)
 		if !ok {

beacon-chain/blockchain/process_attestation_helpers.go

@@ -22,7 +22,7 @@ import (
 // The caller of this function must have a lock on forkchoice.
 func (s *Service) getRecentPreState(ctx context.Context, c *ethpb.Checkpoint) state.ReadOnlyBeaconState {
 	headEpoch := slots.ToEpoch(s.HeadSlot())
-	if c.Epoch < headEpoch || c.Epoch == 0 {
+	if c.Epoch+1 < headEpoch || c.Epoch == 0 {
 		return nil
 	}
 	// Only use head state if the head state is compatible with the target checkpoint.
@@ -30,11 +30,13 @@ func (s *Service) getRecentPreState(ctx context.Context, c *ethpb.Checkpoint) st
 	if err != nil {
 		return nil
 	}
-	headDependent, err := s.cfg.ForkChoiceStore.DependentRootForEpoch([32]byte(headRoot), c.Epoch-1)
+	// headEpoch - 1 equals c.Epoch if c is from the previous epoch and equals c.Epoch - 1 if c is from the current epoch.
+	// We don't use the smaller c.Epoch - 1 because forkchoice would not have the data to answer that.
+	headDependent, err := s.cfg.ForkChoiceStore.DependentRootForEpoch([32]byte(headRoot), headEpoch-1)
 	if err != nil {
 		return nil
 	}
-	targetDependent, err := s.cfg.ForkChoiceStore.DependentRootForEpoch([32]byte(c.Root), c.Epoch-1)
+	targetDependent, err := s.cfg.ForkChoiceStore.DependentRootForEpoch([32]byte(c.Root), headEpoch-1)
 	if err != nil {
 		return nil
 	}
@@ -43,7 +45,7 @@ func (s *Service) getRecentPreState(ctx context.Context, c *ethpb.Checkpoint) st
 	}
 
 	// If the head state alone is enough, we can return it directly read only.
-	if c.Epoch == headEpoch {
+	if c.Epoch <= headEpoch {
 		st, err := s.HeadStateReadOnly(ctx)
 		if err != nil {
 			return nil

beacon-chain/blockchain/process_attestation_test.go

@@ -170,12 +170,13 @@ func TestService_GetRecentPreState(t *testing.T) {
 	err = s.SetFinalizedCheckpoint(cp0)
 	require.NoError(t, err)
 
-	st, root, err := prepareForkchoiceState(ctx, 31, [32]byte(ckRoot), [32]byte{}, [32]byte{'R'}, cp0, cp0)
+	st, blk, err := prepareForkchoiceState(ctx, 31, [32]byte(ckRoot), [32]byte{}, [32]byte{'R'}, cp0, cp0)
 	require.NoError(t, err)
-	require.NoError(t, service.cfg.ForkChoiceStore.InsertNode(ctx, st, root))
+	require.NoError(t, service.cfg.ForkChoiceStore.InsertNode(ctx, st, blk))
 	service.head = &head{
 		root:  [32]byte(ckRoot),
 		state: s,
+		block: blk,
 		slot:  31,
 	}
 	require.NotNil(t, service.getRecentPreState(ctx, &ethpb.Checkpoint{Epoch: 1, Root: ckRoot}))
@@ -197,12 +198,13 @@ func TestService_GetRecentPreState_Old_Checkpoint(t *testing.T) {
 	err = s.SetFinalizedCheckpoint(cp0)
 	require.NoError(t, err)
 
-	st, root, err := prepareForkchoiceState(ctx, 33, [32]byte(ckRoot), [32]byte{}, [32]byte{'R'}, cp0, cp0)
+	st, blk, err := prepareForkchoiceState(ctx, 33, [32]byte(ckRoot), [32]byte{}, [32]byte{'R'}, cp0, cp0)
 	require.NoError(t, err)
-	require.NoError(t, service.cfg.ForkChoiceStore.InsertNode(ctx, st, root))
+	require.NoError(t, service.cfg.ForkChoiceStore.InsertNode(ctx, st, blk))
 	service.head = &head{
 		root:  [32]byte(ckRoot),
 		state: s,
+		block: blk,
 		slot:  33,
 	}
 	require.IsNil(t, service.getRecentPreState(ctx, &ethpb.Checkpoint{}))
@@ -227,6 +229,7 @@ func TestService_GetRecentPreState_Same_DependentRoots(t *testing.T) {
 	require.NoError(t, service.cfg.ForkChoiceStore.InsertNode(ctx, st, blk))
 	st, blk, err = prepareForkchoiceState(ctx, 64, [32]byte{'T'}, blk.Root(), [32]byte{}, cp0, cp0)
 	require.NoError(t, err)
+	headBlock := blk
 	require.NoError(t, service.cfg.ForkChoiceStore.InsertNode(ctx, st, blk))
 	st, blk, err = prepareForkchoiceState(ctx, 33, [32]byte{'U'}, [32]byte(ckRoot), [32]byte{}, cp0, cp0)
 	require.NoError(t, err)
@@ -235,8 +238,9 @@ func TestService_GetRecentPreState_Same_DependentRoots(t *testing.T) {
 
 	service.head = &head{
 		root:  [32]byte{'T'},
-		state: s,
+		block: headBlock,
 		slot:  64,
+		state: s,
 	}
 	require.NotNil(t, service.getRecentPreState(ctx, &ethpb.Checkpoint{Epoch: 2, Root: cpRoot[:]}))
 }
@@ -263,6 +267,7 @@ func TestService_GetRecentPreState_Different_DependentRoots(t *testing.T) {
 	require.NoError(t, service.cfg.ForkChoiceStore.InsertNode(ctx, st, blk))
 	st, blk, err = prepareForkchoiceState(ctx, 64, [32]byte{'U'}, blk.Root(), [32]byte{}, cp0, cp0)
 	require.NoError(t, err)
+	headBlock := blk
 	require.NoError(t, service.cfg.ForkChoiceStore.InsertNode(ctx, st, blk))
 	st, blk, err = prepareForkchoiceState(ctx, 33, [32]byte{'V'}, [32]byte(ckRoot), [32]byte{}, cp0, cp0)
 	require.NoError(t, err)
@@ -270,7 +275,8 @@ func TestService_GetRecentPreState_Different_DependentRoots(t *testing.T) {
 	cpRoot := blk.Root()
 
 	service.head = &head{
-		root:  [32]byte{'T'},
+		root:  [32]byte{'U'},
+		block: headBlock,
 		state: s,
 		slot:  64,
 	}
@@ -287,12 +293,13 @@ func TestService_GetRecentPreState_Different(t *testing.T) {
 	err = s.SetFinalizedCheckpoint(cp0)
 	require.NoError(t, err)
 
-	st, root, err := prepareForkchoiceState(ctx, 33, [32]byte(ckRoot), [32]byte{}, [32]byte{'R'}, cp0, cp0)
+	st, blk, err := prepareForkchoiceState(ctx, 33, [32]byte(ckRoot), [32]byte{}, [32]byte{'R'}, cp0, cp0)
 	require.NoError(t, err)
-	require.NoError(t, service.cfg.ForkChoiceStore.InsertNode(ctx, st, root))
+	require.NoError(t, service.cfg.ForkChoiceStore.InsertNode(ctx, st, blk))
 	service.head = &head{
 		root:  [32]byte(ckRoot),
 		state: s,
+		block: blk,
 		slot:  33,
 	}
 	require.IsNil(t, service.getRecentPreState(ctx, &ethpb.Checkpoint{}))

beacon-chain/blockchain/process_block.go

@@ -295,14 +295,6 @@ func (s *Service) onBlockBatch(ctx context.Context, blks []consensusblocks.ROBlo
 			return errors.Wrap(err, "could not set optimistic block to valid")
 		}
 	}
-	arg := &fcuConfig{
-		headState: preState,
-		headRoot:  lastBR,
-		headBlock: lastB,
-	}
-	if _, err := s.notifyForkchoiceUpdate(ctx, arg); err != nil {
-		return err
-	}
 	return s.saveHeadNoDB(ctx, lastB, lastBR, preState, !isValidPayload)
 }
 

beacon-chain/blockchain/process_block_test.go

@@ -820,24 +820,6 @@ func TestOnBlock_NilBlock(t *testing.T) {
 	require.Equal(t, true, IsInvalidBlock(err))
 }
 
-func TestOnBlock_InvalidSignature(t *testing.T) {
-	service, tr := minimalTestService(t)
-	ctx := tr.ctx
-
-	gs, keys := util.DeterministicGenesisState(t, 32)
-	require.NoError(t, service.saveGenesisData(ctx, gs))
-
-	blk, err := util.GenerateFullBlock(gs, keys, util.DefaultBlockGenConfig(), 1)
-	require.NoError(t, err)
-	blk.Signature = []byte{'a'} // Mutate the signature.
-	wsb, err := consensusblocks.NewSignedBeaconBlock(blk)
-	require.NoError(t, err)
-	preState, err := service.getBlockPreState(ctx, wsb.Block())
-	require.NoError(t, err)
-	_, err = service.validateStateTransition(ctx, preState, wsb)
-	require.Equal(t, true, IsInvalidBlock(err))
-}
-
 func TestOnBlock_CallNewPayloadAndForkchoiceUpdated(t *testing.T) {
 	params.SetupTestConfigCleanup(t)
 	config := params.BeaconConfig()

beacon-chain/core/blocks/eth1_data.go

@@ -60,7 +60,7 @@ func Eth1DataHasEnoughSupport(beaconState state.ReadOnlyBeaconState, data *ethpb
 	voteCount := uint64(0)
 
 	for _, vote := range beaconState.Eth1DataVotes() {
-		if AreEth1DataEqual(vote, data.Copy()) {
+		if AreEth1DataEqual(vote, data) {
 			voteCount++
 		}
 	}

beacon-chain/core/blocks/header_test.go

@@ -290,52 +290,3 @@ func TestProcessBlockHeader_OK(t *testing.T) {
 	}
 	assert.Equal(t, true, proto.Equal(nsh, expected), "Expected %v, received %v", expected, nsh)
 }
-
-func TestBlockSignatureSet_OK(t *testing.T) {
-	validators := make([]*ethpb.Validator, params.BeaconConfig().MinGenesisActiveValidatorCount)
-	for i := range validators {
-		validators[i] = &ethpb.Validator{
-			PublicKey:             make([]byte, 32),
-			WithdrawalCredentials: make([]byte, 32),
-			ExitEpoch:             params.BeaconConfig().FarFutureEpoch,
-			Slashed:               true,
-		}
-	}
-
-	state, err := util.NewBeaconState()
-	require.NoError(t, err)
-	require.NoError(t, state.SetValidators(validators))
-	require.NoError(t, state.SetSlot(10))
-	require.NoError(t, state.SetLatestBlockHeader(util.HydrateBeaconHeader(&ethpb.BeaconBlockHeader{
-		Slot:          9,
-		ProposerIndex: 0,
-	})))
-
-	latestBlockSignedRoot, err := state.LatestBlockHeader().HashTreeRoot()
-	require.NoError(t, err)
-
-	currentEpoch := time.CurrentEpoch(state)
-	priv, err := bls.RandKey()
-	require.NoError(t, err)
-	pID, err := helpers.BeaconProposerIndex(t.Context(), state)
-	require.NoError(t, err)
-	block := util.NewBeaconBlock()
-	block.Block.Slot = 10
-	block.Block.ProposerIndex = pID
-	block.Block.Body.RandaoReveal = bytesutil.PadTo([]byte{'A', 'B', 'C'}, 96)
-	block.Block.ParentRoot = latestBlockSignedRoot[:]
-	block.Signature, err = signing.ComputeDomainAndSign(state, currentEpoch, block.Block, params.BeaconConfig().DomainBeaconProposer, priv)
-	require.NoError(t, err)
-	proposerIdx, err := helpers.BeaconProposerIndex(t.Context(), state)
-	require.NoError(t, err)
-	validators[proposerIdx].Slashed = false
-	validators[proposerIdx].PublicKey = priv.PublicKey().Marshal()
-	err = state.UpdateValidatorAtIndex(proposerIdx, validators[proposerIdx])
-	require.NoError(t, err)
-	set, err := blocks.BlockSignatureBatch(state, block.Block.ProposerIndex, block.Signature, block.Block.HashTreeRoot)
-	require.NoError(t, err)
-
-	verified, err := set.Verify()
-	require.NoError(t, err)
-	assert.Equal(t, true, verified, "Block signature set returned a set which was unable to be verified")
-}

beacon-chain/core/blocks/signature.go

@@ -122,24 +122,6 @@ func VerifyBlockSignatureUsingCurrentFork(beaconState state.ReadOnlyBeaconState,
 	return nil
 }
 
-// BlockSignatureBatch retrieves the block signature batch from the provided block and its corresponding state.
-func BlockSignatureBatch(beaconState state.ReadOnlyBeaconState,
-	proposerIndex primitives.ValidatorIndex,
-	sig []byte,
-	rootFunc func() ([32]byte, error)) (*bls.SignatureBatch, error) {
-	currentEpoch := slots.ToEpoch(beaconState.Slot())
-	domain, err := signing.Domain(beaconState.Fork(), currentEpoch, params.BeaconConfig().DomainBeaconProposer, beaconState.GenesisValidatorsRoot())
-	if err != nil {
-		return nil, err
-	}
-	proposer, err := beaconState.ValidatorAtIndex(proposerIndex)
-	if err != nil {
-		return nil, err
-	}
-	proposerPubKey := proposer.PublicKey
-	return signing.BlockSignatureBatch(proposerPubKey, sig, domain, rootFunc)
-}
-
 // RandaoSignatureBatch retrieves the relevant randao specific signature batch object
 // from a block and its corresponding state.
 func RandaoSignatureBatch(

beacon-chain/core/electra/consolidations.go

@@ -278,12 +278,12 @@ func ProcessConsolidationRequests(ctx context.Context, st state.BeaconState, req
 		if uint64(curEpoch) < e {
 			continue
 		}
-		bal, err := st.PendingBalanceToWithdraw(srcIdx)
+		hasBal, err := st.HasPendingBalanceToWithdraw(srcIdx)
 		if err != nil {
 			log.WithError(err).Error("Failed to fetch pending balance to withdraw")
 			continue
 		}
-		if bal > 0 {
+		if hasBal {
 			continue
 		}
 

beacon-chain/core/helpers/validators.go

@@ -152,7 +152,7 @@ func ActiveValidatorIndices(ctx context.Context, s state.ReadOnlyBeaconState, ep
 	}
 
 	if err := UpdateCommitteeCache(ctx, s, epoch); err != nil {
-		return nil, errors.Wrap(err, "could not update committee cache")
+		log.WithError(err).Error("Could not update committee cache")
 	}
 
 	return indices, nil

beacon-chain/core/peerdas/metrics.go

@@ -5,10 +5,20 @@ import (
 	"github.com/prometheus/client_golang/prometheus/promauto"
 )
 
-var dataColumnComputationTime = promauto.NewHistogram(
-	prometheus.HistogramOpts{
-		Name:    "beacon_data_column_sidecar_computation_milliseconds",
-		Help:    "Captures the time taken to compute data column sidecars from blobs.",
-		Buckets: []float64{25, 50, 100, 250, 500, 750, 1000},
-	},
+var (
+	dataColumnComputationTime = promauto.NewHistogram(
+		prometheus.HistogramOpts{
+			Name:    "beacon_data_column_sidecar_computation_milliseconds",
+			Help:    "Captures the time taken to compute data column sidecars from blobs.",
+			Buckets: []float64{25, 50, 100, 250, 500, 750, 1000},
+		},
+	)
+
+	cellsAndProofsFromStructuredComputationTime = promauto.NewHistogram(
+		prometheus.HistogramOpts{
+			Name:    "cells_and_proofs_from_structured_computation_milliseconds",
+			Help:    "Captures the time taken to compute cells and proofs from structured computation.",
+			Buckets: []float64{10, 20, 30, 40, 50, 100, 200},
+		},
+	)
 )

beacon-chain/core/peerdas/reconstruction.go

@@ -3,6 +3,7 @@ package peerdas
 import (
 	"sort"
 	"sync"
+	"time"
 
 	"github.com/OffchainLabs/prysm/v7/beacon-chain/blockchain/kzg"
 	fieldparams "github.com/OffchainLabs/prysm/v7/config/fieldparams"
@@ -296,32 +297,42 @@ func ComputeCellsAndProofsFromFlat(blobs [][]byte, cellProofs [][]byte) ([][]kzg
 		return nil, nil, ErrBlobsCellsProofsMismatch
 	}
 
-	cellsPerBlob := make([][]kzg.Cell, 0, blobCount)
-	proofsPerBlob := make([][]kzg.Proof, 0, blobCount)
+	var wg errgroup.Group
+
+	cellsPerBlob := make([][]kzg.Cell, blobCount)
+	proofsPerBlob := make([][]kzg.Proof, blobCount)
+
 	for i, blob := range blobs {
-		var kzgBlob kzg.Blob
-		if copy(kzgBlob[:], blob) != len(kzgBlob) {
-			return nil, nil, errors.New("wrong blob size - should never happen")
-		}
-
-		// Compute the extended cells from the (non-extended) blob.
-		cells, err := kzg.ComputeCells(&kzgBlob)
-		if err != nil {
-			return nil, nil, errors.Wrap(err, "compute cells")
-		}
-
-		var proofs []kzg.Proof
-		for idx := uint64(i) * numberOfColumns; idx < (uint64(i)+1)*numberOfColumns; idx++ {
-			var kzgProof kzg.Proof
-			if copy(kzgProof[:], cellProofs[idx]) != len(kzgProof) {
-				return nil, nil, errors.New("wrong KZG proof size - should never happen")
+		wg.Go(func() error {
+			var kzgBlob kzg.Blob
+			if copy(kzgBlob[:], blob) != len(kzgBlob) {
+				return errors.New("wrong blob size - should never happen")
 			}
 
-			proofs = append(proofs, kzgProof)
-		}
+			// Compute the extended cells from the (non-extended) blob.
+			cells, err := kzg.ComputeCells(&kzgBlob)
+			if err != nil {
+				return errors.Wrap(err, "compute cells")
+			}
 
-		cellsPerBlob = append(cellsPerBlob, cells)
-		proofsPerBlob = append(proofsPerBlob, proofs)
+			proofs := make([]kzg.Proof, 0, numberOfColumns)
+			for idx := uint64(i) * numberOfColumns; idx < (uint64(i)+1)*numberOfColumns; idx++ {
+				var kzgProof kzg.Proof
+				if copy(kzgProof[:], cellProofs[idx]) != len(kzgProof) {
+					return errors.New("wrong KZG proof size - should never happen")
+				}
+
+				proofs = append(proofs, kzgProof)
+			}
+
+			cellsPerBlob[i] = cells
+			proofsPerBlob[i] = proofs
+			return nil
+		})
+	}
+
+	if err := wg.Wait(); err != nil {
+		return nil, nil, err
 	}
 
 	return cellsPerBlob, proofsPerBlob, nil
@@ -329,40 +340,55 @@ func ComputeCellsAndProofsFromFlat(blobs [][]byte, cellProofs [][]byte) ([][]kzg
 
 // ComputeCellsAndProofsFromStructured computes the cells and proofs from blobs and cell proofs.
 func ComputeCellsAndProofsFromStructured(blobsAndProofs []*pb.BlobAndProofV2) ([][]kzg.Cell, [][]kzg.Proof, error) {
-	cellsPerBlob := make([][]kzg.Cell, 0, len(blobsAndProofs))
-	proofsPerBlob := make([][]kzg.Proof, 0, len(blobsAndProofs))
-	for _, blobAndProof := range blobsAndProofs {
+	start := time.Now()
+	defer func() {
+		cellsAndProofsFromStructuredComputationTime.Observe(float64(time.Since(start).Milliseconds()))
+	}()
+
+	var wg errgroup.Group
+
+	cellsPerBlob := make([][]kzg.Cell, len(blobsAndProofs))
+	proofsPerBlob := make([][]kzg.Proof, len(blobsAndProofs))
+
+	for i, blobAndProof := range blobsAndProofs {
 		if blobAndProof == nil {
 			return nil, nil, ErrNilBlobAndProof
 		}
 
-		var kzgBlob kzg.Blob
-		if copy(kzgBlob[:], blobAndProof.Blob) != len(kzgBlob) {
-			return nil, nil, errors.New("wrong blob size - should never happen")
-		}
-
-		// Compute the extended cells from the (non-extended) blob.
-		cells, err := kzg.ComputeCells(&kzgBlob)
-		if err != nil {
-			return nil, nil, errors.Wrap(err, "compute cells")
-		}
-
-		kzgProofs := make([]kzg.Proof, 0, fieldparams.NumberOfColumns)
-		for _, kzgProofBytes := range blobAndProof.KzgProofs {
-			if len(kzgProofBytes) != kzg.BytesPerProof {
-				return nil, nil, errors.New("wrong KZG proof size - should never happen")
+		wg.Go(func() error {
+			var kzgBlob kzg.Blob
+			if copy(kzgBlob[:], blobAndProof.Blob) != len(kzgBlob) {
+				return errors.New("wrong blob size - should never happen")
 			}
 
-			var kzgProof kzg.Proof
-			if copy(kzgProof[:], kzgProofBytes) != len(kzgProof) {
-				return nil, nil, errors.New("wrong copied KZG proof size - should never happen")
+			// Compute the extended cells from the (non-extended) blob.
+			cells, err := kzg.ComputeCells(&kzgBlob)
+			if err != nil {
+				return errors.Wrap(err, "compute cells")
 			}
 
-			kzgProofs = append(kzgProofs, kzgProof)
-		}
+			kzgProofs := make([]kzg.Proof, 0, fieldparams.NumberOfColumns)
+			for _, kzgProofBytes := range blobAndProof.KzgProofs {
+				if len(kzgProofBytes) != kzg.BytesPerProof {
+					return errors.New("wrong KZG proof size - should never happen")
+				}
 
-		cellsPerBlob = append(cellsPerBlob, cells)
-		proofsPerBlob = append(proofsPerBlob, kzgProofs)
+				var kzgProof kzg.Proof
+				if copy(kzgProof[:], kzgProofBytes) != len(kzgProof) {
+					return errors.New("wrong copied KZG proof size - should never happen")
+				}
+
+				kzgProofs = append(kzgProofs, kzgProof)
+			}
+
+			cellsPerBlob[i] = cells
+			proofsPerBlob[i] = kzgProofs
+			return nil
+		})
+	}
+
+	if err := wg.Wait(); err != nil {
+		return nil, nil, err
 	}
 
 	return cellsPerBlob, proofsPerBlob, nil

beacon-chain/core/transition/transition_no_verify_sig.go

@@ -182,12 +182,6 @@ func ProcessBlockNoVerifyAnySig(
 		return nil, nil, err
 	}
 
