Feature flag to disable head update on attestation basis (#4802)

beacon-chain/blockchain/process_attestation.go

@@ -11,6 +11,7 @@ import (
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
 	"github.com/prysmaticlabs/prysm/beacon-chain/flags"
 	"github.com/prysmaticlabs/prysm/shared/bytesutil"
+	"github.com/prysmaticlabs/prysm/shared/featureconfig"
 	"go.opencensus.io/trace"
 )
 
@@ -128,9 +129,11 @@ func (s *Service) onAttestation(ctx context.Context, a *ethpb.Attestation) ([]ui
 	// Update forkchoice store with the new attestation for updating weight.
 	s.forkChoiceStore.ProcessAttestation(ctx, indexedAtt.AttestingIndices, bytesutil.ToBytes32(a.Data.BeaconBlockRoot), a.Data.Target.Epoch)
 
-	// Update fork choice head after updating weight.
-	if err := s.updateHead(ctx, baseState.Balances()); err != nil {
-		return nil, err
+	if !featureconfig.Get().DisableUpdateHeadPerAttestation {
+		// Update fork choice head after updating weight.
+		if err := s.updateHead(ctx, baseState.Balances()); err != nil {
+			return nil, err
+		}
 	}
 
 	return indexedAtt.AttestingIndices, nil

beacon-chain/sync/rpc_goodbye.go

@@ -27,7 +27,7 @@ func (r *Service) goodbyeRPCHandler(ctx context.Context, msg interface{}, stream
 	defer cancel()
 	setRPCStreamDeadlines(stream)
 
-	m, ok:= msg.(uint64)
+	m, ok := msg.(uint64)
 	if !ok {
 		return fmt.Errorf("wrong message type for goodbye, got %T, wanted uint64", msg)
 	}

shared/featureconfig/config.go

@@ -42,6 +42,7 @@ type Flags struct {
 	ProtectAttester                            bool   // ProtectAttester prevents the validator client from signing any attestations that would be considered a slashable offense.
 	ForkchoiceAggregateAttestations            bool   // ForkchoiceAggregateAttestations attempts to aggregate attestations before processing in fork choice.
 	DisableStrictAttestationPubsubVerification bool   // DisableStrictAttestationPubsubVerification will disabling strict signature verification in pubsub.
+	DisableUpdateHeadPerAttestation            bool   // DisableUpdateHeadPerAttestation will disabling update head on per attestation basis.
 
 	// DisableForkChoice disables using LMD-GHOST fork choice to update
 	// the head of the chain based on attestations and instead accepts any valid received block
@@ -148,6 +149,10 @@ func ConfigureBeaconChain(ctx *cli.Context) {
 		log.Warn("Disabled strict attestation signature verification in pubsub")
 		cfg.DisableStrictAttestationPubsubVerification = true
 	}
+	if ctx.GlobalBool(disableUpdateHeadPerAttestation.Name) {
+		log.Warn("Disabled update head on per attestation basis")
+		cfg.DisableUpdateHeadPerAttestation = true
+	}
 
 	Init(cfg)
 }

shared/featureconfig/flags.go

@@ -98,6 +98,10 @@ var (
 		Name:  "disable-strict-attestation-pubsub-verification",
 		Usage: "Disable strict signature verification of attestations in pubsub. See PR 4782 for details.",
 	}
+	disableUpdateHeadPerAttestation = cli.BoolFlag{
+		Name:  "disable-update-head-attestation",
+		Usage: "Disable update fork choice head on per attestation. See PR 4802 for details.",
+	}
 )
 
 // Deprecated flags list.
@@ -249,6 +253,7 @@ var BeaconChainFlags = append(deprecatedFlags, []cli.Flag{
 	cacheFilteredBlockTreeFlag,
 	forkchoiceAggregateAttestations,
 	disableStrictAttestationPubsubVerificationFlag,
+	disableUpdateHeadPerAttestation,
 }...)
 
 // E2EBeaconChainFlags contains a list of the beacon chain feature flags to be tested in E2E.