chore(taiko-client): ensure event block IDs are continuous (#18775)

packages/taiko-client/pkg/chain_iterator/block_batch_iterator.go

@@ -20,6 +20,7 @@ const (
 	DefaultBlocksReadPerEpoch = 1000
 	DefaultRetryInterval      = 12 * time.Second
 	DefaultBlockConfirmations = 0
+	BackOffMaxRetries         = 5
 )
 
 var (
@@ -163,7 +164,13 @@ func (i *BlockBatchIterator) Iter() error {
 		return nil
 	}
 
-	if err := backoff.Retry(iterOp, backoff.WithContext(backoff.NewConstantBackOff(i.retryInterval), i.ctx)); err != nil {
+	if err := backoff.Retry(
+		iterOp,
+		backoff.WithMaxRetries(
+			backoff.WithContext(backoff.NewConstantBackOff(i.retryInterval), i.ctx),
+			BackOffMaxRetries,
+		),
+	); err != nil {
 		return err
 	}
 

packages/taiko-client/pkg/chain_iterator/event_iterator/block_proposed_iterator.go

@@ -3,6 +3,7 @@ package eventiterator
 import (
 	"context"
 	"errors"
+	"fmt"
 	"math/big"
 
 	"github.com/ethereum/go-ethereum/accounts/abi/bind"
@@ -110,7 +111,10 @@ func assembleBlockProposedIteratorCallback(
 		updateCurrentFunc chainIterator.UpdateCurrentFunc,
 		endFunc chainIterator.EndIterFunc,
 	) error {
-		endHeight := end.Number.Uint64()
+		var (
+			endHeight   = end.Number.Uint64()
+			lastBlockID uint64
+		)
 
 		log.Debug("Iterating BlockProposed events", "start", start.Number, "end", endHeight)
 
@@ -127,6 +131,20 @@ func assembleBlockProposedIteratorCallback(
 			event := iterOntake.Event
 			log.Debug("Processing BlockProposedV2 event", "block", event.BlockId, "l1BlockHeight", event.Raw.BlockNumber)
 
+			if lastBlockID != 0 && event.BlockId.Uint64() != lastBlockID+1 {
+				log.Warn(
+					"BlockProposedV2 event is not continuous, rescan the L1 chain",
+					"fromL1Block", start.Number,
+					"toL1Block", endHeight,
+					"lastScannedBlockID", lastBlockID,
+					"currentScannedBlockID", event.BlockId.Uint64(),
+				)
+				return fmt.Errorf(
+					"BlockProposedV2 event is not continuous, lastScannedBlockID: %d, currentScannedBlockID: %d",
+					lastBlockID, event.BlockId.Uint64(),
+				)
+			}
+
 			if err := callback(ctx, metadata.NewTaikoDataBlockMetadataOntake(event), eventIter.end); err != nil {
 				log.Warn("Error while processing BlockProposedV2 events, keep retrying", "error", err)
 				return err
@@ -145,6 +163,8 @@ func assembleBlockProposedIteratorCallback(
 
 			log.Debug("Updating current block cursor for processing BlockProposedV2 events", "block", current.Number)
 
+			lastBlockID = event.BlockId.Uint64()
+
 			updateCurrentFunc(current)
 		}