-	sig := signed.Signature()
-	bSet, err := b.BlockSignatureBatch(st, blk.ProposerIndex(), sig[:], blk.HashTreeRoot)
-	if err != nil {
-		tracing.AnnotateError(span, err)
-		return nil, nil, errors.Wrap(err, "could not retrieve block signature set")
-	}
 	randaoReveal := signed.Block().Body().RandaoReveal()
 	rSet, err := b.RandaoSignatureBatch(ctx, st, randaoReveal[:])
 	if err != nil {
@@ -201,7 +195,7 @@ func ProcessBlockNoVerifyAnySig(
 
 	// Merge beacon block, randao and attestations signatures into a set.
 	set := bls.NewSet()
-	set.Join(bSet).Join(rSet).Join(aSet)
+	set.Join(rSet).Join(aSet)
 
 	if blk.Version() >= version.Capella {
 		changes, err := signed.Block().Body().BLSToExecutionChanges()

beacon-chain/core/transition/transition_no_verify_sig_test.go

@@ -157,9 +157,8 @@ func TestProcessBlockNoVerify_SigSetContainsDescriptions(t *testing.T) {
 	set, _, err := transition.ProcessBlockNoVerifyAnySig(t.Context(), beaconState, wsb)
 	require.NoError(t, err)
 	assert.Equal(t, len(set.Signatures), len(set.Descriptions), "Signatures and descriptions do not match up")
-	assert.Equal(t, "block signature", set.Descriptions[0])
-	assert.Equal(t, "randao signature", set.Descriptions[1])
-	assert.Equal(t, "attestation signature", set.Descriptions[2])
+	assert.Equal(t, "randao signature", set.Descriptions[0])
+	assert.Equal(t, "attestation signature", set.Descriptions[1])
 }
 
 func TestProcessOperationsNoVerifyAttsSigs_OK(t *testing.T) {

beacon-chain/das/needs.go

@@ -67,9 +67,9 @@ func NewSyncNeeds(current CurrentSlotter, oldestSlotFlagPtr *primitives.Slot, bl
 
 	// Override spec minimum block retention with user-provided flag only if it is lower than the spec minimum.
 	sn.blockRetention = primitives.Epoch(params.BeaconConfig().MinEpochsForBlockRequests)
+
 	if oldestSlotFlagPtr != nil {
-		oldestEpoch := slots.ToEpoch(*oldestSlotFlagPtr)
-		if oldestEpoch < sn.blockRetention {
+		if *oldestSlotFlagPtr <= syncEpochOffset(current(), sn.blockRetention) {
 			sn.validOldestSlotPtr = oldestSlotFlagPtr
 		} else {
 			log.WithField("backfill-oldest-slot", *oldestSlotFlagPtr).

beacon-chain/das/needs_test.go

@@ -128,6 +128,9 @@ func TestSyncNeedsInitialize(t *testing.T) {
 	slotsPerEpoch := params.BeaconConfig().SlotsPerEpoch
 	minBlobEpochs := params.BeaconConfig().MinEpochsForBlobsSidecarsRequest
 	minColEpochs := params.BeaconConfig().MinEpochsForDataColumnSidecarsRequest
+	denebSlot := slots.UnsafeEpochStart(params.BeaconConfig().DenebForkEpoch)
+	fuluSlot := slots.UnsafeEpochStart(params.BeaconConfig().FuluForkEpoch)
+	minSlots := slots.UnsafeEpochStart(primitives.Epoch(params.BeaconConfig().MinEpochsForBlockRequests))
 
 	currentSlot := primitives.Slot(10000)
 	currentFunc := func() primitives.Slot { return currentSlot }
@@ -141,6 +144,7 @@ func TestSyncNeedsInitialize(t *testing.T) {
 		expectedCol       primitives.Epoch
 		name              string
 		input             SyncNeeds
+		current           func() primitives.Slot
 	}{
 		{
 			name:              "basic initialization with no flags",
@@ -174,13 +178,13 @@ func TestSyncNeedsInitialize(t *testing.T) {
 		{
 			name:              "valid oldestSlotFlagPtr (earlier than spec minimum)",
 			blobRetentionFlag: 0,
-			oldestSlotFlagPtr: func() *primitives.Slot {
-				slot := primitives.Slot(10)
-				return &slot
-			}(),
+			oldestSlotFlagPtr: &denebSlot,
 			expectValidOldest: true,
 			expectedBlob:      minBlobEpochs,
 			expectedCol:       minColEpochs,
+			current: func() primitives.Slot {
+				return fuluSlot + minSlots
+			},
 		},
 		{
 			name:              "invalid oldestSlotFlagPtr (later than spec minimum)",
@@ -210,6 +214,9 @@ func TestSyncNeedsInitialize(t *testing.T) {
 		{
 			name:              "both blob retention flag and oldest slot set",
 			blobRetentionFlag: minBlobEpochs + 5,
+			current: func() primitives.Slot {
+				return fuluSlot + minSlots
+			},
 			oldestSlotFlagPtr: func() *primitives.Slot {
 				slot := primitives.Slot(100)
 				return &slot
@@ -232,16 +239,27 @@ func TestSyncNeedsInitialize(t *testing.T) {
 			expectedBlob:      5000,
 			expectedCol:       5000,
 		},
+		{
+			name:              "regression for deneb start",
+			blobRetentionFlag: 8212500,
+			expectValidOldest: true,
+			oldestSlotFlagPtr: &denebSlot,
+			current: func() primitives.Slot {
+				return fuluSlot + minSlots
+			},
+			expectedBlob: 8212500,
+			expectedCol:  8212500,
+		},
 	}
 
 	for _, tc := range cases {
 		t.Run(tc.name, func(t *testing.T) {
-			result, err := NewSyncNeeds(currentFunc, tc.oldestSlotFlagPtr, tc.blobRetentionFlag)
+			if tc.current == nil {
+				tc.current = currentFunc
+			}
+			result, err := NewSyncNeeds(tc.current, tc.oldestSlotFlagPtr, tc.blobRetentionFlag)
 			require.NoError(t, err)
 
-			// Check that current, deneb, fulu are set correctly
-			require.Equal(t, currentSlot, result.current())
-
 			// Check retention calculations
 			require.Equal(t, tc.expectedBlob, result.blobRetention)
 			require.Equal(t, tc.expectedCol, result.colRetention)

beacon-chain/db/filesystem/data_column.go

@@ -515,6 +515,11 @@ func (dcs *DataColumnStorage) Clear() error {
 
 // prune clean the cache, the filesystem and mutexes.
 func (dcs *DataColumnStorage) prune() {
+	startTime := time.Now()
+	defer func() {
+		dataColumnPruneLatency.Observe(float64(time.Since(startTime).Milliseconds()))
+	}()
+
 	highestStoredEpoch := dcs.cache.HighestEpoch()
 
 	// Check if we need to prune.
@@ -622,6 +627,9 @@ func (dcs *DataColumnStorage) saveDataColumnSidecarsExistingFile(filePath string
 	// Create the SSZ encoded data column sidecars.
 	var sszEncodedDataColumnSidecars []byte
 
+	// Initialize the count of the saved SSZ encoded data column sidecar.
+	storedCount := uint8(0)
+
 	for {
 		dataColumnSidecars := pullChan(inputDataColumnSidecars)
 		if len(dataColumnSidecars) == 0 {
@@ -668,6 +676,9 @@ func (dcs *DataColumnStorage) saveDataColumnSidecarsExistingFile(filePath string
 				return errors.Wrap(err, "set index")
 			}
 
+			// Increment the count of the saved SSZ encoded data column sidecar.
+			storedCount++
+
 			// Append the SSZ encoded data column sidecar to the SSZ encoded data column sidecars.
 			sszEncodedDataColumnSidecars = append(sszEncodedDataColumnSidecars, sszEncodedDataColumnSidecar...)
 		}
@@ -692,9 +703,12 @@ func (dcs *DataColumnStorage) saveDataColumnSidecarsExistingFile(filePath string
 		return errWrongBytesWritten
 	}
 
+	syncStart := time.Now()
 	if err := file.Sync(); err != nil {
 		return errors.Wrap(err, "sync")
 	}
+	dataColumnFileSyncLatency.Observe(float64(time.Since(syncStart).Milliseconds()))
+	dataColumnBatchStoreCount.Observe(float64(storedCount))
 
 	return nil
 }
@@ -808,10 +822,14 @@ func (dcs *DataColumnStorage) saveDataColumnSidecarsNewFile(filePath string, inp
 		return errWrongBytesWritten
 	}
 
+	syncStart := time.Now()
 	if err := file.Sync(); err != nil {
 		return errors.Wrap(err, "sync")
 	}
 
+	dataColumnFileSyncLatency.Observe(float64(time.Since(syncStart).Milliseconds()))
+	dataColumnBatchStoreCount.Observe(float64(storedCount))
+
 	return nil
 }
 

beacon-chain/db/filesystem/metrics.go

@@ -36,16 +36,15 @@ var (
 	})
 
 	// Data columns
-	dataColumnBuckets     = []float64{3, 5, 7, 9, 11, 13}
 	dataColumnSaveLatency = promauto.NewHistogram(prometheus.HistogramOpts{
 		Name:    "data_column_storage_save_latency",
 		Help:    "Latency of DataColumnSidecar storage save operations in milliseconds",
-		Buckets: dataColumnBuckets,
+		Buckets: []float64{10, 20, 30, 50, 100, 200, 500},
 	})
 	dataColumnFetchLatency = promauto.NewHistogram(prometheus.HistogramOpts{
 		Name:    "data_column_storage_get_latency",
 		Help:    "Latency of DataColumnSidecar storage get operations in milliseconds",
-		Buckets: dataColumnBuckets,
+		Buckets: []float64{3, 5, 7, 9, 11, 13},
 	})
 	dataColumnPrunedCounter = promauto.NewCounter(prometheus.CounterOpts{
 		Name: "data_column_pruned",
@@ -59,4 +58,16 @@ var (
 		Name: "data_column_disk_count",
 		Help: "Approximate number of data columns in storage",
 	})
+	dataColumnFileSyncLatency = promauto.NewSummary(prometheus.SummaryOpts{
+		Name: "data_column_file_sync_latency",
+		Help: "Latency of sync operations when saving data columns in milliseconds",
+	})
+	dataColumnBatchStoreCount = promauto.NewSummary(prometheus.SummaryOpts{
+		Name: "data_column_batch_store_count",
+		Help: "Number of data columns stored in a batch",
+	})
+	dataColumnPruneLatency = promauto.NewSummary(prometheus.SummaryOpts{
+		Name: "data_column_prune_latency",
+		Help: "Latency of data column prune operations in milliseconds",
+	})
 )

beacon-chain/db/iface/interface.go

@@ -89,6 +89,7 @@ type NoHeadAccessDatabase interface {
 	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
+	SlotByBlockRoot(context.Context, [32]byte) (primitives.Slot, error)
 	// State related methods.
 	SaveState(ctx context.Context, state state.ReadOnlyBeaconState, blockRoot [32]byte) error
 	SaveStates(ctx context.Context, states []state.ReadOnlyBeaconState, blockRoots [][32]byte) error
@@ -96,6 +97,7 @@ type NoHeadAccessDatabase interface {
 	DeleteStates(ctx context.Context, blockRoots [][32]byte) error
 	SaveStateSummary(ctx context.Context, summary *ethpb.StateSummary) error
 	SaveStateSummaries(ctx context.Context, summaries []*ethpb.StateSummary) error
+	SlotInDiffTree(primitives.Slot) (uint64, int, error)
 	// Checkpoint operations.
 	SaveJustifiedCheckpoint(ctx context.Context, checkpoint *ethpb.Checkpoint) error
 	SaveFinalizedCheckpoint(ctx context.Context, checkpoint *ethpb.Checkpoint) error

beacon-chain/db/kv/BUILD.bazel

@@ -32,6 +32,7 @@ go_library(
         "state_diff_helpers.go",
         "state_summary.go",
         "state_summary_cache.go",
+        "testing_helpers.go",
         "utils.go",
         "validated_checkpoint.go",
         "wss.go",

beacon-chain/db/kv/state_diff.go

@@ -23,6 +23,16 @@ const (
 	The data at level 0 is saved every 2**exponent[0] slots and always contains a full state snapshot that is used as a base for the delta saved at other levels.
 */
 
+// SlotInDiffTree returns whether the given slot is a saving point in the diff tree.
+// It it is, it also returns the offset and level in the tree.
+func (s *Store) SlotInDiffTree(slot primitives.Slot) (uint64, int, error) {
+	offset := s.getOffset()
+	if uint64(slot) < offset {
+		return 0, -1, ErrSlotBeforeOffset
+	}
+	return offset, computeLevel(offset, slot), nil
+}
+
 // saveStateByDiff takes a state and decides between saving a full state snapshot or a diff.
 func (s *Store) saveStateByDiff(ctx context.Context, st state.ReadOnlyBeaconState) error {
 	_, span := trace.StartSpan(ctx, "BeaconDB.saveStateByDiff")
@@ -33,13 +43,10 @@ func (s *Store) saveStateByDiff(ctx context.Context, st state.ReadOnlyBeaconStat
 	}
 
 	slot := st.Slot()
-	offset := s.getOffset()
-	if uint64(slot) < offset {
-		return ErrSlotBeforeOffset
+	offset, lvl, err := s.SlotInDiffTree(slot)
+	if err != nil {
+		return errors.Wrap(err, "could not determine if slot is in diff tree")
 	}
-
-	// Find the level to save the state.
-	lvl := computeLevel(offset, slot)
 	if lvl == -1 {
 		return nil
 	}

beacon-chain/db/kv/testing_helpers.go

@@ -0,0 +1,37 @@
+package kv
+
+import (
+	"encoding/binary"
+	"testing"
+
+	"go.etcd.io/bbolt"
+)
+
+// InitStateDiffCacheForTesting initializes the state diff cache with the given offset.
+// This is intended for testing purposes when setting up state diff after database creation.
+// This file is only compiled when the "testing" build tag is set.
+func (s *Store) InitStateDiffCacheForTesting(t testing.TB, offset uint64) error {
+	// First, set the offset in the database.
+	err := s.db.Update(func(tx *bbolt.Tx) error {
+		bucket := tx.Bucket(stateDiffBucket)
+		if bucket == nil {
+			return bbolt.ErrBucketNotFound
+		}
+
+		offsetBytes := make([]byte, 8)
+		binary.LittleEndian.PutUint64(offsetBytes, offset)
+		return bucket.Put([]byte("offset"), offsetBytes)
+	})
+
+	if err != nil {
+		return err
+	}
+
+	// Then create the state diff cache.
+	sdCache, err := newStateDiffCache(s)
+	if err != nil {
+		return err
+	}
+	s.stateDiffCache = sdCache
+	return nil
+}

beacon-chain/execution/engine_client.go

@@ -532,12 +532,19 @@ func (s *Service) GetBlobsV2(ctx context.Context, versionedHashes []common.Hash)
 	ctx, span := trace.StartSpan(ctx, "powchain.engine-api-client.GetBlobsV2")
 	defer span.End()
 
+	start := time.Now()
+
 	if !s.capabilityCache.has(GetBlobsV2) {
 		return nil, errors.New(fmt.Sprintf("%s is not supported", GetBlobsV2))
 	}
 
 	result := make([]*pb.BlobAndProofV2, len(versionedHashes))
 	err := s.rpcClient.CallContext(ctx, &result, GetBlobsV2, versionedHashes)
+
+	if len(result) != 0 {
+		getBlobsV2Latency.Observe(float64(time.Since(start).Milliseconds()))
+	}
+
 	return result, handleRPCError(err)
 }
 

beacon-chain/execution/metrics.go

@@ -27,6 +27,13 @@ var (
 			Buckets: []float64{25, 50, 100, 200, 500, 1000, 2000, 4000},
 		},
 	)
+	getBlobsV2Latency = promauto.NewHistogram(
+		prometheus.HistogramOpts{
+			Name:    "get_blobs_v2_latency_milliseconds",
+			Help:    "Captures RPC latency for getBlobsV2 in milliseconds",
+			Buckets: []float64{25, 50, 100, 200, 500, 1000, 2000, 4000},
+		},
+	)
 	errParseCount = promauto.NewCounter(prometheus.CounterOpts{
 		Name: "execution_parse_error_count",
 		Help: "The number of errors that occurred while parsing execution payload",

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

@@ -642,8 +642,12 @@ func (f *ForkChoice) DependentRootForEpoch(root [32]byte, epoch primitives.Epoch
 	if !ok || node == nil {
 		return [32]byte{}, ErrNilNode
 	}
-	if slots.ToEpoch(node.slot) >= epoch && node.parent != nil {
-		node = node.parent
+	if slots.ToEpoch(node.slot) >= epoch {
+		if node.parent != nil {
+			node = node.parent
+		} else {
+			return f.store.finalizedDependentRoot, nil
+		}
 	}
 	return node.root, nil
 }

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

@@ -212,6 +212,9 @@ func (s *Store) prune(ctx context.Context) error {
 		return nil
 	}
 
+	// Save the new finalized dependent root because it will be pruned
+	s.finalizedDependentRoot = finalizedNode.parent.root
+
 	// Prune nodeByRoot starting from root
 	if err := s.pruneFinalizedNodeByRootMap(ctx, s.treeRootNode, finalizedNode); err != nil {
 		return err

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

@@ -465,6 +465,7 @@ func TestStore_TargetRootForEpoch(t *testing.T) {
 	ctx := t.Context()
 	f := setup(1, 1)
 
+	// Insert a block in slot 32
 	state, blk, err := prepareForkchoiceState(ctx, params.BeaconConfig().SlotsPerEpoch, [32]byte{'a'}, params.BeaconConfig().ZeroHash, params.BeaconConfig().ZeroHash, 1, 1)
 	require.NoError(t, err)
 	require.NoError(t, f.InsertNode(ctx, state, blk))
@@ -475,6 +476,7 @@ func TestStore_TargetRootForEpoch(t *testing.T) {
 	require.NoError(t, err)
 	require.Equal(t, dependent, [32]byte{})
 
+	// Insert a block in slot 33
 	state, blk1, err := prepareForkchoiceState(ctx, params.BeaconConfig().SlotsPerEpoch+1, [32]byte{'b'}, blk.Root(), params.BeaconConfig().ZeroHash, 1, 1)
 	require.NoError(t, err)
 	require.NoError(t, f.InsertNode(ctx, state, blk1))
@@ -488,7 +490,7 @@ func TestStore_TargetRootForEpoch(t *testing.T) {
 	require.NoError(t, err)
 	require.Equal(t, dependent, [32]byte{})
 
-	// Insert a block for the next epoch (missed slot 0)
+	// Insert a block for the next epoch (missed slot 0), slot 65
 
 	state, blk2, err := prepareForkchoiceState(ctx, 2*params.BeaconConfig().SlotsPerEpoch+1, [32]byte{'c'}, blk1.Root(), params.BeaconConfig().ZeroHash, 1, 1)
 	require.NoError(t, err)
@@ -509,6 +511,7 @@ func TestStore_TargetRootForEpoch(t *testing.T) {
 	require.NoError(t, err)
 	require.Equal(t, dependent, blk1.Root())
 
+	// Insert a block at slot 66
 	state, blk3, err := prepareForkchoiceState(ctx, 2*params.BeaconConfig().SlotsPerEpoch+2, [32]byte{'d'}, blk2.Root(), params.BeaconConfig().ZeroHash, 1, 1)
 	require.NoError(t, err)
 	require.NoError(t, f.InsertNode(ctx, state, blk3))
@@ -533,8 +536,11 @@ func TestStore_TargetRootForEpoch(t *testing.T) {
 	dependent, err = f.DependentRoot(1)
 	require.NoError(t, err)
 	require.Equal(t, [32]byte{}, dependent)
+	dependent, err = f.DependentRoot(2)
+	require.NoError(t, err)
+	require.Equal(t, blk1.Root(), dependent)
 
-	// Insert a block for next epoch (slot 0 present)
+	// Insert a block for the next epoch, slot 96 (descends from finalized at slot 33)
 	state, blk4, err := prepareForkchoiceState(ctx, 3*params.BeaconConfig().SlotsPerEpoch, [32]byte{'e'}, blk1.Root(), params.BeaconConfig().ZeroHash, 1, 1)
 	require.NoError(t, err)
 	require.NoError(t, f.InsertNode(ctx, state, blk4))
@@ -551,6 +557,7 @@ func TestStore_TargetRootForEpoch(t *testing.T) {
 	require.NoError(t, err)
 	require.Equal(t, dependent, blk1.Root())
 
+	// Insert a block at slot 97
 	state, blk5, err := prepareForkchoiceState(ctx, 3*params.BeaconConfig().SlotsPerEpoch+1, [32]byte{'f'}, blk4.Root(), params.BeaconConfig().ZeroHash, 1, 1)
 	require.NoError(t, err)
 	require.NoError(t, f.InsertNode(ctx, state, blk5))
@@ -600,12 +607,16 @@ func TestStore_TargetRootForEpoch(t *testing.T) {
 	require.NoError(t, err)
 	require.Equal(t, target, blk1.Root())
 
