Validator: Add trace span information for AttestationRecord save requests (#11742)

* Add additional span information when saving attestation records

* Remove keymanager.sign span. It's very noisy and not a helpful data point.

Co-authored-by: prylabs-bulldozer[bot] <58059840+prylabs-bulldozer[bot]@users.noreply.github.com>

validator/db/kv/attester_protection.go

@@ -20,6 +20,13 @@ import (
 // SlashingKind used for helpful information upon detection.
 type SlashingKind int
 
+// AttestationRecordSaveRequest includes the attestation record to save along
+// with the appropriate call context.
+type AttestationRecordSaveRequest struct {
+	ctx    context.Context
+	record *AttestationRecord
+}
+
 // AttestationRecord which can be represented by these simple values
 // for manipulation by database methods.
 type AttestationRecord struct {
@@ -304,17 +311,23 @@ func (s *Store) SaveAttestationForPubKey(
 ) error {
 	ctx, span := trace.StartSpan(ctx, "Validator.SaveAttestationForPubKey")
 	defer span.End()
-	s.batchedAttestationsChan <- &AttestationRecord{
-		PubKey:      pubKey,
-		Source:      att.Data.Source.Epoch,
-		Target:      att.Data.Target.Epoch,
-		SigningRoot: signingRoot,
+	s.batchedAttestationsChan <- &AttestationRecordSaveRequest{
+		ctx: ctx,
+		record: &AttestationRecord{
+			PubKey:      pubKey,
+			Source:      att.Data.Source.Epoch,
+			Target:      att.Data.Target.Epoch,
+			SigningRoot: signingRoot,
+		},
 	}
+
 	// Subscribe to be notified when the attestation record queued
 	// for saving to the DB is indeed saved. If an error occurred
 	// during the process of saving the attestation record, the sender
 	// will give us that error. We use a buffered channel
 	// to prevent blocking the sender from notifying us of the result.
+	_, innerSpan := trace.StartSpan(ctx, "Validator.SaveAttestationForPubKey.WaitForResponse")
+	defer innerSpan.End()
 	responseChan := make(chan saveAttestationsResponse, 1)
 	defer close(responseChan)
 	sub := s.batchAttestationsFlushedFeed.Subscribe(responseChan)
@@ -335,15 +348,24 @@ func (s *Store) batchAttestationWrites(ctx context.Context) {
 	for {
 		select {
 		case v := <-s.batchedAttestationsChan:
-			s.batchedAttestations.Append(v)
+			_, span := trace.StartSpan(v.ctx, "batchAttestationWrites.handleBatchedAttestationSaveRequest")
+			s.batchedAttestations.Append(v.record)
+
+			span.AddAttributes(trace.Int64Attribute("num_records", int64(s.batchedAttestations.Len())))
+
 			if numRecords := s.batchedAttestations.Len(); numRecords >= attestationBatchCapacity {
 				log.WithField("numRecords", numRecords).Debug(
 					"Reached max capacity of batched attestation records, flushing to DB",
 				)
 				if s.batchedAttestationsFlushInProgress.IsNotSet() {
-					s.flushAttestationRecords(ctx, s.batchedAttestations.Flush())
+					// Create a new context with the span information from the chan. This is to
+					// prevent any context deadlines from the caller while maintaining the trace
+					// relationships.
+					ctx2 := trace.NewContext(ctx, span)
+					s.flushAttestationRecords(ctx2, s.batchedAttestations.Flush())
 				}
 			}
+			span.End()
 		case <-ticker.C:
 			if numRecords := s.batchedAttestations.Len(); numRecords > 0 {
 				log.WithField("numRecords", numRecords).Debug(
@@ -364,6 +386,9 @@ func (s *Store) batchAttestationWrites(ctx context.Context) {
 // This function notifies all subscribers for flushed attestations
 // of the result of the save operation.
 func (s *Store) flushAttestationRecords(ctx context.Context, records []*AttestationRecord) {
+	ctx, span := trace.StartSpan(ctx, "validatorDB.flushAttestationRecords")
+	defer span.End()
+
 	if s.batchedAttestationsFlushInProgress.IsSet() {
 		// This should never happen. This method should not be called when a flush is already in
 		// progress. If you are seeing this log, check the atomic bool before calling this method.
@@ -381,6 +406,7 @@ func (s *Store) flushAttestationRecords(ctx context.Context, records []*Attestat
 	} else {
 		// This should never happen.
 		log.WithError(err).Error("Failed to batch save attestation records, retrying in queue")
+		tracing.AnnotateError(span, err)
 		for _, ar := range records {
 			s.batchedAttestations.Append(ar)
 		}

validator/db/kv/db.go

@@ -64,7 +64,7 @@ type Store struct {
 	db                                 *bolt.DB
 	databasePath                       string
 	batchedAttestations                *QueuedAttestationRecords
-	batchedAttestationsChan            chan *AttestationRecord
+	batchedAttestationsChan            chan *AttestationRecordSaveRequest
 	batchAttestationsFlushedFeed       *event.Feed
 	batchedAttestationsFlushInProgress abool.AtomicBool
 }
@@ -134,7 +134,7 @@ func NewKVStore(ctx context.Context, dirPath string, config *Config) (*Store, er
 		db:                           boltDB,
 		databasePath:                 dirPath,
 		batchedAttestations:          NewQueuedAttestationRecords(),
-		batchedAttestationsChan:      make(chan *AttestationRecord, attestationBatchCapacity),
+		batchedAttestationsChan:      make(chan *AttestationRecordSaveRequest, attestationBatchCapacity),
 		batchAttestationsFlushedFeed: new(event.Feed),
 	}
 

validator/keymanager/local/keymanager.go

@@ -200,9 +200,6 @@ func (km *Keymanager) FetchValidatingPrivateKeys(ctx context.Context) ([][32]byt
 
 // Sign signs a message using a validator key.
 func (_ *Keymanager) Sign(ctx context.Context, req *validatorpb.SignRequest) (bls.Signature, error) {
-	ctx, span := trace.StartSpan(ctx, "keymanager.Sign")
-	defer span.End()
-
 	publicKey := req.PublicKey
 	if publicKey == nil {
 		return nil, errors.New("nil public key in request")