-	// Prune finalization
+	// Prune finalization, finalize the block at slot 96
 	s.finalizedCheckpoint.Root = blk4.Root()
 	require.NoError(t, s.prune(ctx))
 	target, err = f.TargetRootForEpoch(blk4.Root(), 3)
 	require.NoError(t, err)
 	require.Equal(t, blk4.Root(), target)
+	// Dependent root for the finalized block should be the root of the pruned block at slot 33
+	dependent, err = f.DependentRootForEpoch(blk4.Root(), 3)
+	require.NoError(t, err)
+	require.Equal(t, blk1.Root(), dependent)
 }
 
 func TestStore_DependentRootForEpoch(t *testing.T) {

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

@@ -31,6 +31,7 @@ type Store struct {
 	proposerBoostRoot             [fieldparams.RootLength]byte           // latest block root that was boosted after being received in a timely manner.
 	previousProposerBoostRoot     [fieldparams.RootLength]byte           // previous block root that was boosted after being received in a timely manner.
 	previousProposerBoostScore    uint64                                 // previous proposer boosted root score.
+	finalizedDependentRoot        [fieldparams.RootLength]byte           // dependent root at finalized checkpoint.
 	committeeWeight               uint64                                 // tracks the total active validator balance divided by the number of slots per Epoch.
 	treeRootNode                  *Node                                  // the root node of the store tree.
 	headNode                      *Node                                  // last head Node

beacon-chain/graffiti/graffiti-proposal-brief.md

@@ -0,0 +1,95 @@
+# Graffiti Version Info Implementation
+
+## Summary
+Add automatic EL+CL version info to block graffiti following [ethereum/execution-apis#517](https://github.com/ethereum/execution-apis/pull/517). Uses the [flexible standard](https://hackmd.io/@wmoBhF17RAOH2NZ5bNXJVg/BJX2c9gja) to pack client info into leftover space after user graffiti.
+
+More details: https://github.com/ethereum/execution-apis/blob/main/src/engine/identification.md 
+
+## Implementation
+
+### Core Component: GraffitiInfo Struct
+Thread-safe struct holding version information:
+```go
+const clCode = "PR"
+
+type GraffitiInfo struct {
+    mu           sync.RWMutex
+    userGraffiti string  // From --graffiti flag (set once at startup)
+    clCommit     string  // From version.GetCommitPrefix() helper function
+    elCode       string  // From engine_getClientVersionV1
+    elCommit     string  // From engine_getClientVersionV1
+}
+```
+
+### Flow
+1. **Startup**: Parse flags, create GraffitiInfo with user graffiti and CL info.
+2. **Wiring**: Pass struct to both execution service and RPC validator server
+3. **Runtime**: Execution service goroutine periodically calls `engine_getClientVersionV1` and updates EL fields
+4. **Block Proposal**: RPC validator server calls `GenerateGraffiti()` to get formatted graffiti
+
+### Flexible Graffiti Format
+Packs as much client info as space allows (after user graffiti):
+
+| Available Space | Format | Example |
+|----------------|--------|---------|
+| ≥12 bytes | `EL(2)+commit(4)+CL(2)+commit(4)+user` | `GE168dPR63afBob` |
+| 8-11 bytes | `EL(2)+commit(2)+CL(2)+commit(2)+user` | `GE16PR63my node here` |
+| 4-7 bytes | `EL(2)+CL(2)+user` | `GEPRthis is my graffiti msg` |
+| 2-3 bytes | `EL(2)+user` | `GEalmost full graffiti message` |
+| <2 bytes | user only | `full 32 byte user graffiti here` |
+
+```go
+func (g *GraffitiInfo) GenerateGraffiti() [32]byte {
+    available := 32 - len(userGraffiti)
+
+    if elCode == "" {
+        elCommit2 = elCommit4 = ""
+    }
+
+    switch {
+    case available >= 12:
+        return elCode + elCommit4 + clCode + clCommit4 + userGraffiti
+    case available >= 8:
+        return elCode + elCommit2 + clCode + clCommit2 + userGraffiti
+    case available >= 4:
+        return elCode + clCode + userGraffiti
+    case available >= 2:
+        return elCode + userGraffiti
+    default:
+        return userGraffiti
+    }
+}
+```
+
+### Update Logic
+Single testable function in execution service:
+```go
+func (s *Service) updateGraffitiInfo() {
+    versions, err := s.GetClientVersion(ctx)
+    if err != nil {
+        return  // Keep last good value
+    }
+    if len(versions) == 1 {
+        s.graffitiInfo.UpdateFromEngine(versions[0].Code, versions[0].Commit)
+    }
+}
+```
+
+Goroutine calls this on `slot % 8 == 4` timing (4 times per epoch, avoids slot boundaries).
+
+### Files Changes Required
+
+**New:**
+- `beacon-chain/execution/graffiti_info.go` - The struct and methods
+- `beacon-chain/execution/graffiti_info_test.go` - Unit tests
+- `runtime/version/version.go` - Add `GetCommitPrefix()` helper that extracts first 4 hex chars from the git commit injected via Bazel ldflags at build time
+
+**Modified:**
+- `beacon-chain/execution/service.go` - Add goroutine + updateGraffitiInfo()
+- `beacon-chain/execution/engine_client.go` - Add GetClientVersion() method that does engine call
+- `beacon-chain/rpc/.../validator/proposer.go` - Call GenerateGraffiti()
+- `beacon-chain/node/node.go` - Wire GraffitiInfo to services
+
+### Testing Strategy
+- Unit test GraffitiInfo methods (priority logic, thread safety)
+- Unit test updateGraffitiInfo() with mocked engine client

beacon-chain/p2p/types/object_mapping.go

@@ -204,6 +204,9 @@ func InitializeDataMaps() {
 		bytesutil.ToBytes4(params.BeaconConfig().ElectraForkVersion): func() (interfaces.LightClientOptimisticUpdate, error) {
 			return lightclientConsensusTypes.NewEmptyOptimisticUpdateDeneb(), nil
 		},
+		bytesutil.ToBytes4(params.BeaconConfig().FuluForkVersion): func() (interfaces.LightClientOptimisticUpdate, error) {
+			return lightclientConsensusTypes.NewEmptyOptimisticUpdateDeneb(), nil
+		},
 	}
 
 	// Reset our light client finality update map.
@@ -223,5 +226,8 @@ func InitializeDataMaps() {
 		bytesutil.ToBytes4(params.BeaconConfig().ElectraForkVersion): func() (interfaces.LightClientFinalityUpdate, error) {
 			return lightclientConsensusTypes.NewEmptyFinalityUpdateElectra(), nil
 		},
+		bytesutil.ToBytes4(params.BeaconConfig().FuluForkVersion): func() (interfaces.LightClientFinalityUpdate, error) {
+			return lightclientConsensusTypes.NewEmptyFinalityUpdateElectra(), nil
+		},
 	}
 }

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

@@ -14,6 +14,7 @@ import (
 	"github.com/OffchainLabs/prysm/v7/api"
 	"github.com/OffchainLabs/prysm/v7/api/server/structs"
 	"github.com/OffchainLabs/prysm/v7/beacon-chain/blockchain/kzg"
+	coreblocks "github.com/OffchainLabs/prysm/v7/beacon-chain/core/blocks"
 	corehelpers "github.com/OffchainLabs/prysm/v7/beacon-chain/core/helpers"
 	"github.com/OffchainLabs/prysm/v7/beacon-chain/core/transition"
 	"github.com/OffchainLabs/prysm/v7/beacon-chain/db/filters"
@@ -957,6 +958,13 @@ func (s *Server) validateConsensus(ctx context.Context, b *eth.GenericSignedBeac
 			}
 		}
 	}
+	blockRoot, err := blk.Block().HashTreeRoot()
+	if err != nil {
+		return errors.Wrap(err, "could not hash block")
+	}
+	if err := coreblocks.VerifyBlockSignatureUsingCurrentFork(parentState, blk, blockRoot); err != nil {
+		return errors.Wrap(err, "could not verify block signature")
+	}
 	_, err = transition.ExecuteStateTransition(ctx, parentState, blk)
 	if err != nil {
 		return errors.Wrap(err, "could not execute state transition")

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

@@ -130,6 +130,10 @@ func (s *Server) SubmitAttestationsV2(w http.ResponseWriter, r *http.Request) {
 	ctx, span := trace.StartSpan(r.Context(), "beacon.SubmitAttestationsV2")
 	defer span.End()
 
+	if shared.IsSyncing(ctx, w, s.SyncChecker, s.HeadFetcher, s.TimeFetcher, s.OptimisticModeFetcher) {
+		return
+	}
+
 	versionHeader := r.Header.Get(api.VersionHeader)
 	if versionHeader == "" {
 		httputil.HandleError(w, api.VersionHeader+" header is required", http.StatusBadRequest)
@@ -238,22 +242,14 @@ func (s *Server) handleAttestationsElectra(
 			},
 		})
 
-		targetState, err := s.AttestationStateFetcher.AttestationTargetState(ctx, singleAtt.Data.Target)
-		if err != nil {
-			return nil, nil, errors.Wrap(err, "could not get target state for attestation")
-		}
-		committee, err := corehelpers.BeaconCommitteeFromState(ctx, targetState, singleAtt.Data.Slot, singleAtt.CommitteeId)
-		if err != nil {
-			return nil, nil, errors.Wrap(err, "could not get committee for attestation")
-		}
-		att := singleAtt.ToAttestationElectra(committee)
-
-		wantedEpoch := slots.ToEpoch(att.Data.Slot)
+		// Broadcast first using CommitteeId directly (fast path)
+		// This matches gRPC behavior and avoids blocking on state fetching
+		wantedEpoch := slots.ToEpoch(singleAtt.Data.Slot)
 		vals, err := s.HeadFetcher.HeadValidatorsIndices(ctx, wantedEpoch)
 		if err != nil {
 			return nil, nil, errors.Wrap(err, "could not get head validator indices")
 		}
-		subnet := corehelpers.ComputeSubnetFromCommitteeAndSlot(uint64(len(vals)), att.GetCommitteeIndex(), att.Data.Slot)
+		subnet := corehelpers.ComputeSubnetFromCommitteeAndSlot(uint64(len(vals)), singleAtt.CommitteeId, singleAtt.Data.Slot)
 		if err = s.Broadcaster.BroadcastAttestation(ctx, subnet, singleAtt); err != nil {
 			failedBroadcasts = append(failedBroadcasts, &server.IndexedError{
 				Index:   i,
@@ -264,17 +260,35 @@ func (s *Server) handleAttestationsElectra(
 			}
 			continue
 		}
+	}
 
-		if features.Get().EnableExperimentalAttestationPool {
-			if err = s.AttestationCache.Add(att); err != nil {
-				log.WithError(err).Error("Could not save attestation")
+	// Save to pool after broadcast (slow path - requires state fetching)
+	// Run in goroutine to avoid blocking the HTTP response
+	go func() {
+		for _, singleAtt := range validAttestations {
+			targetState, err := s.AttestationStateFetcher.AttestationTargetState(context.Background(), singleAtt.Data.Target)
+			if err != nil {
+				log.WithError(err).Error("Could not get target state for attestation")
+				continue
 			}
-		} else {
-			if err = s.AttestationsPool.SaveUnaggregatedAttestation(att); err != nil {
-				log.WithError(err).Error("Could not save attestation")
+			committee, err := corehelpers.BeaconCommitteeFromState(context.Background(), targetState, singleAtt.Data.Slot, singleAtt.CommitteeId)
+			if err != nil {
+				log.WithError(err).Error("Could not get committee for attestation")
+				continue
+			}
+			att := singleAtt.ToAttestationElectra(committee)
+
+			if features.Get().EnableExperimentalAttestationPool {
+				if err = s.AttestationCache.Add(att); err != nil {
+					log.WithError(err).Error("Could not save attestation")
+				}
+			} else {
+				if err = s.AttestationsPool.SaveUnaggregatedAttestation(att); err != nil {
+					log.WithError(err).Error("Could not save attestation")
+				}
 			}
 		}
-	}
+	}()
 
 	if len(failedBroadcasts) > 0 {
 		log.WithFields(logrus.Fields{
@@ -470,6 +484,10 @@ func (s *Server) SubmitSyncCommitteeSignatures(w http.ResponseWriter, r *http.Re
 	ctx, span := trace.StartSpan(r.Context(), "beacon.SubmitPoolSyncCommitteeSignatures")
 	defer span.End()
 
+	if shared.IsSyncing(ctx, w, s.SyncChecker, s.HeadFetcher, s.TimeFetcher, s.OptimisticModeFetcher) {
+		return
+	}
+
 	var req structs.SubmitSyncCommitteeSignaturesRequest
 	err := json.NewDecoder(r.Body).Decode(&req.Data)
 	switch {
@@ -711,6 +729,7 @@ func (s *Server) SubmitAttesterSlashingsV2(w http.ResponseWriter, r *http.Reques
 	versionHeader := r.Header.Get(api.VersionHeader)
 	if versionHeader == "" {
 		httputil.HandleError(w, api.VersionHeader+" header is required", http.StatusBadRequest)
+		return
 	}
 	v, err := version.FromString(versionHeader)
 	if err != nil {

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

@@ -26,6 +26,7 @@ import (
 	"github.com/OffchainLabs/prysm/v7/beacon-chain/operations/voluntaryexits/mock"
 	p2pMock "github.com/OffchainLabs/prysm/v7/beacon-chain/p2p/testing"
 	"github.com/OffchainLabs/prysm/v7/beacon-chain/rpc/core"
+	mockSync "github.com/OffchainLabs/prysm/v7/beacon-chain/sync/initial-sync/testing"
 	state_native "github.com/OffchainLabs/prysm/v7/beacon-chain/state/state-native"
 	"github.com/OffchainLabs/prysm/v7/config/params"
 	"github.com/OffchainLabs/prysm/v7/consensus-types/primitives"
@@ -622,6 +623,8 @@ func TestSubmitAttestationsV2(t *testing.T) {
 		HeadFetcher:             chainService,
 		ChainInfoFetcher:        chainService,
 		TimeFetcher:             chainService,
+		OptimisticModeFetcher:   chainService,
+		SyncChecker:             &mockSync.Sync{IsSyncing: false},
 		OperationNotifier:       &blockchainmock.MockOperationNotifier{},
 		AttestationStateFetcher: chainService,
 	}
@@ -654,6 +657,7 @@ func TestSubmitAttestationsV2(t *testing.T) {
 			assert.Equal(t, primitives.Epoch(0), broadcaster.BroadcastAttestations[0].GetData().Source.Epoch)
 			assert.Equal(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2", hexutil.Encode(broadcaster.BroadcastAttestations[0].GetData().Target.Root))
 			assert.Equal(t, primitives.Epoch(0), broadcaster.BroadcastAttestations[0].GetData().Target.Epoch)
+			time.Sleep(100 * time.Millisecond) // Wait for async pool save
 			assert.Equal(t, 1, s.AttestationsPool.UnaggregatedAttestationCount())
 		})
 		t.Run("multiple", func(t *testing.T) {
@@ -673,6 +677,7 @@ func TestSubmitAttestationsV2(t *testing.T) {
 			assert.Equal(t, http.StatusOK, writer.Code)
 			assert.Equal(t, true, broadcaster.BroadcastCalled.Load())
 			assert.Equal(t, 2, broadcaster.NumAttestations())
+			time.Sleep(100 * time.Millisecond) // Wait for async pool save
 			assert.Equal(t, 2, s.AttestationsPool.UnaggregatedAttestationCount())
 		})
 		t.Run("phase0 att post electra", func(t *testing.T) {
@@ -793,6 +798,7 @@ func TestSubmitAttestationsV2(t *testing.T) {
 			assert.Equal(t, primitives.Epoch(0), broadcaster.BroadcastAttestations[0].GetData().Source.Epoch)
 			assert.Equal(t, "0xcf8e0d4e9587369b2301d0790347320302cc0943d5a1884560367e8208d920f2", hexutil.Encode(broadcaster.BroadcastAttestations[0].GetData().Target.Root))
 			assert.Equal(t, primitives.Epoch(0), broadcaster.BroadcastAttestations[0].GetData().Target.Epoch)
+			time.Sleep(100 * time.Millisecond) // Wait for async pool save
 			assert.Equal(t, 1, s.AttestationsPool.UnaggregatedAttestationCount())
 		})
 		t.Run("multiple", func(t *testing.T) {
@@ -812,6 +818,7 @@ func TestSubmitAttestationsV2(t *testing.T) {
 			assert.Equal(t, http.StatusOK, writer.Code)
 			assert.Equal(t, true, broadcaster.BroadcastCalled.Load())
 			assert.Equal(t, 2, broadcaster.NumAttestations())
+			time.Sleep(100 * time.Millisecond) // Wait for async pool save
 			assert.Equal(t, 2, s.AttestationsPool.UnaggregatedAttestationCount())
 		})
 		t.Run("no body", func(t *testing.T) {
@@ -861,6 +868,27 @@ func TestSubmitAttestationsV2(t *testing.T) {
 			assert.Equal(t, true, strings.Contains(e.Failures[0].Message, "Incorrect attestation signature"))
 		})
 	})
+	t.Run("syncing", func(t *testing.T) {
+		chainService := &blockchainmock.ChainService{}
+		s := &Server{
+			HeadFetcher:           chainService,
+			TimeFetcher:           chainService,
+			OptimisticModeFetcher: chainService,
+			SyncChecker:           &mockSync.Sync{IsSyncing: true},
+		}
+
+		var body bytes.Buffer
+		_, err := body.WriteString(singleAtt)
+		require.NoError(t, err)
+		request := httptest.NewRequest(http.MethodPost, "http://example.com", &body)
+		request.Header.Set(api.VersionHeader, version.String(version.Phase0))
+		writer := httptest.NewRecorder()
+		writer.Body = &bytes.Buffer{}
+
+		s.SubmitAttestationsV2(writer, request)
+		assert.Equal(t, http.StatusServiceUnavailable, writer.Code)
+		assert.Equal(t, true, strings.Contains(writer.Body.String(), "Beacon node is currently syncing"))
+	})
 }
 
 func TestListVoluntaryExits(t *testing.T) {
@@ -1057,14 +1085,19 @@ func TestSubmitSyncCommitteeSignatures(t *testing.T) {
 
 	t.Run("single", func(t *testing.T) {
 		broadcaster := &p2pMock.MockBroadcaster{}
+		chainService := &blockchainmock.ChainService{
+			State:                st,
+			SyncCommitteeIndices: []primitives.CommitteeIndex{0},
+		}
 		s := &Server{
+			HeadFetcher:           chainService,
+			TimeFetcher:           chainService,
+			OptimisticModeFetcher: chainService,
+			SyncChecker:           &mockSync.Sync{IsSyncing: false},
 			CoreService: &core.Service{
 				SyncCommitteePool: synccommittee.NewStore(),
 				P2P:               broadcaster,
-				HeadFetcher: &blockchainmock.ChainService{
-					State:                st,
-					SyncCommitteeIndices: []primitives.CommitteeIndex{0},
-				},
+				HeadFetcher:       chainService,
 			},
 		}
 
@@ -1089,14 +1122,19 @@ func TestSubmitSyncCommitteeSignatures(t *testing.T) {
 	})
 	t.Run("multiple", func(t *testing.T) {
 		broadcaster := &p2pMock.MockBroadcaster{}
+		chainService := &blockchainmock.ChainService{
+			State:                st,
+			SyncCommitteeIndices: []primitives.CommitteeIndex{0},
+		}
 		s := &Server{
+			HeadFetcher:           chainService,
+			TimeFetcher:           chainService,
+			OptimisticModeFetcher: chainService,
+			SyncChecker:           &mockSync.Sync{IsSyncing: false},
 			CoreService: &core.Service{
 				SyncCommitteePool: synccommittee.NewStore(),
 				P2P:               broadcaster,
-				HeadFetcher: &blockchainmock.ChainService{
-					State:                st,
-					SyncCommitteeIndices: []primitives.CommitteeIndex{0},
-				},
+				HeadFetcher:       chainService,
 			},
 		}
 
@@ -1120,13 +1158,18 @@ func TestSubmitSyncCommitteeSignatures(t *testing.T) {
 	})
 	t.Run("invalid", func(t *testing.T) {
 		broadcaster := &p2pMock.MockBroadcaster{}
+		chainService := &blockchainmock.ChainService{
+			State: st,
+		}
 		s := &Server{
+			HeadFetcher:           chainService,
+			TimeFetcher:           chainService,
+			OptimisticModeFetcher: chainService,
+			SyncChecker:           &mockSync.Sync{IsSyncing: false},
 			CoreService: &core.Service{
 				SyncCommitteePool: synccommittee.NewStore(),
 				P2P:               broadcaster,
-				HeadFetcher: &blockchainmock.ChainService{
-					State: st,
-				},
+				HeadFetcher:       chainService,
 			},
 		}
 
@@ -1149,7 +1192,13 @@ func TestSubmitSyncCommitteeSignatures(t *testing.T) {
 		assert.Equal(t, false, broadcaster.BroadcastCalled.Load())
 	})
 	t.Run("empty", func(t *testing.T) {
-		s := &Server{}
+		chainService := &blockchainmock.ChainService{State: st}
+		s := &Server{
+			HeadFetcher:           chainService,
+			TimeFetcher:           chainService,
+			OptimisticModeFetcher: chainService,
+			SyncChecker:           &mockSync.Sync{IsSyncing: false},
+		}
 
 		var body bytes.Buffer
 		_, err := body.WriteString("[]")
@@ -1166,7 +1215,13 @@ func TestSubmitSyncCommitteeSignatures(t *testing.T) {
 		assert.Equal(t, true, strings.Contains(e.Message, "No data submitted"))
 	})
 	t.Run("no body", func(t *testing.T) {
-		s := &Server{}
+		chainService := &blockchainmock.ChainService{State: st}
+		s := &Server{
+			HeadFetcher:           chainService,
+			TimeFetcher:           chainService,
+			OptimisticModeFetcher: chainService,
+			SyncChecker:           &mockSync.Sync{IsSyncing: false},
+		}
 
 		request := httptest.NewRequest(http.MethodPost, "http://example.com", nil)
 		writer := httptest.NewRecorder()
@@ -1179,6 +1234,26 @@ func TestSubmitSyncCommitteeSignatures(t *testing.T) {
 		assert.Equal(t, http.StatusBadRequest, e.Code)
 		assert.Equal(t, true, strings.Contains(e.Message, "No data submitted"))
 	})
+	t.Run("syncing", func(t *testing.T) {
+		chainService := &blockchainmock.ChainService{State: st}
+		s := &Server{
+			HeadFetcher:           chainService,
+			TimeFetcher:           chainService,
+			OptimisticModeFetcher: chainService,
+			SyncChecker:           &mockSync.Sync{IsSyncing: true},
+		}
+
+		var body bytes.Buffer
+		_, err := body.WriteString(singleSyncCommitteeMsg)
+		require.NoError(t, err)
+		request := httptest.NewRequest(http.MethodPost, "http://example.com", &body)
+		writer := httptest.NewRecorder()
+		writer.Body = &bytes.Buffer{}
+
+		s.SubmitSyncCommitteeSignatures(writer, request)
+		assert.Equal(t, http.StatusServiceUnavailable, writer.Code)
+		assert.Equal(t, true, strings.Contains(writer.Body.String(), "Beacon node is currently syncing"))
+	})
 }
 
 func TestListBLSToExecutionChanges(t *testing.T) {
@@ -2112,6 +2187,33 @@ func TestSubmitAttesterSlashingsV2(t *testing.T) {
 		assert.Equal(t, http.StatusBadRequest, e.Code)
 		assert.StringContains(t, "Invalid attester slashing", e.Message)
 	})
+
+	t.Run("missing-version-header", func(t *testing.T) {
+		bs, err := util.NewBeaconStateElectra()
+		require.NoError(t, err)
+
+		broadcaster := &p2pMock.MockBroadcaster{}
+		s := &Server{
+			ChainInfoFetcher: &blockchainmock.ChainService{State: bs},
+			SlashingsPool:    &slashingsmock.PoolMock{},
+			Broadcaster:      broadcaster,
+		}
+
+		var body bytes.Buffer
+		_, err = body.WriteString(invalidAttesterSlashing)
+		require.NoError(t, err)
+		request := httptest.NewRequest(http.MethodPost, "http://example.com/beacon/pool/attester_slashings", &body)
+		// Intentionally do not set api.VersionHeader to verify missing header handling.
+		writer := httptest.NewRecorder()
+		writer.Body = &bytes.Buffer{}
+
+		s.SubmitAttesterSlashingsV2(writer, request)
+		require.Equal(t, http.StatusBadRequest, writer.Code)
+		e := &httputil.DefaultJsonError{}
+		require.NoError(t, json.Unmarshal(writer.Body.Bytes(), e))
+		assert.Equal(t, http.StatusBadRequest, e.Code)
+		assert.StringContains(t, api.VersionHeader+" header is required", e.Message)
+	})
 }
 
 func TestSubmitProposerSlashing_InvalidSlashing(t *testing.T) {

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

@@ -654,6 +654,10 @@ func (m *futureSyncMockFetcher) StateBySlot(context.Context, primitives.Slot) (s
 	return m.BeaconState, nil
 }
 
+func (m *futureSyncMockFetcher) StateByEpoch(context.Context, primitives.Epoch) (state.BeaconState, error) {
+	return m.BeaconState, nil
+}
+
 func TestGetSyncCommittees_Future(t *testing.T) {
 	st, _ := util.DeterministicGenesisStateAltair(t, params.BeaconConfig().SyncCommitteeSize)
 	syncCommittee := make([][]byte, params.BeaconConfig().SyncCommitteeSize)

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

@@ -40,6 +40,7 @@ func GetForkSchedule(w http.ResponseWriter, r *http.Request) {
 		httputil.WriteJson(w, &structs.GetForkScheduleResponse{
 			Data: data,
 		})
+		return
 	}
 	previous := schedule[0]
 	for _, entry := range schedule {

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

@@ -116,6 +116,7 @@ func (s *Server) GetLightClientUpdatesByRange(w http.ResponseWriter, req *http.R
 		for _, update := range updates {
 			if ctx.Err() != nil {
 				httputil.HandleError(w, "Context error: "+ctx.Err().Error(), http.StatusInternalServerError)
+				return
 			}
 
 			updateSlot := update.AttestedHeader().Beacon().Slot
@@ -131,12 +132,15 @@ func (s *Server) GetLightClientUpdatesByRange(w http.ResponseWriter, req *http.R
 			chunkLength = ssz.MarshalUint64(chunkLength, uint64(len(updateSSZ)+4))
 			if _, err := w.Write(chunkLength); err != nil {
 				httputil.HandleError(w, "Could not write chunk length: "+err.Error(), http.StatusInternalServerError)
+				return
 			}
 			if _, err := w.Write(updateEntry.ForkDigest[:]); err != nil {
 				httputil.HandleError(w, "Could not write fork digest: "+err.Error(), http.StatusInternalServerError)
+				return
 			}
 			if _, err := w.Write(updateSSZ); err != nil {
 				httputil.HandleError(w, "Could not write update SSZ: "+err.Error(), http.StatusInternalServerError)
+				return
 			}
 		}
 	} else {
@@ -145,6 +149,7 @@ func (s *Server) GetLightClientUpdatesByRange(w http.ResponseWriter, req *http.R
 		for _, update := range updates {
 			if ctx.Err() != nil {
 				httputil.HandleError(w, "Context error: "+ctx.Err().Error(), http.StatusInternalServerError)
+				return
 			}
 
 			updateJson, err := structs.LightClientUpdateFromConsensus(update)

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

@@ -132,6 +132,7 @@ func (s *Server) GetHealth(w http.ResponseWriter, r *http.Request) {
 	optimistic, err := s.OptimisticModeFetcher.IsOptimistic(ctx)
 	if err != nil {
 		httputil.HandleError(w, "Could not check optimistic status: "+err.Error(), http.StatusInternalServerError)
+		return
 	}
 	if s.SyncChecker.Synced() && !optimistic {
 		return

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

@@ -228,7 +228,7 @@ func (s *Server) attRewardsState(w http.ResponseWriter, r *http.Request) (state.
 	}
 	st, err := s.Stater.StateBySlot(r.Context(), nextEpochEnd)
 	if err != nil {
-		httputil.HandleError(w, "Could not get state for epoch's starting slot: "+err.Error(), http.StatusInternalServerError)
+		shared.WriteStateFetchError(w, err)
 		return nil, false
 	}
 	return st, true

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

@@ -19,7 +19,6 @@ go_library(
         "//beacon-chain/cache:go_default_library",
         "//beacon-chain/core/feed/operation:go_default_library",
         "//beacon-chain/core/helpers:go_default_library",
-        "//beacon-chain/core/transition:go_default_library",
         "//beacon-chain/db:go_default_library",
         "//beacon-chain/operations/attestations:go_default_library",
         "//beacon-chain/operations/synccommittee:go_default_library",
@@ -78,6 +77,7 @@ go_test(
         "//beacon-chain/rpc/core:go_default_library",
         "//beacon-chain/rpc/eth/rewards/testing:go_default_library",
         "//beacon-chain/rpc/eth/shared/testing:go_default_library",
+        "//beacon-chain/rpc/lookup:go_default_library",
         "//beacon-chain/rpc/testutil:go_default_library",
         "//beacon-chain/state:go_default_library",
         "//beacon-chain/state/stategen:go_default_library",

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

@@ -19,7 +19,6 @@ import (
 	"github.com/OffchainLabs/prysm/v7/beacon-chain/builder"
 	"github.com/OffchainLabs/prysm/v7/beacon-chain/cache"
 	"github.com/OffchainLabs/prysm/v7/beacon-chain/core/helpers"
-	"github.com/OffchainLabs/prysm/v7/beacon-chain/core/transition"
 	"github.com/OffchainLabs/prysm/v7/beacon-chain/rpc/core"
 	rpchelpers "github.com/OffchainLabs/prysm/v7/beacon-chain/rpc/eth/helpers"
 	"github.com/OffchainLabs/prysm/v7/beacon-chain/rpc/eth/shared"
@@ -898,20 +897,15 @@ func (s *Server) GetAttesterDuties(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	var startSlot primitives.Slot
+	// For next epoch requests, we use the current epoch's state since committee
+	// assignments for next epoch can be computed from current epoch's state.
+	epochForState := requestedEpoch
 	if requestedEpoch == nextEpoch {
-		startSlot, err = slots.EpochStart(currentEpoch)
-	} else {
-		startSlot, err = slots.EpochStart(requestedEpoch)
+		epochForState = currentEpoch
 	}
+	st, err := s.Stater.StateByEpoch(ctx, epochForState)
 	if err != nil {
-		httputil.HandleError(w, fmt.Sprintf("Could not get start slot from epoch %d: %v", requestedEpoch, err), http.StatusInternalServerError)
-		return
-	}
-
-	st, err := s.Stater.StateBySlot(ctx, startSlot)
-	if err != nil {
-		httputil.HandleError(w, "Could not get state: "+err.Error(), http.StatusInternalServerError)
+		shared.WriteStateFetchError(w, err)
 		return
 	}
 
@@ -1020,39 +1014,11 @@ func (s *Server) GetProposerDuties(w http.ResponseWriter, r *http.Request) {
 		nextEpochLookahead = true
 	}
 
-	epochStartSlot, err := slots.EpochStart(requestedEpoch)
+	st, err := s.Stater.StateByEpoch(ctx, requestedEpoch)
 	if err != nil {
-		httputil.HandleError(w, fmt.Sprintf("Could not get start slot of epoch %d: %v", requestedEpoch, err), http.StatusInternalServerError)
+		shared.WriteStateFetchError(w, err)
 		return
 	}
-	var st state.BeaconState
-	// if the requested epoch is new, use the head state and the next slot cache
-	if requestedEpoch < currentEpoch {
-		st, err = s.Stater.StateBySlot(ctx, epochStartSlot)
-		if err != nil {
-			httputil.HandleError(w, fmt.Sprintf("Could not get state for slot %d: %v ", epochStartSlot, err), http.StatusInternalServerError)
-			return
-		}
-	} else {
-		st, err = s.HeadFetcher.HeadState(ctx)
-		if err != nil {
-			httputil.HandleError(w, fmt.Sprintf("Could not get head state: %v ", err), http.StatusInternalServerError)
-			return
-		}
-		// Notice that even for Fulu requests for the next epoch, we are only advancing the state to the start of the current epoch.
-		if st.Slot() < epochStartSlot {
-			headRoot, err := s.HeadFetcher.HeadRoot(ctx)
-			if err != nil {
-				httputil.HandleError(w, fmt.Sprintf("Could not get head root: %v ", err), http.StatusInternalServerError)
-				return
-			}
-			st, err = transition.ProcessSlotsUsingNextSlotCache(ctx, st, headRoot, epochStartSlot)
-			if err != nil {
-				httputil.HandleError(w, fmt.Sprintf("Could not process slots up to %d: %v ", epochStartSlot, err), http.StatusInternalServerError)
-				return
-			}
-		}
-	}
 
 	var assignments map[primitives.ValidatorIndex][]primitives.Slot
 	if nextEpochLookahead {
@@ -1103,7 +1069,8 @@ func (s *Server) GetProposerDuties(w http.ResponseWriter, r *http.Request) {
 		httputil.HandleError(w, "Could not check optimistic status: "+err.Error(), http.StatusInternalServerError)
 		return
 	}
-	if !sortProposerDuties(w, duties) {
+	if err = sortProposerDuties(duties); err != nil {
+		httputil.HandleError(w, "Could not sort proposer duties: "+err.Error(), http.StatusInternalServerError)
 		return
 	}
 
@@ -1174,14 +1141,10 @@ func (s *Server) GetSyncCommitteeDuties(w http.ResponseWriter, r *http.Request)
 	}
 
 	startingEpoch := min(requestedEpoch, currentEpoch)
-	slot, err := slots.EpochStart(startingEpoch)
+
+	st, err := s.Stater.StateByEpoch(ctx, startingEpoch)
 	if err != nil {
-		httputil.HandleError(w, "Could not get sync committee slot: "+err.Error(), http.StatusInternalServerError)
-		return
-	}
-	st, err := s.Stater.State(ctx, []byte(strconv.FormatUint(uint64(slot), 10)))
-	if err != nil {
-		httputil.HandleError(w, "Could not get sync committee state: "+err.Error(), http.StatusInternalServerError)
+		shared.WriteStateFetchError(w, err)
 		return
 	}
 
@@ -1327,7 +1290,7 @@ func (s *Server) GetLiveness(w http.ResponseWriter, r *http.Request) {
 		}
 		st, err = s.Stater.StateBySlot(ctx, epochEnd)
 		if err != nil {
-			httputil.HandleError(w, "Could not get slot for requested epoch: "+err.Error(), http.StatusInternalServerError)
+			shared.WriteStateFetchError(w, err)
 			return
 		}
 		participation, err = st.CurrentEpochParticipation()
@@ -1447,22 +1410,20 @@ func syncCommitteeDutiesAndVals(
 	return duties, vals, nil
 }
 
-func sortProposerDuties(w http.ResponseWriter, duties []*structs.ProposerDuty) bool {
-	ok := true
+func sortProposerDuties(duties []*structs.ProposerDuty) error {
+	var err error
 	sort.Slice(duties, func(i, j int) bool {
-		si, err := strconv.ParseUint(duties[i].Slot, 10, 64)
-		if err != nil {
-			httputil.HandleError(w, "Could not parse slot: "+err.Error(), http.StatusInternalServerError)
-			ok = false
+		si, parseErr := strconv.ParseUint(duties[i].Slot, 10, 64)
+		if parseErr != nil {
+			err = errors.Wrap(parseErr, "could not parse slot")
 			return false
 		}
-		sj, err := strconv.ParseUint(duties[j].Slot, 10, 64)
-		if err != nil {
-			httputil.HandleError(w, "Could not parse slot: "+err.Error(), http.StatusInternalServerError)
-			ok = false
+		sj, parseErr := strconv.ParseUint(duties[j].Slot, 10, 64)
+		if parseErr != nil {
+			err = errors.Wrap(parseErr, "could not parse slot")
 			return false
 		}
 		return si < sj
 	})
-	return ok
+	return err
 }

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

@@ -25,6 +25,7 @@ import (
 	"github.com/OffchainLabs/prysm/v7/beacon-chain/operations/synccommittee"
 	p2pmock "github.com/OffchainLabs/prysm/v7/beacon-chain/p2p/testing"
 	"github.com/OffchainLabs/prysm/v7/beacon-chain/rpc/core"
+	"github.com/OffchainLabs/prysm/v7/beacon-chain/rpc/lookup"
 	"github.com/OffchainLabs/prysm/v7/beacon-chain/rpc/testutil"
 	"github.com/OffchainLabs/prysm/v7/beacon-chain/state"
 	"github.com/OffchainLabs/prysm/v7/beacon-chain/state/stategen"
@@ -2006,6 +2007,7 @@ func TestGetAttesterDuties(t *testing.T) {
 		TimeFetcher:           chain,
 		SyncChecker:           &mockSync.Sync{IsSyncing: false},
 		OptimisticModeFetcher: chain,
+		HeadFetcher:           chain,
 		BeaconDB:              db,
 	}
 
@@ -2184,6 +2186,7 @@ func TestGetAttesterDuties(t *testing.T) {
 			Stater:                &testutil.MockStater{StatesBySlot: map[primitives.Slot]state.BeaconState{0: bs}},
 			TimeFetcher:           chain,
 			OptimisticModeFetcher: chain,
+			HeadFetcher:           chain,
 			SyncChecker:           &mockSync.Sync{IsSyncing: false},
 			BeaconDB:              db,
 		}
@@ -2224,6 +2227,62 @@ func TestGetAttesterDuties(t *testing.T) {
 		require.NoError(t, json.Unmarshal(writer.Body.Bytes(), e))
 		assert.Equal(t, http.StatusServiceUnavailable, e.Code)
 	})
+	t.Run("state not found returns 404", func(t *testing.T) {
+		chainSlot := primitives.Slot(0)
+		chain := &mockChain.ChainService{
+			State: bs, Root: genesisRoot[:], Slot: &chainSlot,
+		}
+		stateNotFoundErr := lookup.NewStateNotFoundError(8192, []byte("test"))
+		s := &Server{
+			Stater:                &testutil.MockStater{CustomError: &stateNotFoundErr},
+			TimeFetcher:           chain,
+			SyncChecker:           &mockSync.Sync{IsSyncing: false},
+			OptimisticModeFetcher: chain,
+			HeadFetcher:           chain,
+		}
+
+		var body bytes.Buffer
+		_, err = body.WriteString("[\"0\"]")
+		require.NoError(t, err)
+		request := httptest.NewRequest(http.MethodGet, "http://www.example.com/eth/v1/validator/duties/attester/{epoch}", &body)
+		request.SetPathValue("epoch", "0")
+		writer := httptest.NewRecorder()
+		writer.Body = &bytes.Buffer{}
+
+		s.GetAttesterDuties(writer, request)
+		assert.Equal(t, http.StatusNotFound, writer.Code)
+		e := &httputil.DefaultJsonError{}
+		require.NoError(t, json.Unmarshal(writer.Body.Bytes(), e))
+		assert.Equal(t, http.StatusNotFound, e.Code)
+		assert.StringContains(t, "State not found", e.Message)
+	})
+	t.Run("state fetch error returns 500", func(t *testing.T) {
+		chainSlot := primitives.Slot(0)
+		chain := &mockChain.ChainService{
+			State: bs, Root: genesisRoot[:], Slot: &chainSlot,
+		}
+		s := &Server{
+			Stater:                &testutil.MockStater{CustomError: errors.New("internal error")},
+			TimeFetcher:           chain,
+			SyncChecker:           &mockSync.Sync{IsSyncing: false},
+			OptimisticModeFetcher: chain,
+			HeadFetcher:           chain,
+		}
+
+		var body bytes.Buffer
+		_, err = body.WriteString("[\"0\"]")
+		require.NoError(t, err)
+		request := httptest.NewRequest(http.MethodGet, "http://www.example.com/eth/v1/validator/duties/attester/{epoch}", &body)
+		request.SetPathValue("epoch", "0")
+		writer := httptest.NewRecorder()
+		writer.Body = &bytes.Buffer{}
+
+		s.GetAttesterDuties(writer, request)
+		assert.Equal(t, http.StatusInternalServerError, writer.Code)
+		e := &httputil.DefaultJsonError{}
+		require.NoError(t, json.Unmarshal(writer.Body.Bytes(), e))
+		assert.Equal(t, http.StatusInternalServerError, e.Code)
+	})
 }
 
 func TestGetProposerDuties(t *testing.T) {
@@ -2427,6 +2486,60 @@ func TestGetProposerDuties(t *testing.T) {
 		require.NoError(t, json.Unmarshal(writer.Body.Bytes(), e))
 		assert.Equal(t, http.StatusServiceUnavailable, e.Code)
 	})
+	t.Run("state not found returns 404", func(t *testing.T) {
+		bs, err := transition.GenesisBeaconState(t.Context(), deposits, 0, eth1Data)
+		require.NoError(t, err)
+		chainSlot := primitives.Slot(0)
+		chain := &mockChain.ChainService{
+			State: bs, Root: genesisRoot[:], Slot: &chainSlot,
+		}
+		stateNotFoundErr := lookup.NewStateNotFoundError(8192, []byte("test"))
+		s := &Server{
+			Stater:                &testutil.MockStater{CustomError: &stateNotFoundErr},
+			TimeFetcher:           chain,
+			SyncChecker:           &mockSync.Sync{IsSyncing: false},
+			OptimisticModeFetcher: chain,
+			HeadFetcher:           chain,
+		}
+
+		request := httptest.NewRequest(http.MethodGet, "http://www.example.com/eth/v1/validator/duties/proposer/{epoch}", nil)
+		request.SetPathValue("epoch", "0")
+		writer := httptest.NewRecorder()
+		writer.Body = &bytes.Buffer{}
+
+		s.GetProposerDuties(writer, request)
+		assert.Equal(t, http.StatusNotFound, writer.Code)
+		e := &httputil.DefaultJsonError{}
+		require.NoError(t, json.Unmarshal(writer.Body.Bytes(), e))
+		assert.Equal(t, http.StatusNotFound, e.Code)
+		assert.StringContains(t, "State not found", e.Message)
+	})
+	t.Run("state fetch error returns 500", func(t *testing.T) {
+		bs, err := transition.GenesisBeaconState(t.Context(), deposits, 0, eth1Data)
+		require.NoError(t, err)
+		chainSlot := primitives.Slot(0)
+		chain := &mockChain.ChainService{
+			State: bs, Root: genesisRoot[:], Slot: &chainSlot,
+		}
+		s := &Server{
+			Stater:                &testutil.MockStater{CustomError: errors.New("internal error")},
+			TimeFetcher:           chain,
+			SyncChecker:           &mockSync.Sync{IsSyncing: false},
+			OptimisticModeFetcher: chain,
+			HeadFetcher:           chain,
+		}
+
+		request := httptest.NewRequest(http.MethodGet, "http://www.example.com/eth/v1/validator/duties/proposer/{epoch}", nil)
+		request.SetPathValue("epoch", "0")
+		writer := httptest.NewRecorder()
+		writer.Body = &bytes.Buffer{}
+
+		s.GetProposerDuties(writer, request)
+		assert.Equal(t, http.StatusInternalServerError, writer.Code)
+		e := &httputil.DefaultJsonError{}
+		require.NoError(t, json.Unmarshal(writer.Body.Bytes(), e))
+		assert.Equal(t, http.StatusInternalServerError, e.Code)
+	})
 }
 
 func TestGetSyncCommitteeDuties(t *testing.T) {
@@ -2457,7 +2570,7 @@ func TestGetSyncCommitteeDuties(t *testing.T) {
 	}
 	require.NoError(t, st.SetNextSyncCommittee(nextCommittee))
 
-	mockChainService := &mockChain.ChainService{Genesis: genesisTime}
+	mockChainService := &mockChain.ChainService{Genesis: genesisTime, State: st}
 	s := &Server{
 		Stater:                &testutil.MockStater{BeaconState: st},
 		SyncChecker:           &mockSync.Sync{IsSyncing: false},
@@ -2648,7 +2761,7 @@ func TestGetSyncCommitteeDuties(t *testing.T) {
 				return newSyncPeriodSt
 			}
 		}
-		mockChainService := &mockChain.ChainService{Genesis: genesisTime, Slot: &newSyncPeriodStartSlot}
+		mockChainService := &mockChain.ChainService{Genesis: genesisTime, Slot: &newSyncPeriodStartSlot, State: newSyncPeriodSt}
 		s := &Server{
 			Stater:                &testutil.MockStater{BeaconState: stateFetchFn(newSyncPeriodStartSlot)},
 			SyncChecker:           &mockSync.Sync{IsSyncing: false},
@@ -2729,8 +2842,7 @@ func TestGetSyncCommitteeDuties(t *testing.T) {
 		slot, err := slots.EpochStart(1)
 		require.NoError(t, err)
 
-		st2, err := util.NewBeaconStateBellatrix()
-		require.NoError(t, err)
+		st2 := st.Copy()
 		require.NoError(t, st2.SetSlot(slot))
 
 		mockChainService := &mockChain.ChainService{
@@ -2744,7 +2856,7 @@ func TestGetSyncCommitteeDuties(t *testing.T) {
 			State: st2,
 		}
 		s := &Server{
-			Stater:                &testutil.MockStater{BeaconState: st},
+			Stater:                &testutil.MockStater{BeaconState: st2},
 			SyncChecker:           &mockSync.Sync{IsSyncing: false},
 			TimeFetcher:           mockChainService,
 			HeadFetcher:           mockChainService,
@@ -2789,6 +2901,62 @@ func TestGetSyncCommitteeDuties(t *testing.T) {
 		require.NoError(t, json.Unmarshal(writer.Body.Bytes(), e))
 		assert.Equal(t, http.StatusServiceUnavailable, e.Code)
 	})
+	t.Run("state not found returns 404", func(t *testing.T) {
+		slot := 2 * params.BeaconConfig().SlotsPerEpoch
+		chainService := &mockChain.ChainService{
+			Slot: &slot,
+		}
+		stateNotFoundErr := lookup.NewStateNotFoundError(8192, []byte("test"))
+		s := &Server{
+			Stater:                &testutil.MockStater{CustomError: &stateNotFoundErr},
+			TimeFetcher:           chainService,
+			SyncChecker:           &mockSync.Sync{IsSyncing: false},
+			OptimisticModeFetcher: chainService,
+			HeadFetcher:           chainService,
+		}
+
+		var body bytes.Buffer
+		_, err := body.WriteString("[\"1\"]")
+		require.NoError(t, err)
+		request := httptest.NewRequest(http.MethodGet, "http://www.example.com/eth/v1/validator/duties/sync/{epoch}", &body)
+		request.SetPathValue("epoch", "1")
+		writer := httptest.NewRecorder()
+		writer.Body = &bytes.Buffer{}
+
+		s.GetSyncCommitteeDuties(writer, request)
+		assert.Equal(t, http.StatusNotFound, writer.Code)
+		e := &httputil.DefaultJsonError{}
+		require.NoError(t, json.Unmarshal(writer.Body.Bytes(), e))
+		assert.Equal(t, http.StatusNotFound, e.Code)
+		assert.StringContains(t, "State not found", e.Message)
+	})
+	t.Run("state fetch error returns 500", func(t *testing.T) {
+		slot := 2 * params.BeaconConfig().SlotsPerEpoch
+		chainService := &mockChain.ChainService{
+			Slot: &slot,
+		}
+		s := &Server{
+			Stater:                &testutil.MockStater{CustomError: errors.New("internal error")},
+			TimeFetcher:           chainService,
+			SyncChecker:           &mockSync.Sync{IsSyncing: false},
+			OptimisticModeFetcher: chainService,
+			HeadFetcher:           chainService,
+		}
+
+		var body bytes.Buffer
+		_, err := body.WriteString("[\"1\"]")
+		require.NoError(t, err)
+		request := httptest.NewRequest(http.MethodGet, "http://www.example.com/eth/v1/validator/duties/sync/{epoch}", &body)
+		request.SetPathValue("epoch", "1")
+		writer := httptest.NewRecorder()
+		writer.Body = &bytes.Buffer{}
+
+		s.GetSyncCommitteeDuties(writer, request)
+		assert.Equal(t, http.StatusInternalServerError, writer.Code)
+		e := &httputil.DefaultJsonError{}
+		require.NoError(t, json.Unmarshal(writer.Body.Bytes(), e))
+		assert.Equal(t, http.StatusInternalServerError, e.Code)
+	})
 }
 
 func TestPrepareBeaconProposer(t *testing.T) {

beacon-chain/rpc/lookup/BUILD.bazel

@@ -11,6 +11,7 @@ go_library(
     deps = [
         "//beacon-chain/blockchain:go_default_library",
         "//beacon-chain/core/peerdas:go_default_library",
+        "//beacon-chain/core/transition:go_default_library",
         "//beacon-chain/db:go_default_library",
         "//beacon-chain/db/filesystem:go_default_library",
         "//beacon-chain/rpc/core:go_default_library",

beacon-chain/rpc/lookup/stater.go

@@ -8,6 +8,7 @@ import (
 	"strings"
 
 	"github.com/OffchainLabs/prysm/v7/beacon-chain/blockchain"
+	"github.com/OffchainLabs/prysm/v7/beacon-chain/core/transition"
 	"github.com/OffchainLabs/prysm/v7/beacon-chain/db"
 	"github.com/OffchainLabs/prysm/v7/beacon-chain/state"
 	"github.com/OffchainLabs/prysm/v7/beacon-chain/state/stategen"
@@ -82,8 +83,8 @@ type StateRootNotFoundError struct {
 }
 
 // NewStateRootNotFoundError creates a new error instance.
-func NewStateRootNotFoundError(stateRootsSize int) StateNotFoundError {
-	return StateNotFoundError{
+func NewStateRootNotFoundError(stateRootsSize int) StateRootNotFoundError {
+	return StateRootNotFoundError{
 		message: fmt.Sprintf("state root not found in the last %d state roots", stateRootsSize),
 	}
 }
@@ -98,6 +99,7 @@ type Stater interface {
 	State(ctx context.Context, id []byte) (state.BeaconState, error)
 	StateRoot(ctx context.Context, id []byte) ([]byte, error)
 	StateBySlot(ctx context.Context, slot primitives.Slot) (state.BeaconState, error)
+	StateByEpoch(ctx context.Context, epoch primitives.Epoch) (state.BeaconState, error)
 }
 
 // BeaconDbStater is an implementation of Stater. It retrieves states from the beacon chain database.
@@ -267,6 +269,46 @@ func (p *BeaconDbStater) StateBySlot(ctx context.Context, target primitives.Slot
 	return st, nil
 }
 
+// StateByEpoch returns the state for the start of the requested epoch.
+// For current or next epoch, it uses the head state and next slot cache for efficiency.
+// For past epochs, it replays blocks from the most recent canonical state.
+func (p *BeaconDbStater) StateByEpoch(ctx context.Context, epoch primitives.Epoch) (state.BeaconState, error) {
+	ctx, span := trace.StartSpan(ctx, "statefetcher.StateByEpoch")
+	defer span.End()
+
+	targetSlot, err := slots.EpochStart(epoch)
+	if err != nil {
+		return nil, errors.Wrap(err, "could not get epoch start slot")
+	}
+
+	currentSlot := p.GenesisTimeFetcher.CurrentSlot()
+	currentEpoch := slots.ToEpoch(currentSlot)
+
+	// For past epochs, use the replay mechanism
+	if epoch < currentEpoch {
+		return p.StateBySlot(ctx, targetSlot)
+	}
+
+	// For current or next epoch, use head state + next slot cache (much faster)
+	headState, err := p.ChainInfoFetcher.HeadState(ctx)
+	if err != nil {
+		return nil, errors.Wrap(err, "could not get head state")
+	}
+
+	// If head state is already at or past the target slot, return it
+	if headState.Slot() >= targetSlot {
+		return headState, nil
+	}
+
+	// Process slots using the next slot cache
+	headRoot := p.ChainInfoFetcher.CachedHeadRoot()
+	st, err := transition.ProcessSlotsUsingNextSlotCache(ctx, headState, headRoot[:], targetSlot)
+	if err != nil {
+		return nil, errors.Wrapf(err, "could not process slots up to %d", targetSlot)
+	}
+	return st, nil
+}
+
 func (p *BeaconDbStater) headStateRoot(ctx context.Context) ([]byte, error) {
 	b, err := p.ChainInfoFetcher.HeadBlock(ctx)
 	if err != nil {

beacon-chain/rpc/lookup/stater_test.go

@@ -444,3 +444,111 @@ func TestStateBySlot_AfterHeadSlot(t *testing.T) {
 	require.NoError(t, err)
 	assert.Equal(t, primitives.Slot(101), st.Slot())
 }
+
+func TestStateByEpoch(t *testing.T) {
+	ctx := t.Context()
+	slotsPerEpoch := params.BeaconConfig().SlotsPerEpoch
+
+	t.Run("current epoch uses head state", func(t *testing.T) {
+		// Head is at slot 5 (epoch 0), requesting epoch 0
+		headSlot := primitives.Slot(5)
+		headSt, err := statenative.InitializeFromProtoPhase0(&ethpb.BeaconState{Slot: headSlot})
+		require.NoError(t, err)
+
+		currentSlot := headSlot
+		mock := &chainMock.ChainService{State: headSt, Slot: &currentSlot}
+		p := BeaconDbStater{ChainInfoFetcher: mock, GenesisTimeFetcher: mock}
+
+		st, err := p.StateByEpoch(ctx, 0)
+		require.NoError(t, err)
+		// Should return head state since it's already past epoch start
+		assert.Equal(t, headSlot, st.Slot())
+	})
+
+	t.Run("current epoch processes slots to epoch start", func(t *testing.T) {
+		// Head is at slot 5 (epoch 0), requesting epoch 1
+		// Current slot is 32 (epoch 1), so epoch 1 is current epoch
+		headSlot := primitives.Slot(5)
+		headSt, err := statenative.InitializeFromProtoPhase0(&ethpb.BeaconState{Slot: headSlot})
+		require.NoError(t, err)
+
+		currentSlot := slotsPerEpoch // slot 32, epoch 1
+		mock := &chainMock.ChainService{State: headSt, Slot: &currentSlot}
+		p := BeaconDbStater{ChainInfoFetcher: mock, GenesisTimeFetcher: mock}
+
+		// Note: This will fail since ProcessSlotsUsingNextSlotCache requires proper setup
+		// In real usage, the transition package handles this properly
+		_, err = p.StateByEpoch(ctx, 1)
+		// The error is expected since we don't have a fully initialized beacon state
+		// that can process slots (missing committees, etc.)
+		assert.NotNil(t, err)
+	})
+
+	t.Run("past epoch uses replay", func(t *testing.T) {
+		// Head is at epoch 2, requesting epoch 0 (past)
+		headSlot := slotsPerEpoch * 2 // slot 64, epoch 2
+		headSt, err := statenative.InitializeFromProtoPhase0(&ethpb.BeaconState{Slot: headSlot})
+		require.NoError(t, err)
+
+		pastEpochSt, err := statenative.InitializeFromProtoPhase0(&ethpb.BeaconState{Slot: 0})
+		require.NoError(t, err)
+
+		currentSlot := headSlot
+		mock := &chainMock.ChainService{State: headSt, Slot: &currentSlot}
+		mockReplayer := mockstategen.NewReplayerBuilder()
+		mockReplayer.SetMockStateForSlot(pastEpochSt, 0)
+		p := BeaconDbStater{ChainInfoFetcher: mock, GenesisTimeFetcher: mock, ReplayerBuilder: mockReplayer}
+
+		st, err := p.StateByEpoch(ctx, 0)
+		require.NoError(t, err)
+		assert.Equal(t, primitives.Slot(0), st.Slot())
+	})
+
+	t.Run("next epoch uses head state path", func(t *testing.T) {
+		// Head is at slot 30 (epoch 0), requesting epoch 1 (next)
+		// Current slot is 30 (epoch 0), so epoch 1 is next epoch
+		headSlot := primitives.Slot(30)
+		headSt, err := statenative.InitializeFromProtoPhase0(&ethpb.BeaconState{Slot: headSlot})
+		require.NoError(t, err)
+
+		currentSlot := headSlot
+		mock := &chainMock.ChainService{State: headSt, Slot: &currentSlot}
+		p := BeaconDbStater{ChainInfoFetcher: mock, GenesisTimeFetcher: mock}
+
+		// Note: This will fail since ProcessSlotsUsingNextSlotCache requires proper setup
+		_, err = p.StateByEpoch(ctx, 1)
+		// The error is expected since we don't have a fully initialized beacon state
+		assert.NotNil(t, err)
+	})
+
+	t.Run("head state already at target slot returns immediately", func(t *testing.T) {
+		// Head is at slot 32 (epoch 1 start), requesting epoch 1
+		headSlot := slotsPerEpoch // slot 32
+		headSt, err := statenative.InitializeFromProtoPhase0(&ethpb.BeaconState{Slot: headSlot})
+		require.NoError(t, err)
+
+		currentSlot := headSlot
+		mock := &chainMock.ChainService{State: headSt, Slot: &currentSlot}
+		p := BeaconDbStater{ChainInfoFetcher: mock, GenesisTimeFetcher: mock}
+
+		st, err := p.StateByEpoch(ctx, 1)
+		require.NoError(t, err)
+		assert.Equal(t, headSlot, st.Slot())
+	})
+
+	t.Run("head state past target slot returns head state", func(t *testing.T) {
+		// Head is at slot 40, requesting epoch 1 (starts at slot 32)
+		headSlot := primitives.Slot(40)
+		headSt, err := statenative.InitializeFromProtoPhase0(&ethpb.BeaconState{Slot: headSlot})
+		require.NoError(t, err)
+
+		currentSlot := headSlot
+		mock := &chainMock.ChainService{State: headSt, Slot: &currentSlot}
+		p := BeaconDbStater{ChainInfoFetcher: mock, GenesisTimeFetcher: mock}
+
+		st, err := p.StateByEpoch(ctx, 1)
+		require.NoError(t, err)
+		// Returns head state since it's already >= epoch start
+		assert.Equal(t, headSlot, st.Slot())
+	})
+}

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

@@ -52,24 +52,27 @@ func (vs *Server) ProposeAttestation(ctx context.Context, att *ethpb.Attestation
 	ctx, span := trace.StartSpan(ctx, "AttesterServer.ProposeAttestation")
 	defer span.End()
 
+	if vs.SyncChecker.Syncing() {
+		return nil, status.Errorf(codes.Unavailable, "Syncing to latest head, not ready to respond")
+	}
+
 	resp, err := vs.proposeAtt(ctx, att, att.GetData().CommitteeIndex)
 	if err != nil {
 		return nil, err
 	}
 
-	if features.Get().EnableExperimentalAttestationPool {
-		if err = vs.AttestationCache.Add(att); err != nil {
-			log.WithError(err).Error("Could not save attestation")
-		}
-	} else {
-		go func() {
+	go func() {
+		if features.Get().EnableExperimentalAttestationPool {
+			if err := vs.AttestationCache.Add(att); err != nil {
+				log.WithError(err).Error("Could not save attestation")
+			}
+		} else {
 			attCopy := att.Copy()
 			if err := vs.AttPool.SaveUnaggregatedAttestation(attCopy); err != nil {
 				log.WithError(err).Error("Could not save unaggregated attestation")
-				return
 			}
-		}()
-	}
+		}
+	}()
 
 	return resp, nil
 }
@@ -82,6 +85,10 @@ func (vs *Server) ProposeAttestationElectra(ctx context.Context, singleAtt *ethp
 	ctx, span := trace.StartSpan(ctx, "AttesterServer.ProposeAttestationElectra")
 	defer span.End()
 
+	if vs.SyncChecker.Syncing() {
+		return nil, status.Errorf(codes.Unavailable, "Syncing to latest head, not ready to respond")
+	}
+
 	resp, err := vs.proposeAtt(ctx, singleAtt, singleAtt.GetCommitteeIndex())
 	if err != nil {
 		return nil, err
@@ -98,18 +105,17 @@ func (vs *Server) ProposeAttestationElectra(ctx context.Context, singleAtt *ethp
 
 	singleAttCopy := singleAtt.Copy()
 	att := singleAttCopy.ToAttestationElectra(committee)
-	if features.Get().EnableExperimentalAttestationPool {
-		if err = vs.AttestationCache.Add(att); err != nil {
-			log.WithError(err).Error("Could not save attestation")
-		}
-	} else {
-		go func() {
+	go func() {
+		if features.Get().EnableExperimentalAttestationPool {
+			if err := vs.AttestationCache.Add(att); err != nil {
+				log.WithError(err).Error("Could not save attestation")
+			}
+		} else {
 			if err := vs.AttPool.SaveUnaggregatedAttestation(att); err != nil {
 				log.WithError(err).Error("Could not save unaggregated attestation")
-				return
 			}
-		}()
-	}
+		}
+	}()
 
 	return resp, nil
 }

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

@@ -38,6 +38,7 @@ func TestProposeAttestation(t *testing.T) {
 		OperationNotifier:       (&mock.ChainService{}).OperationNotifier(),
 		TimeFetcher:             chainService,
 		AttestationStateFetcher: chainService,
+		SyncChecker:             &mockSync.Sync{IsSyncing: false},
 	}
 	head := util.NewBeaconBlock()
 	head.Block.Slot = 999
@@ -141,6 +142,7 @@ func TestProposeAttestation_IncorrectSignature(t *testing.T) {
 		P2P:               &mockp2p.MockBroadcaster{},
 		AttPool:           attestations.NewPool(),
 		OperationNotifier: (&mock.ChainService{}).OperationNotifier(),
+		SyncChecker:       &mockSync.Sync{IsSyncing: false},
 	}
 
 	req := util.HydrateAttestation(&ethpb.Attestation{})
@@ -149,6 +151,37 @@ func TestProposeAttestation_IncorrectSignature(t *testing.T) {
 	assert.ErrorContains(t, wanted, err)
 }
 
+func TestProposeAttestation_Syncing(t *testing.T) {
+	attesterServer := &Server{
+		SyncChecker: &mockSync.Sync{IsSyncing: true},
+	}
+
+	req := util.HydrateAttestation(&ethpb.Attestation{})
+	_, err := attesterServer.ProposeAttestation(t.Context(), req)
+	assert.ErrorContains(t, "Syncing to latest head", err)
+	s, ok := status.FromError(err)
+	require.Equal(t, true, ok)
+	assert.Equal(t, codes.Unavailable, s.Code())
+}
+
+func TestProposeAttestationElectra_Syncing(t *testing.T) {
+	attesterServer := &Server{
+		SyncChecker: &mockSync.Sync{IsSyncing: true},
+	}
+
+	req := &ethpb.SingleAttestation{
+		Data: &ethpb.AttestationData{
+			Source: &ethpb.Checkpoint{Root: make([]byte, 32)},
+			Target: &ethpb.Checkpoint{Root: make([]byte, 32)},
+		},
+	}
+	_, err := attesterServer.ProposeAttestationElectra(t.Context(), req)
+	assert.ErrorContains(t, "Syncing to latest head", err)
+	s, ok := status.FromError(err)
+	require.Equal(t, true, ok)
+	assert.Equal(t, codes.Unavailable, s.Code())
+}
+
 func TestGetAttestationData_OK(t *testing.T) {
 	block := util.NewBeaconBlock()
 	block.Block.Slot = 3*params.BeaconConfig().SlotsPerEpoch + 1

beacon-chain/rpc/testutil/BUILD.bazel

@@ -26,5 +26,6 @@ go_library(
         "//proto/prysm/v1alpha1:go_default_library",
         "//testing/require:go_default_library",
         "//testing/util:go_default_library",
+        "//time/slots:go_default_library",
     ],
 )

beacon-chain/rpc/testutil/mock_stater.go

@@ -6,6 +6,7 @@ import (
 	"github.com/OffchainLabs/prysm/v7/beacon-chain/state"
 	"github.com/OffchainLabs/prysm/v7/consensus-types/primitives"
 	"github.com/OffchainLabs/prysm/v7/encoding/bytesutil"
+	"github.com/OffchainLabs/prysm/v7/time/slots"
 )
 
 // MockStater is a fake implementation of lookup.Stater.
@@ -14,6 +15,7 @@ type MockStater struct {
 	StateProviderFunc func(ctx context.Context, stateId []byte) (state.BeaconState, error)
 	BeaconStateRoot   []byte
 	StatesBySlot      map[primitives.Slot]state.BeaconState
+	StatesByEpoch     map[primitives.Epoch]state.BeaconState
 	StatesByRoot      map[[32]byte]state.BeaconState
 	CustomError       error
 }
@@ -43,3 +45,22 @@ func (m *MockStater) StateRoot(context.Context, []byte) ([]byte, error) {
 func (m *MockStater) StateBySlot(_ context.Context, s primitives.Slot) (state.BeaconState, error) {
 	return m.StatesBySlot[s], nil
 }
+
+// StateByEpoch --
+func (m *MockStater) StateByEpoch(_ context.Context, e primitives.Epoch) (state.BeaconState, error) {
+	if m.CustomError != nil {
+		return nil, m.CustomError
+	}
+	if m.StatesByEpoch != nil {
+		return m.StatesByEpoch[e], nil
+	}
+	// Fall back to StatesBySlot if StatesByEpoch is not set
+	slot, err := slots.EpochStart(e)
+	if err != nil {
+		return nil, err
+	}
+	if m.StatesBySlot != nil {
+		return m.StatesBySlot[slot], nil
+	}
+	return m.BeaconState, nil
+}

beacon-chain/state/stategen/BUILD.bazel

@@ -29,6 +29,7 @@ go_library(
         "//beacon-chain/state:go_default_library",
         "//beacon-chain/sync/backfill/coverage:go_default_library",
         "//cache/lru:go_default_library",
+        "//config/features:go_default_library",
         "//config/params:go_default_library",
         "//consensus-types/blocks:go_default_library",
         "//consensus-types/interfaces:go_default_library",
@@ -68,11 +69,14 @@ go_test(
         "//beacon-chain/core/helpers:go_default_library",
         "//beacon-chain/core/transition:go_default_library",
         "//beacon-chain/db:go_default_library",
+        "//beacon-chain/db/kv:go_default_library",
         "//beacon-chain/db/testing:go_default_library",
         "//beacon-chain/forkchoice/doubly-linked-tree:go_default_library",
         "//beacon-chain/state:go_default_library",
         "//beacon-chain/state/state-native:go_default_library",
         "//beacon-chain/state/testing:go_default_library",
+        "//cmd/beacon-chain/flags:go_default_library",
+        "//config/features:go_default_library",
         "//config/params:go_default_library",
         "//consensus-types/blocks:go_default_library",
         "//consensus-types/blocks/testing:go_default_library",

beacon-chain/state/stategen/migrate.go

@@ -5,9 +5,13 @@ import (
 	"encoding/hex"
 	"fmt"
 
+	"github.com/OffchainLabs/prysm/v7/beacon-chain/core/transition"
 	"github.com/OffchainLabs/prysm/v7/beacon-chain/state"
+	"github.com/OffchainLabs/prysm/v7/config/features"
+	"github.com/OffchainLabs/prysm/v7/consensus-types/primitives"
 	"github.com/OffchainLabs/prysm/v7/encoding/bytesutil"
 	"github.com/OffchainLabs/prysm/v7/monitoring/tracing/trace"
+	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
 )
 
@@ -24,6 +28,10 @@ func (s *State) MigrateToCold(ctx context.Context, fRoot [32]byte) error {
 	s.migrationLock.Lock()
 	defer s.migrationLock.Unlock()
 
+	if features.Get().EnableStateDiff {
+		return s.migrateToColdHdiff(ctx, fRoot)
+	}
+
 	s.finalizedInfo.lock.RLock()
 	oldFSlot := s.finalizedInfo.slot
 	s.finalizedInfo.lock.RUnlock()
@@ -37,76 +45,71 @@ func (s *State) MigrateToCold(ctx context.Context, fRoot [32]byte) error {
 		return nil
 	}
 
-	// Start at previous finalized slot, stop at current finalized slot (it will be handled in the next migration).
-	// If the slot is on archived point, save the state of that slot to the DB.
-	for slot := oldFSlot; slot < fSlot; slot++ {
+	// Calculate the first archived point slot >= oldFSlot (but > 0).
+	// This avoids iterating through every slot and only visits archived points directly.
+	var startSlot primitives.Slot
+	if oldFSlot == 0 {
+		startSlot = s.slotsPerArchivedPoint
+	} else {
+		// Round up to the next archived point
+		startSlot = (oldFSlot + s.slotsPerArchivedPoint - 1) / s.slotsPerArchivedPoint * s.slotsPerArchivedPoint
+	}
+
+	// Start at the first archived point after old finalized slot, stop before current finalized slot.
+	// Jump directly between archived points.
+	for slot := startSlot; slot < fSlot; slot += s.slotsPerArchivedPoint {
 		if ctx.Err() != nil {
 			return ctx.Err()
 		}
 
-		if slot%s.slotsPerArchivedPoint == 0 && slot != 0 {
-			cached, exists, err := s.epochBoundaryStateCache.getBySlot(slot)
+		cached, exists, err := s.epochBoundaryStateCache.getBySlot(slot)
+		if err != nil {
+			return fmt.Errorf("could not get epoch boundary state for slot %d", slot)
+		}
+
+		var aRoot [32]byte
+		var aState state.BeaconState
+
+		// When the epoch boundary state is not in cache due to skip slot scenario,
+		// we have to regenerate the state which will represent epoch boundary.
+		// By finding the highest available block below epoch boundary slot, we
+		// generate the state for that block root.
+		if exists {
+			aRoot = cached.root
+			aState = cached.state
+		} else {
+			_, roots, err := s.beaconDB.HighestRootsBelowSlot(ctx, slot)
 			if err != nil {
-				return fmt.Errorf("could not get epoch boundary state for slot %d", slot)
+				return err
 			}
-
-			var aRoot [32]byte
-			var aState state.BeaconState
-
-			// When the epoch boundary state is not in cache due to skip slot scenario,
-			// we have to regenerate the state which will represent epoch boundary.
-			// By finding the highest available block below epoch boundary slot, we
-			// generate the state for that block root.
-			if exists {
-				aRoot = cached.root
-				aState = cached.state
-			} else {
-				_, roots, err := s.beaconDB.HighestRootsBelowSlot(ctx, slot)
+			// Given the block has been finalized, the db should not have more than one block in a given slot.
+			// We should error out when this happens.
+			if len(roots) != 1 {
+				return errUnknownBlock
+			}
+			aRoot = roots[0]
+			// There's no need to generate the state if the state already exists in the DB.
+			// We can skip saving the state.
+			if !s.beaconDB.HasState(ctx, aRoot) {
+				aState, err = s.StateByRoot(ctx, aRoot)
 				if err != nil {
 					return err
 				}
-				// Given the block has been finalized, the db should not have more than one block in a given slot.
-				// We should error out when this happens.
-				if len(roots) != 1 {
-					return errUnknownBlock
-				}
-				aRoot = roots[0]
-				// There's no need to generate the state if the state already exists in the DB.
-				// We can skip saving the state.
-				if !s.beaconDB.HasState(ctx, aRoot) {
-					aState, err = s.StateByRoot(ctx, aRoot)
-					if err != nil {
-						return err
-					}
-				}
 			}
-
-			if s.beaconDB.HasState(ctx, aRoot) {
-				// If you are migrating a state and its already part of the hot state cache saved to the db,
-				// you can just remove it from the hot state cache as it becomes redundant.
-				s.saveHotStateDB.lock.Lock()
-				roots := s.saveHotStateDB.blockRootsOfSavedStates
-				for i := range roots {
-					if aRoot == roots[i] {
-						s.saveHotStateDB.blockRootsOfSavedStates = append(roots[:i], roots[i+1:]...)
-						// There shouldn't be duplicated roots in `blockRootsOfSavedStates`.
-						// Break here is ok.
-						break
-					}
-				}
-				s.saveHotStateDB.lock.Unlock()
-				continue
-			}
-
-			if err := s.beaconDB.SaveState(ctx, aState, aRoot); err != nil {
-				return err
-			}
-			log.WithFields(
-				logrus.Fields{
-					"slot": aState.Slot(),
-					"root": hex.EncodeToString(bytesutil.Trunc(aRoot[:])),
-				}).Info("Saved state in DB")
 		}
+		if s.beaconDB.HasState(ctx, aRoot) {
+			s.migrateHotToCold(aRoot)
+			continue
+		}
+
+		if err := s.beaconDB.SaveState(ctx, aState, aRoot); err != nil {
+			return err
+		}
+		log.WithFields(
+			logrus.Fields{
+				"slot": aState.Slot(),
+				"root": hex.EncodeToString(bytesutil.Trunc(aRoot[:])),
+			}).Info("Saved state in DB")
 	}
 
 	// Update finalized info in memory.
@@ -120,3 +123,103 @@ func (s *State) MigrateToCold(ctx context.Context, fRoot [32]byte) error {
 
 	return nil
 }
+
+// migrateToColdHdiff saves the state-diffs for slots that are in the state diff tree after finalization
+func (s *State) migrateToColdHdiff(ctx context.Context, fRoot [32]byte) error {
+	s.finalizedInfo.lock.RLock()
+	oldFSlot := s.finalizedInfo.slot
+	s.finalizedInfo.lock.RUnlock()
+	fSlot, err := s.beaconDB.SlotByBlockRoot(ctx, fRoot)
+	if err != nil {
+		return errors.Wrap(err, "could not get slot by block root")
+	}
+	for slot := oldFSlot; slot < fSlot; slot++ {
+		if ctx.Err() != nil {
+			return ctx.Err()
+		}
+		_, lvl, err := s.beaconDB.SlotInDiffTree(slot)
+		if err != nil {
+			log.WithError(err).Errorf("could not determine if slot %d is in diff tree", slot)
+			continue
+		}
+		if lvl == -1 {
+			continue
+		}
+		// The state needs to be saved.
+		// Try the epoch boundary cache first.
+		cached, exists, err := s.epochBoundaryStateCache.getBySlot(slot)
+		if err != nil {
+			log.WithError(err).Errorf("could not get epoch boundary state for slot %d", slot)
+			cached = nil
+			exists = false
+		}
+		var aRoot [32]byte
+		var aState state.BeaconState
+		if exists {
+			aRoot = cached.root
+			aState = cached.state
+		} else {
+			_, roots, err := s.beaconDB.HighestRootsBelowSlot(ctx, slot)
+			if err != nil {
+				return err
+			}
+			// Given the block has been finalized, the db should not have more than one block in a given slot.
+			// We should error out when this happens.
+			if len(roots) != 1 {
+				return errUnknownBlock
+			}
+			aRoot = roots[0]
+			// Different than the legacy MigrateToCold, we need to always get the state even if
+			// the state exists in DB as part of the hot state db, because we need to process slots
+			// to the state diff tree slots.
+			aState, err = s.StateByRoot(ctx, aRoot)
+			if err != nil {
+				return err
+			}
+		}
+		if s.beaconDB.HasState(ctx, aRoot) {
+			s.migrateHotToCold(aRoot)
+			continue
+		}
+		// advance slots to the target slot
+		if aState.Slot() < slot {
+			aState, err = transition.ProcessSlots(ctx, aState, slot)
+			if err != nil {
+				return errors.Wrapf(err, "could not process slots to slot %d", slot)
+			}
+		}
+		if err := s.beaconDB.SaveState(ctx, aState, aRoot); err != nil {
+			return err
+		}
+		log.WithFields(
+			logrus.Fields{
+				"slot": aState.Slot(),
+				"root": fmt.Sprintf("%#x", aRoot),
+			}).Info("Saved state in DB")
+	}
+	// Update finalized info in memory.
+	fInfo, ok, err := s.epochBoundaryStateCache.getByBlockRoot(fRoot)
+	if err != nil {
+		return err
+	}
+	if ok {
+		s.SaveFinalizedState(fSlot, fRoot, fInfo.state)
+	}
+	return nil
+}
+
+func (s *State) migrateHotToCold(aRoot [32]byte) {
+	// If you are migrating a state and its already part of the hot state cache saved to the db,
+	// you can just remove it from the hot state cache as it becomes redundant.
+	s.saveHotStateDB.lock.Lock()
+	roots := s.saveHotStateDB.blockRootsOfSavedStates
+	for i := range roots {
+		if aRoot == roots[i] {
+			s.saveHotStateDB.blockRootsOfSavedStates = append(roots[:i], roots[i+1:]...)
+			// There shouldn't be duplicated roots in `blockRootsOfSavedStates`.
+			// Break here is ok.
+			break
+		}
+	}
+	s.saveHotStateDB.lock.Unlock()
+}

beacon-chain/state/stategen/migrate_test.go

@@ -4,8 +4,11 @@ import (
 	"testing"
 
 	"github.com/OffchainLabs/prysm/v7/beacon-chain/core/blocks"
+	"github.com/OffchainLabs/prysm/v7/beacon-chain/db/kv"
 	testDB "github.com/OffchainLabs/prysm/v7/beacon-chain/db/testing"
 	doublylinkedtree "github.com/OffchainLabs/prysm/v7/beacon-chain/forkchoice/doubly-linked-tree"
+	"github.com/OffchainLabs/prysm/v7/cmd/beacon-chain/flags"
+	"github.com/OffchainLabs/prysm/v7/config/features"
 	consensusblocks "github.com/OffchainLabs/prysm/v7/consensus-types/blocks"
 	"github.com/OffchainLabs/prysm/v7/consensus-types/primitives"
 	ethpb "github.com/OffchainLabs/prysm/v7/proto/prysm/v1alpha1"
@@ -224,3 +227,170 @@ func TestMigrateToCold_ParallelCalls(t *testing.T) {
 	assert.DeepEqual(t, [][32]byte{r7}, service.saveHotStateDB.blockRootsOfSavedStates, "Did not remove all saved hot state roots")
 	require.LogsContain(t, hook, "Saved state in DB")
 }
+
+// =========================================================================
+// Tests for migrateToColdHdiff (state diff migration)
+// =========================================================================
+
+// setStateDiffExponents sets state diff exponents for testing.
+// Uses exponents [6, 5] which means:
+// - Level 0: Every 2^6 = 64 slots (full snapshot)
+// - Level 1: Every 2^5 = 32 slots (diff)
+func setStateDiffExponents() {
+	globalFlags := flags.GlobalFlags{
+		StateDiffExponents: []int{6, 5},
+	}
+	flags.Init(&globalFlags)
+}
+
+// TestMigrateToColdHdiff_CanUpdateFinalizedInfo verifies that the migration
+// correctly updates finalized info when migrating to slots not in the diff tree.
+func TestMigrateToColdHdiff_CanUpdateFinalizedInfo(t *testing.T) {
+	ctx := t.Context()
+	// Set exponents and create DB first (without EnableStateDiff flag).
+	setStateDiffExponents()
+	beaconDB := testDB.SetupDB(t)
+	// Initialize the state diff cache via the method on *kv.Store (not in interface).
+	require.NoError(t, beaconDB.(*kv.Store).InitStateDiffCacheForTesting(t, 0))
+	// Now enable the feature flag.
+	resetCfg := features.InitWithReset(&features.Flags{EnableStateDiff: true})
+	defer resetCfg()
+	service := New(beaconDB, doublylinkedtree.New())
+
+	beaconState, _ := util.DeterministicGenesisState(t, 32)
+	genesisStateRoot, err := beaconState.HashTreeRoot(ctx)
+	require.NoError(t, err)
+	genesis := blocks.NewGenesisBlock(genesisStateRoot[:])
+	util.SaveBlock(t, ctx, beaconDB, genesis)
+	gRoot, err := genesis.Block.HashTreeRoot()
+	require.NoError(t, err)
+	require.NoError(t, beaconDB.SaveGenesisBlockRoot(ctx, gRoot))
+
+	// Put genesis state in epoch boundary cache so migrateToColdHdiff doesn't need to retrieve from DB.
+	require.NoError(t, service.epochBoundaryStateCache.put(gRoot, beaconState))
+
+	// Set initial finalized info at genesis.
+	service.finalizedInfo = &finalizedInfo{
+		slot:  0,
+		root:  gRoot,
+		state: beaconState,
+	}
+
+	// Create finalized block at slot 10 (not in diff tree, so no intermediate states saved).
+	finalizedState := beaconState.Copy()
+	require.NoError(t, finalizedState.SetSlot(10))
+	b := util.NewBeaconBlock()
+	b.Block.Slot = 10
+	fRoot, err := b.Block.HashTreeRoot()
+	require.NoError(t, err)
+	util.SaveBlock(t, ctx, beaconDB, b)
+	require.NoError(t, service.epochBoundaryStateCache.put(fRoot, finalizedState))
+
+	require.NoError(t, service.MigrateToCold(ctx, fRoot))
+
+	// Verify finalized info is updated.
+	assert.Equal(t, primitives.Slot(10), service.finalizedInfo.slot)
+	assert.DeepEqual(t, fRoot, service.finalizedInfo.root)
+	expectedHTR, err := finalizedState.HashTreeRoot(ctx)
+	require.NoError(t, err)
+	actualHTR, err := service.finalizedInfo.state.HashTreeRoot(ctx)
+	require.NoError(t, err)
+	assert.DeepEqual(t, expectedHTR, actualHTR)
+}
+
+// TestMigrateToColdHdiff_SkipsSlotsNotInDiffTree verifies that the migration
+// skips slots that are not in the diff tree.
+func TestMigrateToColdHdiff_SkipsSlotsNotInDiffTree(t *testing.T) {
+	hook := logTest.NewGlobal()
+	ctx := t.Context()
+	// Set exponents and create DB first (without EnableStateDiff flag).
+	setStateDiffExponents()
+	beaconDB := testDB.SetupDB(t)
+	// Initialize the state diff cache via the method on *kv.Store (not in interface).
+	require.NoError(t, beaconDB.(*kv.Store).InitStateDiffCacheForTesting(t, 0))
+	// Now enable the feature flag.
+	resetCfg := features.InitWithReset(&features.Flags{EnableStateDiff: true})
+	defer resetCfg()
+	service := New(beaconDB, doublylinkedtree.New())
+
+	beaconState, pks := util.DeterministicGenesisState(t, 32)
+	genesisStateRoot, err := beaconState.HashTreeRoot(ctx)
+	require.NoError(t, err)
+	genesis := blocks.NewGenesisBlock(genesisStateRoot[:])
+	util.SaveBlock(t, ctx, beaconDB, genesis)
+	gRoot, err := genesis.Block.HashTreeRoot()
+	require.NoError(t, err)
+	require.NoError(t, beaconDB.SaveGenesisBlockRoot(ctx, gRoot))
+
+	// Start from slot 1 to avoid slot 0 which is in the diff tree.
+	service.finalizedInfo = &finalizedInfo{
+		slot:  1,
+		root:  gRoot,
+		state: beaconState,
+	}
+
+	// Reset the log hook to ignore setup logs.
+	hook.Reset()
+
+	// Create a block at slot 20 (NOT in diff tree with exponents [6,5]).
+	b20, err := util.GenerateFullBlock(beaconState, pks, util.DefaultBlockGenConfig(), 20)
+	require.NoError(t, err)
+	r20, err := b20.Block.HashTreeRoot()
+	require.NoError(t, err)
+	util.SaveBlock(t, ctx, beaconDB, b20)
+	require.NoError(t, beaconDB.SaveStateSummary(ctx, &ethpb.StateSummary{Slot: 20, Root: r20[:]}))
+
+	// Put finalized state in cache.
+	finalizedState := beaconState.Copy()
+	require.NoError(t, finalizedState.SetSlot(20))
+	require.NoError(t, service.epochBoundaryStateCache.put(r20, finalizedState))
+
+	require.NoError(t, service.MigrateToCold(ctx, r20))
+
+	// Verify NO states were saved during migration (slots 1-19 are not in diff tree).
+	assert.LogsDoNotContain(t, hook, "Saved state in DB")
+}
+
+// TestMigrateToColdHdiff_NoOpWhenFinalizedSlotNotAdvanced verifies that
+// migration is a no-op when the finalized slot has not advanced.
+func TestMigrateToColdHdiff_NoOpWhenFinalizedSlotNotAdvanced(t *testing.T) {
+	ctx := t.Context()
+	// Set exponents and create DB first (without EnableStateDiff flag).
+	setStateDiffExponents()
+	beaconDB := testDB.SetupDB(t)
+	// Initialize the state diff cache via the method on *kv.Store (not in interface).
+	require.NoError(t, beaconDB.(*kv.Store).InitStateDiffCacheForTesting(t, 0))
+	// Now enable the feature flag.
+	resetCfg := features.InitWithReset(&features.Flags{EnableStateDiff: true})
+	defer resetCfg()
+	service := New(beaconDB, doublylinkedtree.New())
+
+	beaconState, _ := util.DeterministicGenesisState(t, 32)
+	genesisStateRoot, err := beaconState.HashTreeRoot(ctx)
+	require.NoError(t, err)
+	genesis := blocks.NewGenesisBlock(genesisStateRoot[:])
+	util.SaveBlock(t, ctx, beaconDB, genesis)
+	gRoot, err := genesis.Block.HashTreeRoot()
+	require.NoError(t, err)
+	require.NoError(t, beaconDB.SaveGenesisBlockRoot(ctx, gRoot))
+
+	// Set finalized info already at slot 50.
+	finalizedState := beaconState.Copy()
+	require.NoError(t, finalizedState.SetSlot(50))
+	service.finalizedInfo = &finalizedInfo{
+		slot:  50,
+		root:  gRoot,
+		state: finalizedState,
+	}
+
+	// Create block at same slot 50.
+	b := util.NewBeaconBlock()
+	b.Block.Slot = 50
+	fRoot, err := b.Block.HashTreeRoot()
+	require.NoError(t, err)
+	util.SaveBlock(t, ctx, beaconDB, b)
+	require.NoError(t, service.epochBoundaryStateCache.put(fRoot, finalizedState))
+
+	// Migration should be a no-op (finalized slot not advancing).
+	require.NoError(t, service.MigrateToCold(ctx, fRoot))
+}

beacon-chain/sync/batch_verifier.go

@@ -161,13 +161,17 @@ func (s *Service) validateWithKzgBatchVerifier(ctx context.Context, dataColumns
 
 	timeout := time.Duration(params.BeaconConfig().SecondsPerSlot) * time.Second
 
-	resChan := make(chan error)
+	resChan := make(chan error, 1)
 	verificationSet := &kzgVerifier{dataColumns: dataColumns, resChan: resChan}
-	s.kzgChan <- verificationSet
-
 	ctx, cancel := context.WithTimeout(ctx, timeout)
 	defer cancel()
 
+	select {
+	case s.kzgChan <- verificationSet:
+	case <-ctx.Done():
+		return pubsub.ValidationIgnore, ctx.Err()
+	}
+
 	select {
 	case <-ctx.Done():
 		return pubsub.ValidationIgnore, ctx.Err() // parent context canceled, give up

beacon-chain/sync/data_column_sidecars.go

@@ -3,6 +3,7 @@ package sync
 import (
 	"bytes"
 	"context"
+	"fmt"
 	"maps"
 	"slices"
 	"sync"
@@ -243,8 +244,10 @@ func requestDirectSidecarsFromPeers(
 	}
 
 	// Compute missing indices by root, excluding those already in storage.
+	var lastRoot [fieldparams.RootLength]byte
 	missingIndicesByRoot := make(map[[fieldparams.RootLength]byte]map[uint64]bool, len(incompleteRoots))
 	for root := range incompleteRoots {
+		lastRoot = root
 		storedIndices := storedIndicesByRoot[root]
 
 		missingIndices := make(map[uint64]bool, len(requestedIndices))
@@ -259,6 +262,7 @@ func requestDirectSidecarsFromPeers(
 		}
 	}
 
+	initialMissingRootCount := len(missingIndicesByRoot)
 	initialMissingCount := computeTotalCount(missingIndicesByRoot)
 
 	indicesByRootByPeer, err := computeIndicesByRootByPeer(params.P2P, slotByRoot, missingIndicesByRoot, connectedPeers)
@@ -301,11 +305,19 @@ func requestDirectSidecarsFromPeers(
 		}
 	}
 
-	log.WithFields(logrus.Fields{
-		"duration":            time.Since(start),
-		"initialMissingCount": initialMissingCount,
-		"finalMissingCount":   computeTotalCount(missingIndicesByRoot),
-	}).Debug("Requested direct data column sidecars from peers")
+	log := log.WithFields(logrus.Fields{
+		"duration":                time.Since(start),
+		"initialMissingRootCount": initialMissingRootCount,
+		"initialMissingCount":     initialMissingCount,
+		"finalMissingRootCount":   len(missingIndicesByRoot),
+		"finalMissingCount":       computeTotalCount(missingIndicesByRoot),
+	})
+
+	if initialMissingRootCount == 1 {
+		log = log.WithField("root", fmt.Sprintf("%#x", lastRoot))
+	}
+
+	log.Debug("Requested direct data column sidecars from peers")
 
 	return verifiedColumnsByRoot, nil
 }

beacon-chain/sync/kzg_batch_verifier_test.go

@@ -7,6 +7,7 @@ import (
 	"time"
 
 	"github.com/OffchainLabs/prysm/v7/beacon-chain/blockchain/kzg"
+	"github.com/OffchainLabs/prysm/v7/config/params"
 	"github.com/OffchainLabs/prysm/v7/consensus-types/blocks"
 	ethpb "github.com/OffchainLabs/prysm/v7/proto/prysm/v1alpha1"
 	"github.com/OffchainLabs/prysm/v7/testing/assert"
@@ -268,6 +269,71 @@ func TestKzgBatchVerifierFallback(t *testing.T) {
 	})
 }
 
+func TestValidateWithKzgBatchVerifier_DeadlockOnTimeout(t *testing.T) {
+	err := kzg.Start()
+	require.NoError(t, err)
+
+	params.SetupTestConfigCleanup(t)
+	cfg := params.BeaconConfig().Copy()
+	cfg.SecondsPerSlot = 0
+	params.OverrideBeaconConfig(cfg)
+
+	ctx, cancel := context.WithCancel(t.Context())
+	defer cancel()
+
+	service := &Service{
+		ctx:     ctx,
+		kzgChan: make(chan *kzgVerifier),
+	}
+	go service.kzgVerifierRoutine()
+
+	result, err := service.validateWithKzgBatchVerifier(context.Background(), nil)
+	require.Equal(t, pubsub.ValidationIgnore, result)
+	require.ErrorIs(t, err, context.DeadlineExceeded)
+
+	done := make(chan struct{})
+	go func() {
+		_, _ = service.validateWithKzgBatchVerifier(context.Background(), nil)
+		close(done)
+	}()
+
+	select {
+	case <-done:
+	case <-time.After(500 * time.Millisecond):
+		t.Fatal("validateWithKzgBatchVerifier blocked")
+	}
+}
+
+func TestValidateWithKzgBatchVerifier_ContextCanceledBeforeSend(t *testing.T) {
+	cancelledCtx, cancel := context.WithCancel(t.Context())
+	cancel()
+
+	service := &Service{
+		ctx:     context.Background(),
+		kzgChan: make(chan *kzgVerifier),
+	}
+
+	done := make(chan struct{})
+	go func() {
+		result, err := service.validateWithKzgBatchVerifier(cancelledCtx, nil)
+		require.Equal(t, pubsub.ValidationIgnore, result)
+		require.ErrorIs(t, err, context.Canceled)
+		close(done)
+	}()
+
+	select {
+	case <-done:
+	case <-time.After(500 * time.Millisecond):
+		t.Fatal("validateWithKzgBatchVerifier did not return after context cancellation")
+	}
+
+	select {
+	case <-service.kzgChan:
+		t.Fatal("verificationSet was sent to kzgChan despite canceled context")
+	default:
+	}
+}
+
 func createValidTestDataColumns(t *testing.T, count int) []blocks.RODataColumn {
 	_, roSidecars, _ := util.GenerateTestFuluBlockWithSidecars(t, count)
 	if len(roSidecars) >= count {

beacon-chain/sync/metrics.go

@@ -204,6 +204,13 @@ var (
 		},
 	)
 
+	dataColumnsRecoveredFromELAttempts = promauto.NewCounter(
+		prometheus.CounterOpts{
+			Name: "data_columns_recovered_from_el_attempts",
+			Help: "Count the number of data columns recovery attempts from the execution layer.",
+		},
+	)
+
 	dataColumnsRecoveredFromELTotal = promauto.NewCounter(
 		prometheus.CounterOpts{
 			Name: "data_columns_recovered_from_el_total",
@@ -242,6 +249,13 @@ var (
 			Buckets: []float64{100, 250, 500, 750, 1000, 1500, 2000, 4000, 8000, 12000, 16000},
 		},
 	)
+
+	dataColumnSidecarsObtainedViaELCount = promauto.NewSummary(
+		prometheus.SummaryOpts{
+			Name: "data_column_obtained_via_el_count",
+			Help: "Count the number of data column sidecars obtained via the execution layer.",
+		},
+	)
 )
 
 func (s *Service) updateMetrics() {

beacon-chain/sync/pending_attestations_queue.go

@@ -3,9 +3,9 @@ package sync
 import (
 	"bytes"
 	"context"
-	"encoding/hex"
 	"fmt"
 	"slices"
+	"time"
 
 	"github.com/OffchainLabs/prysm/v7/beacon-chain/blockchain"
 	"github.com/OffchainLabs/prysm/v7/beacon-chain/core/blocks"
@@ -21,13 +21,23 @@ import (
 	"github.com/OffchainLabs/prysm/v7/monitoring/tracing/trace"
 	ethpb "github.com/OffchainLabs/prysm/v7/proto/prysm/v1alpha1"
 	"github.com/OffchainLabs/prysm/v7/runtime/version"
-	"github.com/OffchainLabs/prysm/v7/time"
 	"github.com/OffchainLabs/prysm/v7/time/slots"
 	pubsub "github.com/libp2p/go-libp2p-pubsub"
+	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
 )
 
-var pendingAttsLimit = 32768
+const pendingAttsLimit = 32768
+
+// aggregatorIndexFilter defines how aggregator index should be handled in equality checks.
+type aggregatorIndexFilter int
+
+const (
+	// ignoreAggregatorIndex means aggregates differing only by aggregator index are considered equal.
+	ignoreAggregatorIndex aggregatorIndexFilter = iota
+	// includeAggregatorIndex means aggregator index must also match for aggregates to be considered equal.
+	includeAggregatorIndex
+)
 
 // This method processes pending attestations as a "known" block as arrived. With validations,
 // the valid attestations get saved into the operation mem pool, and the invalid attestations gets deleted
@@ -50,16 +60,7 @@ func (s *Service) processPendingAttsForBlock(ctx context.Context, bRoot [32]byte
 	attestations := s.blkRootToPendingAtts[bRoot]
 	s.pendingAttsLock.RUnlock()
 
-	if len(attestations) > 0 {
-		start := time.Now()
-		s.processAttestations(ctx, attestations)
-		duration := time.Since(start)
-		log.WithFields(logrus.Fields{
-			"blockRoot":        hex.EncodeToString(bytesutil.Trunc(bRoot[:])),
-			"pendingAttsCount": len(attestations),
-			"duration":         duration,
-		}).Debug("Verified and saved pending attestations to pool")
-	}
+	s.processAttestations(ctx, attestations)
 
 	randGen := rand.NewGenerator()
 	// Delete the missing block root key from pending attestation queue so a node will not request for the block again.
@@ -79,26 +80,71 @@ func (s *Service) processPendingAttsForBlock(ctx context.Context, bRoot [32]byte
 	return s.sendBatchRootRequest(ctx, pendingRoots, randGen)
 }
 
+// processAttestations processes a list of attestations.
+// It assumes (for logging purposes only) that all attestations pertain to the same block.
 func (s *Service) processAttestations(ctx context.Context, attestations []any) {
 	if len(attestations) == 0 {
 		return
 	}
 
+	firstAttestation := attestations[0]
+	var blockRoot []byte
+	switch v := firstAttestation.(type) {
+	case ethpb.Att:
+		blockRoot = v.GetData().BeaconBlockRoot
+	case ethpb.SignedAggregateAttAndProof:
+		blockRoot = v.AggregateAttestationAndProof().AggregateVal().GetData().BeaconBlockRoot
+	default:
+		log.Warnf("Unexpected attestation type %T, skipping processing", v)
+		return
+	}
+
+	validAggregates := make([]ethpb.SignedAggregateAttAndProof, 0, len(attestations))
+	startAggregate := time.Now()
 	atts := make([]ethpb.Att, 0, len(attestations))
+	aggregateAttAndProofCount := 0
 	for _, att := range attestations {
 		switch v := att.(type) {
 		case ethpb.Att:
 			atts = append(atts, v)
 		case ethpb.SignedAggregateAttAndProof:
-			s.processAggregate(ctx, v)
+			aggregateAttAndProofCount++
+			// Avoid processing multiple aggregates only differing by aggregator index.
+			if slices.ContainsFunc(validAggregates, func(other ethpb.SignedAggregateAttAndProof) bool {
+				return pendingAggregatesAreEqual(v, other, ignoreAggregatorIndex)
+			}) {
+				continue
+			}
+
+			if err := s.processAggregate(ctx, v); err != nil {
+				log.WithError(err).Debug("Pending aggregate attestation could not be processed")
+				continue
+			}
+
+			validAggregates = append(validAggregates, v)
 		default:
 			log.Warnf("Unexpected attestation type %T, skipping", v)
 		}
 	}
+	durationAggregateAttAndProof := time.Since(startAggregate)
 
+	startAtts := time.Now()
 	for _, bucket := range bucketAttestationsByData(atts) {
 		s.processAttestationBucket(ctx, bucket)
 	}
+
+	durationAtts := time.Since(startAtts)
+
+	log.WithFields(logrus.Fields{
+		"blockRoot":                       fmt.Sprintf("%#x", blockRoot),
+		"totalCount":                      len(attestations),
+		"aggregateAttAndProofCount":       aggregateAttAndProofCount,
+		"uniqueAggregateAttAndProofCount": len(validAggregates),
+		"attCount":                        len(atts),
+		"durationTotal":                   durationAggregateAttAndProof + durationAtts,
+		"durationAggregateAttAndProof":    durationAggregateAttAndProof,
+		"durationAtts":                    durationAtts,
+	}).Debug("Verified and saved pending attestations to pool")
 }
 
 // attestationBucket groups attestations with the same AttestationData for batch processing.
@@ -265,7 +311,7 @@ func (s *Service) processVerifiedAttestation(
 	if key, err := generateUnaggregatedAttCacheKey(broadcastAtt); err != nil {
 		log.WithError(err).Error("Failed to generate cache key for attestation tracking")
 	} else {
-		s.setSeenUnaggregatedAtt(key)
+		_ = s.setSeenUnaggregatedAtt(key)
 	}
 
 	valCount, err := helpers.ActiveValidatorCount(ctx, preState, slots.ToEpoch(data.Slot))
@@ -303,28 +349,29 @@ func (s *Service) processVerifiedAttestation(
 	})
 }
 
-func (s *Service) processAggregate(ctx context.Context, aggregate ethpb.SignedAggregateAttAndProof) {
+func (s *Service) processAggregate(ctx context.Context, aggregate ethpb.SignedAggregateAttAndProof) error {
 	res, err := s.validateAggregatedAtt(ctx, aggregate)
 	if err != nil {
 		log.WithError(err).Debug("Pending aggregated attestation failed validation")
-		return
+		return errors.Wrap(err, "validate aggregated att")
 	}
+
 	if res != pubsub.ValidationAccept || !s.validateBlockInAttestation(ctx, aggregate) {
-		log.Debug("Pending aggregated attestation failed validation")
-		return
+		return errors.New("Pending aggregated attestation failed validation")
 	}
 
 	att := aggregate.AggregateAttestationAndProof().AggregateVal()
 	if err := s.saveAttestation(att); err != nil {
-		log.WithError(err).Debug("Could not save aggregated attestation")
-		return
+		return errors.Wrap(err, "save attestation")
 	}
 
-	s.setAggregatorIndexEpochSeen(att.GetData().Target.Epoch, aggregate.AggregateAttestationAndProof().GetAggregatorIndex())
+	_ = s.setAggregatorIndexEpochSeen(att.GetData().Target.Epoch, aggregate.AggregateAttestationAndProof().GetAggregatorIndex())
 
 	if err := s.cfg.p2p.Broadcast(ctx, aggregate); err != nil {
 		log.WithError(err).Debug("Could not broadcast aggregated attestation")
 	}
+
+	return nil
 }
 
 // This defines how pending aggregates are saved in the map. The key is the
@@ -336,7 +383,7 @@ func (s *Service) savePendingAggregate(agg ethpb.SignedAggregateAttAndProof) {
 
 	s.savePending(root, agg, func(other any) bool {
 		a, ok := other.(ethpb.SignedAggregateAttAndProof)
-		return ok && pendingAggregatesAreEqual(agg, a)
+		return ok && pendingAggregatesAreEqual(agg, a, includeAggregatorIndex)
 	})
 }
 
@@ -391,13 +438,19 @@ func (s *Service) savePending(root [32]byte, pending any, isEqual func(other any
 	s.blkRootToPendingAtts[root] = append(s.blkRootToPendingAtts[root], pending)
 }
 
-func pendingAggregatesAreEqual(a, b ethpb.SignedAggregateAttAndProof) bool {
+// pendingAggregatesAreEqual checks if two pending aggregate attestations are equal.
+// The filter parameter controls whether aggregator index is considered in the equality check.
+func pendingAggregatesAreEqual(a, b ethpb.SignedAggregateAttAndProof, filter aggregatorIndexFilter) bool {
 	if a.Version() != b.Version() {
 		return false
 	}
-	if a.AggregateAttestationAndProof().GetAggregatorIndex() != b.AggregateAttestationAndProof().GetAggregatorIndex() {
-		return false
+
+	if filter == includeAggregatorIndex {
+		if a.AggregateAttestationAndProof().GetAggregatorIndex() != b.AggregateAttestationAndProof().GetAggregatorIndex() {
+			return false
+		}
 	}
+
 	aAtt := a.AggregateAttestationAndProof().AggregateVal()
 	bAtt := b.AggregateAttestationAndProof().AggregateVal()
 	if aAtt.GetData().Slot != bAtt.GetData().Slot {

beacon-chain/sync/pending_attestations_queue_test.go

@@ -94,7 +94,7 @@ func TestProcessPendingAtts_NoBlockRequestBlock(t *testing.T) {
 	// Process block A (which exists and has no pending attestations)
 	// This should skip processing attestations for A and request blocks B and C
 	require.NoError(t, r.processPendingAttsForBlock(t.Context(), rootA))
-	require.LogsContain(t, hook, "Requesting block by root")
+	require.LogsContain(t, hook, "Requesting blocks by root")
 }
 
 func TestProcessPendingAtts_HasBlockSaveUnaggregatedAtt(t *testing.T) {
@@ -911,17 +911,17 @@ func Test_pendingAggregatesAreEqual(t *testing.T) {
 					},
 					AggregationBits: bitfield.Bitlist{0b1111},
 				}}}
-		assert.Equal(t, true, pendingAggregatesAreEqual(a, b))
+		assert.Equal(t, true, pendingAggregatesAreEqual(a, b, includeAggregatorIndex))
 	})
 	t.Run("different version", func(t *testing.T) {
 		a := &ethpb.SignedAggregateAttestationAndProof{Message: &ethpb.AggregateAttestationAndProof{AggregatorIndex: 1}}
 		b := &ethpb.SignedAggregateAttestationAndProofElectra{Message: &ethpb.AggregateAttestationAndProofElectra{AggregatorIndex: 1}}
-		assert.Equal(t, false, pendingAggregatesAreEqual(a, b))
+		assert.Equal(t, false, pendingAggregatesAreEqual(a, b, includeAggregatorIndex))
 	})
 	t.Run("different aggregator index", func(t *testing.T) {
 		a := &ethpb.SignedAggregateAttestationAndProof{Message: &ethpb.AggregateAttestationAndProof{AggregatorIndex: 1}}
 		b := &ethpb.SignedAggregateAttestationAndProof{Message: &ethpb.AggregateAttestationAndProof{AggregatorIndex: 2}}
-		assert.Equal(t, false, pendingAggregatesAreEqual(a, b))
+		assert.Equal(t, false, pendingAggregatesAreEqual(a, b, includeAggregatorIndex))
 	})
 	t.Run("different slot", func(t *testing.T) {
 		a := &ethpb.SignedAggregateAttestationAndProof{
@@ -942,7 +942,7 @@ func Test_pendingAggregatesAreEqual(t *testing.T) {
 					},
 					AggregationBits: bitfield.Bitlist{0b1111},
 				}}}
-		assert.Equal(t, false, pendingAggregatesAreEqual(a, b))
+		assert.Equal(t, false, pendingAggregatesAreEqual(a, b, includeAggregatorIndex))
 	})
 	t.Run("different committee index", func(t *testing.T) {
 		a := &ethpb.SignedAggregateAttestationAndProof{
@@ -963,7 +963,7 @@ func Test_pendingAggregatesAreEqual(t *testing.T) {
 					},
 					AggregationBits: bitfield.Bitlist{0b1111},
 				}}}
-		assert.Equal(t, false, pendingAggregatesAreEqual(a, b))
+		assert.Equal(t, false, pendingAggregatesAreEqual(a, b, includeAggregatorIndex))
 	})
 	t.Run("different aggregation bits", func(t *testing.T) {
 		a := &ethpb.SignedAggregateAttestationAndProof{
@@ -984,7 +984,30 @@ func Test_pendingAggregatesAreEqual(t *testing.T) {
 					},
 					AggregationBits: bitfield.Bitlist{0b1000},
 				}}}
-		assert.Equal(t, false, pendingAggregatesAreEqual(a, b))
+		assert.Equal(t, false, pendingAggregatesAreEqual(a, b, includeAggregatorIndex))
+	})
+	t.Run("different aggregator index should be equal while ignoring aggregator index", func(t *testing.T) {
+		a := &ethpb.SignedAggregateAttestationAndProof{
+			Message: &ethpb.AggregateAttestationAndProof{
+				AggregatorIndex: 1,
+				Aggregate: &ethpb.Attestation{
+					Data: &ethpb.AttestationData{
+						Slot:           1,
+						CommitteeIndex: 1,
+					},
+					AggregationBits: bitfield.Bitlist{0b1111},
+				}}}
+		b := &ethpb.SignedAggregateAttestationAndProof{
+			Message: &ethpb.AggregateAttestationAndProof{
+				AggregatorIndex: 2,
+				Aggregate: &ethpb.Attestation{
+					Data: &ethpb.AttestationData{
+						Slot:           1,
+						CommitteeIndex: 1,
+					},
+					AggregationBits: bitfield.Bitlist{0b1111},
+				}}}
+		assert.Equal(t, true, pendingAggregatesAreEqual(a, b, ignoreAggregatorIndex))
 	})
 }
 

beacon-chain/sync/pending_blocks_queue.go

@@ -2,7 +2,6 @@ package sync
 
 import (
 	"context"
-	"encoding/hex"
 	"fmt"
 	"slices"
 	"sync"
@@ -44,11 +43,13 @@ func (s *Service) processPendingBlocksQueue() {
 		if !s.chainIsStarted() {
 			return
 		}
+
 		locker.Lock()
+		defer locker.Unlock()
+
 		if err := s.processPendingBlocks(s.ctx); err != nil {
 			log.WithError(err).Debug("Could not process pending blocks")
 		}
-		locker.Unlock()
 	})
 }
 
@@ -73,8 +74,10 @@ func (s *Service) processPendingBlocks(ctx context.Context) error {
 	randGen := rand.NewGenerator()
 	var parentRoots [][32]byte
 
+	blkRoots := make([][32]byte, 0, len(sortedSlots)*maxBlocksPerSlot)
+
 	// Iterate through sorted slots.
-	for _, slot := range sortedSlots {
+	for i, slot := range sortedSlots {
 		// Skip processing if slot is in the future.
 		if slot > s.cfg.clock.CurrentSlot() {
 			continue
@@ -91,6 +94,9 @@ func (s *Service) processPendingBlocks(ctx context.Context) error {
 
 		// Process each block in the queue.
 		for _, b := range blocksInCache {
+			start := time.Now()
+			totalDuration := time.Duration(0)
+
 			if err := blocks.BeaconBlockIsNil(b); err != nil {
 				continue
 			}
@@ -147,19 +153,34 @@ func (s *Service) processPendingBlocks(ctx context.Context) error {
 			}
 			cancelFunction()
 
-			// Process pending attestations for this block.
-			if err := s.processPendingAttsForBlock(ctx, blkRoot); err != nil {
-				log.WithError(err).Debug("Failed to process pending attestations for block")
-			}
+			blkRoots = append(blkRoots, blkRoot)
 
 			// Remove the processed block from the queue.
 			if err := s.removeBlockFromQueue(b, blkRoot); err != nil {
 				return err
 			}
-			log.WithFields(logrus.Fields{"slot": slot, "blockRoot": hex.EncodeToString(bytesutil.Trunc(blkRoot[:]))}).Debug("Processed pending block and cleared it in cache")
+
+			duration := time.Since(start)
+			totalDuration += duration
+			log.WithFields(logrus.Fields{
+				"slotIndex":     fmt.Sprintf("%d/%d", i+1, len(sortedSlots)),
+				"slot":          slot,
+				"root":          fmt.Sprintf("%#x", blkRoot),
+				"duration":      duration,
+				"totalDuration": totalDuration,
+			}).Debug("Processed pending block and cleared it in cache")
 		}
+
 		span.End()
 	}
+
+	for _, blkRoot := range blkRoots {
+		// Process pending attestations for this block.
+		if err := s.processPendingAttsForBlock(ctx, blkRoot); err != nil {
+			log.WithError(err).Debug("Failed to process pending attestations for block")
+		}
+	}
+
 	return s.sendBatchRootRequest(ctx, parentRoots, randGen)
 }
 
@@ -379,6 +400,19 @@ func (s *Service) sendBatchRootRequest(ctx context.Context, roots [][32]byte, ra
 			req = roots[:maxReqBlock]
 		}
 
+		if logrus.GetLevel() >= logrus.DebugLevel {
+			rootsStr := make([]string, 0, len(roots))
+			for _, req := range roots {
+				rootsStr = append(rootsStr, fmt.Sprintf("%#x", req))
+			}
+
+			log.WithFields(logrus.Fields{
+				"peer":  pid,
+				"count": len(req),
+				"roots": rootsStr,
+			}).Debug("Requesting blocks by root")
+		}
+
 		// Send the request to the peer.
 		if err := s.sendBeaconBlocksRequest(ctx, &req, pid); err != nil {
 			tracing.AnnotateError(span, err)
@@ -438,8 +472,6 @@ func (s *Service) filterOutPendingAndSynced(roots [][fieldparams.RootLength]byte
 			roots = append(roots[:i], roots[i+1:]...)
 			continue
 		}
-
-		log.WithField("blockRoot", fmt.Sprintf("%#x", r)).Debug("Requesting block by root")
 	}
 	return roots
 }

beacon-chain/sync/subscriber_beacon_blocks.go

@@ -189,12 +189,30 @@ func (s *Service) processDataColumnSidecarsFromExecution(ctx context.Context, so
 		ctx, cancel := context.WithTimeout(ctx, secondsPerHalfSlot)
 		defer cancel()
 
+		log := log.WithFields(logrus.Fields{
+			"root":          fmt.Sprintf("%#x", source.Root()),
+			"slot":          source.Slot(),
+			"proposerIndex": source.ProposerIndex(),
+			"type":          source.Type(),
+		})
+
+		var constructedSidecarCount uint64
 		for iteration := uint64(0); ; /*no stop condition*/ iteration++ {
+			log = log.WithField("iteration", iteration)
+
 			// Exit early if all sidecars to sample have been seen.
 			if s.haveAllSidecarsBeenSeen(source.Slot(), source.ProposerIndex(), columnIndicesToSample) {
+				if iteration > 0 && constructedSidecarCount == 0 {
+					log.Debug("No data column sidecars constructed from the execution client")
+				}
+
 				return nil, nil
 			}
 
+			if iteration == 0 {
+				dataColumnsRecoveredFromELAttempts.Inc()
+			}
+
 			// Try to reconstruct data column constructedSidecars from the execution client.
 			constructedSidecars, err := s.cfg.executionReconstructor.ConstructDataColumnSidecars(ctx, source)
 			if err != nil {
@@ -202,8 +220,8 @@ func (s *Service) processDataColumnSidecarsFromExecution(ctx context.Context, so
 			}
 
 			// No sidecars are retrieved from the EL, retry later
-			sidecarCount := uint64(len(constructedSidecars))
-			if sidecarCount == 0 {
+			constructedSidecarCount = uint64(len(constructedSidecars))
+			if constructedSidecarCount == 0 {
 				if ctx.Err() != nil {
 					return nil, ctx.Err()
 				}
@@ -212,9 +230,11 @@ func (s *Service) processDataColumnSidecarsFromExecution(ctx context.Context, so
 				continue
 			}
 
+			dataColumnsRecoveredFromELTotal.Inc()
+
 			// Boundary check.
-			if sidecarCount != fieldparams.NumberOfColumns {
-				return nil, errors.Errorf("reconstruct data column sidecars returned %d sidecars, expected %d - should never happen", sidecarCount, fieldparams.NumberOfColumns)
+			if constructedSidecarCount != fieldparams.NumberOfColumns {
+				return nil, errors.Errorf("reconstruct data column sidecars returned %d sidecars, expected %d - should never happen", constructedSidecarCount, fieldparams.NumberOfColumns)
 			}
 
 			unseenIndices, err := s.broadcastAndReceiveUnseenDataColumnSidecars(ctx, source.Slot(), source.ProposerIndex(), columnIndicesToSample, constructedSidecars)
@@ -222,19 +242,12 @@ func (s *Service) processDataColumnSidecarsFromExecution(ctx context.Context, so
 				return nil, errors.Wrap(err, "broadcast and receive unseen data column sidecars")
 			}
 
-			if len(unseenIndices) > 0 {
-				dataColumnsRecoveredFromELTotal.Inc()
+			log.WithFields(logrus.Fields{
+				"count":   len(unseenIndices),
+				"indices": helpers.SortedPrettySliceFromMap(unseenIndices),
+			}).Debug("Constructed data column sidecars from the execution client")
 
-				log.WithFields(logrus.Fields{
-					"root":          fmt.Sprintf("%#x", source.Root()),
-					"slot":          source.Slot(),
-					"proposerIndex": source.ProposerIndex(),
-					"iteration":     iteration,
-					"type":          source.Type(),
-					"count":         len(unseenIndices),
-					"indices":       helpers.SortedPrettySliceFromMap(unseenIndices),
-				}).Debug("Constructed data column sidecars from the execution client")
-			}
+			dataColumnSidecarsObtainedViaELCount.Observe(float64(len(unseenIndices)))
 
 			return nil, nil
 		}

beacon-chain/sync/validate_aggregate_proof.go

@@ -137,7 +137,9 @@ func (s *Service) validateAggregateAndProof(ctx context.Context, pid peer.ID, ms
 		return validationRes, err
 	}
 
-	s.setAggregatorIndexEpochSeen(data.Target.Epoch, m.AggregateAttestationAndProof().GetAggregatorIndex())
+	if first := s.setAggregatorIndexEpochSeen(data.Target.Epoch, m.AggregateAttestationAndProof().GetAggregatorIndex()); !first {
+		return pubsub.ValidationIgnore, nil
+	}
 
 	msg.ValidatorData = m
 
@@ -265,13 +267,19 @@ func (s *Service) hasSeenAggregatorIndexEpoch(epoch primitives.Epoch, aggregator
 }
 
 // Set aggregate's aggregator index target epoch as seen.
-func (s *Service) setAggregatorIndexEpochSeen(epoch primitives.Epoch, aggregatorIndex primitives.ValidatorIndex) {
+// Returns true if this is the first time seeing this aggregator index and epoch.
+func (s *Service) setAggregatorIndexEpochSeen(epoch primitives.Epoch, aggregatorIndex primitives.ValidatorIndex) bool {
 	b := append(bytesutil.Bytes32(uint64(epoch)), bytesutil.Bytes32(uint64(aggregatorIndex))...)
 
 	s.seenAggregatedAttestationLock.Lock()
 	defer s.seenAggregatedAttestationLock.Unlock()
 
+	_, seen := s.seenAggregatedAttestationCache.Get(string(b))
+	if seen {
+		return false
+	}
 	s.seenAggregatedAttestationCache.Add(string(b), true)
+	return true
 }
 
 // This validates the bitfield is correct and aggregator's index in state is within the beacon committee.

beacon-chain/sync/validate_aggregate_proof_test.go

@@ -801,3 +801,27 @@ func TestValidateAggregateAndProof_RejectWhenAttEpochDoesntEqualTargetEpoch(t *t
 	assert.NotNil(t, err)
 	assert.Equal(t, pubsub.ValidationReject, res)
 }
+
+func Test_SetAggregatorIndexEpochSeen(t *testing.T) {
+	db := dbtest.SetupDB(t)
+	p := p2ptest.NewTestP2P(t)
+
+	r := &Service{
+		cfg: &config{
+			p2p:      p,
+			beaconDB: db,
+		},
+		seenAggregatedAttestationCache: lruwrpr.New(10),
+	}
+
+	aggIndex := primitives.ValidatorIndex(42)
+	epoch := primitives.Epoch(7)
+
+	require.Equal(t, false, r.hasSeenAggregatorIndexEpoch(epoch, aggIndex))
+	first := r.setAggregatorIndexEpochSeen(epoch, aggIndex)
+	require.Equal(t, true, first)
+	require.Equal(t, true, r.hasSeenAggregatorIndexEpoch(epoch, aggIndex))
+
+	second := r.setAggregatorIndexEpochSeen(epoch, aggIndex)
+	require.Equal(t, false, second)
+}

beacon-chain/sync/validate_beacon_attestation.go

@@ -104,7 +104,8 @@ func (s *Service) validateCommitteeIndexBeaconAttestation(
 	}
 
 	if !s.slasherEnabled {
-		// Verify this the first attestation received for the participating validator for the slot.
+		// Verify this the first attestation received for the participating validator for the slot. This verification is here to return early if we've already seen this attestation.
+		// This verification is carried again later after all other validations to avoid TOCTOU issues.
 		if s.hasSeenUnaggregatedAtt(attKey) {
 			return pubsub.ValidationIgnore, nil
 		}
@@ -228,7 +229,10 @@ func (s *Service) validateCommitteeIndexBeaconAttestation(
 		Data: eventData,
 	})
 
-	s.setSeenUnaggregatedAtt(attKey)
+	if first := s.setSeenUnaggregatedAtt(attKey); !first {
+		// Another concurrent validation processed the same attestation meanwhile
+		return pubsub.ValidationIgnore, nil
+	}
 
 	// Attach final validated attestation to the message for further pipeline use
 	msg.ValidatorData = attForValidation
@@ -385,11 +389,16 @@ func (s *Service) hasSeenUnaggregatedAtt(key string) bool {
 }
 
 // Set an incoming attestation as seen for the participating validator for the slot.
-func (s *Service) setSeenUnaggregatedAtt(key string) {
+// Returns false if the attestation was already seen.
+func (s *Service) setSeenUnaggregatedAtt(key string) bool {
 	s.seenUnAggregatedAttestationLock.Lock()
 	defer s.seenUnAggregatedAttestationLock.Unlock()
-
+	_, seen := s.seenUnAggregatedAttestationCache.Get(key)
+	if seen {
+		return false
+	}
 	s.seenUnAggregatedAttestationCache.Add(key, true)
+	return true
 }
 
 // hasBlockAndState returns true if the beacon node knows about a block and associated state in the

beacon-chain/sync/validate_beacon_attestation_test.go

@@ -499,6 +499,10 @@ func TestService_setSeenUnaggregatedAtt(t *testing.T) {
 			Data:            &ethpb.AttestationData{Slot: 2, CommitteeIndex: 0},
 			AggregationBits: bitfield.Bitlist{0b1001},
 		}
+		s3c0a0 := &ethpb.Attestation{
+			Data:            &ethpb.AttestationData{Slot: 3, CommitteeIndex: 0},
+			AggregationBits: bitfield.Bitlist{0b1001},
+		}
 
 		t.Run("empty cache", func(t *testing.T) {
 			key := generateKey(t, s0c0a0)
@@ -506,26 +510,39 @@ func TestService_setSeenUnaggregatedAtt(t *testing.T) {
 		})
 		t.Run("ok", func(t *testing.T) {
 			key := generateKey(t, s0c0a0)
-			s.setSeenUnaggregatedAtt(key)
+			first := s.setSeenUnaggregatedAtt(key)
 			assert.Equal(t, true, s.hasSeenUnaggregatedAtt(key))
+			assert.Equal(t, true, first)
+		})
+		t.Run("already seen", func(t *testing.T) {
+			key := generateKey(t, s3c0a0)
+			first := s.setSeenUnaggregatedAtt(key)
+			assert.Equal(t, true, s.hasSeenUnaggregatedAtt(key))
+			assert.Equal(t, true, first)
+			first = s.setSeenUnaggregatedAtt(key)
+			assert.Equal(t, true, s.hasSeenUnaggregatedAtt(key))
+			assert.Equal(t, false, first)
 		})
 		t.Run("different slot", func(t *testing.T) {
 			key1 := generateKey(t, s1c0a0)
 			key2 := generateKey(t, s2c0a0)
-			s.setSeenUnaggregatedAtt(key1)
+			first := s.setSeenUnaggregatedAtt(key1)
 			assert.Equal(t, false, s.hasSeenUnaggregatedAtt(key2))
+			assert.Equal(t, true, first)
 		})
 		t.Run("different committee index", func(t *testing.T) {
 			key1 := generateKey(t, s0c1a0)
 			key2 := generateKey(t, s0c2a0)
-			s.setSeenUnaggregatedAtt(key1)
+			first := s.setSeenUnaggregatedAtt(key1)
 			assert.Equal(t, false, s.hasSeenUnaggregatedAtt(key2))
+			assert.Equal(t, true, first)
 		})
 		t.Run("different bit", func(t *testing.T) {
 			key1 := generateKey(t, s0c0a1)
 			key2 := generateKey(t, s0c0a2)
-			s.setSeenUnaggregatedAtt(key1)
+			first := s.setSeenUnaggregatedAtt(key1)
 			assert.Equal(t, false, s.hasSeenUnaggregatedAtt(key2))
+			assert.Equal(t, true, first)
 		})
 		t.Run("0 bits set is considered not seen", func(t *testing.T) {
 			a := &ethpb.Attestation{AggregationBits: bitfield.Bitlist{0b1000}}
@@ -576,6 +593,11 @@ func TestService_setSeenUnaggregatedAtt(t *testing.T) {
 			CommitteeId:   0,
 			AttesterIndex: 0,
 		}
+		s3c0a0 := &ethpb.SingleAttestation{
+			Data:          &ethpb.AttestationData{Slot: 2},
+			CommitteeId:   0,
+			AttesterIndex: 0,
+		}
 
 		t.Run("empty cache", func(t *testing.T) {
 			key := generateKey(t, s0c0a0)
@@ -583,26 +605,39 @@ func TestService_setSeenUnaggregatedAtt(t *testing.T) {
 		})
 		t.Run("ok", func(t *testing.T) {
 			key := generateKey(t, s0c0a0)
-			s.setSeenUnaggregatedAtt(key)
+			first := s.setSeenUnaggregatedAtt(key)
 			assert.Equal(t, true, s.hasSeenUnaggregatedAtt(key))
+			assert.Equal(t, true, first)
 		})
 		t.Run("different slot", func(t *testing.T) {
 			key1 := generateKey(t, s1c0a0)
 			key2 := generateKey(t, s2c0a0)
-			s.setSeenUnaggregatedAtt(key1)
+			first := s.setSeenUnaggregatedAtt(key1)
 			assert.Equal(t, false, s.hasSeenUnaggregatedAtt(key2))
+			assert.Equal(t, true, first)
+		})
+		t.Run("already seen", func(t *testing.T) {
+			key := generateKey(t, s3c0a0)
+			first := s.setSeenUnaggregatedAtt(key)
+			assert.Equal(t, true, s.hasSeenUnaggregatedAtt(key))
+			assert.Equal(t, true, first)
+			first = s.setSeenUnaggregatedAtt(key)
+			assert.Equal(t, true, s.hasSeenUnaggregatedAtt(key))
+			assert.Equal(t, false, first)
 		})
 		t.Run("different committee index", func(t *testing.T) {
 			key1 := generateKey(t, s0c1a0)
 			key2 := generateKey(t, s0c2a0)
-			s.setSeenUnaggregatedAtt(key1)
+			first := s.setSeenUnaggregatedAtt(key1)
 			assert.Equal(t, false, s.hasSeenUnaggregatedAtt(key2))
+			assert.Equal(t, true, first)
 		})
 		t.Run("different attester", func(t *testing.T) {
 			key1 := generateKey(t, s0c0a1)
 			key2 := generateKey(t, s0c0a2)
-			s.setSeenUnaggregatedAtt(key1)
+			first := s.setSeenUnaggregatedAtt(key1)
 			assert.Equal(t, false, s.hasSeenUnaggregatedAtt(key2))
+			assert.Equal(t, true, first)
 		})
 		t.Run("single attestation is considered not seen", func(t *testing.T) {
 			a := &ethpb.AttestationElectra{}

beacon-chain/sync/validate_data_column.go

@@ -51,14 +51,12 @@ func (s *Service) validateDataColumn(ctx context.Context, pid peer.ID, msg *pubs
 	// Decode the message, reject if it fails.
 	m, err := s.decodePubsubMessage(msg)
 	if err != nil {
-		log.WithError(err).Error("Failed to decode message")
 		return pubsub.ValidationReject, err
 	}
 
 	// Reject messages that are not of the expected type.
 	dcsc, ok := m.(*eth.DataColumnSidecar)
 	if !ok {
-		log.WithField("message", m).Error("Message is not of type *eth.DataColumnSidecar")
 		return pubsub.ValidationReject, errWrongMessage
 	}
 

beacon-chain/sync/validate_light_client_test.go

@@ -54,11 +54,13 @@ func TestValidateLightClientOptimisticUpdate(t *testing.T) {
 	cfg.CapellaForkEpoch = 3
 	cfg.DenebForkEpoch = 4
 	cfg.ElectraForkEpoch = 5
+	cfg.FuluForkEpoch = 6
 	cfg.ForkVersionSchedule[[4]byte{1, 0, 0, 0}] = 1
 	cfg.ForkVersionSchedule[[4]byte{2, 0, 0, 0}] = 2
 	cfg.ForkVersionSchedule[[4]byte{3, 0, 0, 0}] = 3
 	cfg.ForkVersionSchedule[[4]byte{4, 0, 0, 0}] = 4
 	cfg.ForkVersionSchedule[[4]byte{5, 0, 0, 0}] = 5
+	cfg.ForkVersionSchedule[[4]byte{6, 0, 0, 0}] = 6
 	params.OverrideBeaconConfig(cfg)
 
 	secondsPerSlot := int(params.BeaconConfig().SecondsPerSlot)
@@ -101,7 +103,10 @@ func TestValidateLightClientOptimisticUpdate(t *testing.T) {
 	}
 
 	for _, test := range tests {
-		for v := 1; v < 6; v++ {
+		for v := range version.All() {
+			if v == version.Phase0 {
+				continue
+			}
 			t.Run(test.name+"_"+version.String(v), func(t *testing.T) {
 				ctx := t.Context()
 				p := p2ptest.NewTestP2P(t)
@@ -180,11 +185,13 @@ func TestValidateLightClientFinalityUpdate(t *testing.T) {
 	cfg.CapellaForkEpoch = 3
 	cfg.DenebForkEpoch = 4
 	cfg.ElectraForkEpoch = 5
+	cfg.FuluForkEpoch = 6
 	cfg.ForkVersionSchedule[[4]byte{1, 0, 0, 0}] = 1
 	cfg.ForkVersionSchedule[[4]byte{2, 0, 0, 0}] = 2
 	cfg.ForkVersionSchedule[[4]byte{3, 0, 0, 0}] = 3
 	cfg.ForkVersionSchedule[[4]byte{4, 0, 0, 0}] = 4
 	cfg.ForkVersionSchedule[[4]byte{5, 0, 0, 0}] = 5
+	cfg.ForkVersionSchedule[[4]byte{6, 0, 0, 0}] = 6
 	params.OverrideBeaconConfig(cfg)
 
 	secondsPerSlot := int(params.BeaconConfig().SecondsPerSlot)
@@ -227,7 +234,10 @@ func TestValidateLightClientFinalityUpdate(t *testing.T) {
 	}
 
 	for _, test := range tests {
-		for v := 1; v < 6; v++ {
+		for v := range version.All() {
+			if v == version.Phase0 {
+				continue
+			}
 			t.Run(test.name+"_"+version.String(v), func(t *testing.T) {
 				ctx := t.Context()
 				p := p2ptest.NewTestP2P(t)

beacon-chain/verification/data_column.go

@@ -361,7 +361,7 @@ func (dv *RODataColumnsVerifier) SidecarParentSeen(parentSeen func([fieldparams.
 		}
 
 		if !dv.fc.HasNode(parentRoot) {
-			return columnErrBuilder(errSidecarParentNotSeen)
+			return columnErrBuilder(errors.Wrapf(errSidecarParentNotSeen, "parent root: %#x", parentRoot))
 		}
 	}
 

changelog/Fibonacci747_chore-remove-dead-stol-param.md

@@ -1,3 +0,0 @@
-### Changed
-
-- Removed dead slot parameter from blobCacheEntry.filter

changelog/Forostovec_fix-execution-option.md

@@ -1,3 +0,0 @@
-## Changed
-
-- Avoid redundant WithHttpEndpoint when JWT is provided

changelog/Galoretka_convert-progress.md

@@ -1,3 +0,0 @@
-### Fixed
-
-- Fix proposals progress bar count [#16020](https://github.com/OffchainLabs/prysm/pull/16020)

changelog/SashaMalysehko_fix-return-after-check.md

@@ -0,0 +1,3 @@
+## Fixed
+
+- Fix missing return after version header check in SubmitAttesterSlashingsV2.

changelog/Snezhkko_fix-type.md

@@ -0,0 +1,3 @@
+## Fixed
+
+- incorrect constructor return type [#16084](https://github.com/OffchainLabs/prysm/pull/16084)

changelog/aarsh-revert-autonatv2.md

@@ -0,0 +1,2 @@
+### Ignored
+- Reverts AutoNatV2 change introduced in https://github.com/OffchainLabs/prysm/pull/16100 as the libp2p upgrade fails inter-op testing.

changelog/avoid_kzg_send_after_context_cancel.md

@@ -0,0 +1,3 @@
+### Fixed
+
+- Prevent blocked sends to the KZG batch verifier when the caller context is already canceled, avoiding useless queueing and potential hangs.

changelog/bastin_fix-lcp2p-bug.md

@@ -0,0 +1,3 @@
+### Fixed
+
+- Fix the missing fork version object mapping for Fulu in light client p2p.

changelog/bastin_has-state-using-diff.md

@@ -1,3 +0,0 @@
-### Added
-
-- Integrate state-diff into `HasState()`.

changelog/bastin_refactor-slot-by-blkroot.md

@@ -1,3 +0,0 @@
-### Ignored
-
-- Refactor finding slot by block root using state summary and block to its own function.

changelog/bastin_state-diff-anchor-slot-bug.md

@@ -1,3 +0,0 @@
-### Fixed
-
-- Fix state diff repetitive anchor slot bug.

changelog/bastin_state-diff-configs.md

@@ -1,4 +0,0 @@
-### Added
-
-- Add initial configs for the state-diff feature.
-- Add kv functions for the state-diff feature.

changelog/bastin_state-read-diff.md

@@ -1,3 +0,0 @@
-### Added
-
-- Integrate state-diff into `State()`.

changelog/bastin_update-lc-for-fulu.md

@@ -1,3 +0,0 @@
-### Added
-
-- add fulu support to light client processing.

changelog/bharath_add-metric-for-attestation-gossip-verification.md

@@ -1,2 +0,0 @@
-### Added
-- prometheus metric `gossip_attestation_verification_milliseconds` to track attestation gossip topic validation latency.

changelog/builder-index.md

@@ -0,0 +1,3 @@
+### Added
+
+- `primitives.BuilderIndex`: SSZ `uint64` wrapper for builder registry indices.

changelog/chris-downgrade-log-level.md

@@ -1,4 +0,0 @@
-### Changed
-
-- Downgraded log level from INFO to DEBUG on PrepareBeaconProposer updated fee recipients.
-- Change the logging behaviour of Updated fee recipients to only log count of validators at Debug level and all validator indices at Trace level.

changelog/dbxe_fulu-interop.md

@@ -1,2 +0,0 @@
-### Ignored
-- Add osaka fork timestamp derivation to interop genesis

changelog/fix_kzg_batch_verifier_timeout_deadlock.md

@@ -0,0 +1,3 @@
+### Fixed
+
+- Fix deadlock in data column gossip KZG batch verification when a caller times out preventing result delivery.

changelog/james-prysm_align-atter-pool-apis.md

@@ -0,0 +1,3 @@
+### Changed
+
+- the /eth/v2/beacon/pool/attestations and /eth/v1/beacon/pool/sync_committees now returns a 503 error if the node is still syncing, the rest api is also working in a similar process to gRPC broadcasting immediately now.

changelog/james-prysm_fix-fork-start-e2e.md

@@ -1,3 +0,0 @@
-### Fixed
-
-- fixes E2E tests to be able to start from Electra genesis fork or future forks

changelog/james-prysm_fix-rest-replay-state.md

@@ -0,0 +1,3 @@
+### Fixed 
+
+- fixed replay state issue in rest api caused by attester and sync committee duties endpoints

changelog/james-prysm_optimize-get-blobs.md

@@ -1,3 +0,0 @@
-### Ignored
-
-- optimization to remove cell and blob proof computation on blob rest api.

changelog/james-prysm_semi-supernode.md

@@ -1,2 +0,0 @@
-### Added
-- Added `--semi-supernode` flag to custody half of a super node's datacolumn requirements but allowing for reconstruction for blob retrieval

changelog/james-prysm_skip-e2e-slot1-check.md

@@ -0,0 +1,3 @@
+### Changed
+
+- e2e sync committee evaluator now skips the first slot after startup, we already skip the fork epoch for checks here, this skip only applies on startup, due to altair always from 0 and validators need to warm up.

changelog/james-prysm_supernode-alias.md

@@ -1,3 +0,0 @@
-### Changed
-
-- Changed `--subscribe-all-data-subnets` flag to `--supernode` and aliased `--subscribe-all-data-subnets` for existing users.

changelog/kasey_backfill-data-columns.md

@@ -1,7 +0,0 @@
-### Added
-- Data column backfill.
-- Backfill metrics for columns: backfill_data_column_sidecar_downloaded, backfill_data_column_sidecar_downloaded_bytes, backfill_batch_columns_download_ms, backfill_batch_columns_verify_ms.
-
-### Changed
-- backfill metrics that changed name and/or histogram buckets: backfill_batch_time_verify -> backfill_batch_verify_ms, backfill_batch_time_waiting -> backfill_batch_waiting_ms, backfill_batch_time_roundtrip -> backfill_batch_roundtrip_ms, backfill_blocks_bytes_downloaded -> backfill_blocks_downloaded_bytes, backfill_batch_time_verify -> backfill_batch_verify_ms, backfill_batch_blocks_time_download -> backfill_batch_blocks_download_ms, backfill_batch_blobs_time_download -> backfill_batch_blobs_download_ms, backfill_blobs_bytes_downloaded -> backfill_blocks_downloaded_bytes, 
-

changelog/kasey_fix-backfill-flag.md

@@ -0,0 +1,2 @@
+#### Fixed
+- Fix validation logic for `--backfill-oldest-slot`, which was rejecting slots newer than 1056767.

changelog/late-block-dont-fire-attribute.md

@@ -1,3 +0,0 @@
-### Changed
-
-- Stop emitting payload attribute events during late block handling when we are not proposing the next slot

changelog/manu-agg.md

@@ -0,0 +1,3 @@
+### Changed
+
+- Pending aggregates: When multiple aggregated attestations only differing by the aggregator index are in the pending queue, only process one of them.

changelog/manu-logs-beacon-chain.md

@@ -1,3 +0,0 @@
-### Changed
-
-- `blobsDataFromStoredDataColumns`: Ask the use to use the `--supernode` flag and shorten the error mesage.