Fetch blocks concurrently but send in order

cmd/main.go

@@ -82,7 +82,7 @@ func main() {
 		rpcClient,
 		duneClient,
 		ingester.Config{
-			MaxBatchSize:           1,
+			MaxBatchSize:           cfg.Concurrency,
 			ReportProgressInterval: cfg.ReportProgressInterval,
 			PollInterval:           cfg.PollInterval,
 			Stack:                  cfg.RPCStack,

config/config.go

@@ -40,6 +40,7 @@ type Config struct {
 	ReportProgressInterval time.Duration `long:"report-progress-interval" env:"REPORT_PROGRESS_INTERVAL" description:"Interval to report progress" default:"30s"` // nolint:lll
 	RPCNode                RPCClient
 	RPCStack               models.EVMStack `long:"rpc-stack" env:"RPC_STACK" description:"Stack for the RPC client" default:"opstack"` // nolint:lll
+	Concurrency            int             `long:"concurrency" env:"CONCURRENCY" description:"Number of concurrent workers"`           // nolint:lll
 }
 
 func (c Config) HasError() error {

ingester/ingester.go

@@ -14,17 +14,22 @@ type Ingester interface {
 	// Run starts the ingester and blocks until the context is cancelled or maxCount blocks are ingested
 	Run(ctx context.Context, startBlockNumber int64, maxCount int64) error
 
-	// ConsumeBlocks sends blocks from startBlockNumber to endBlockNumber to outChan, inclusive.
+	// ProduceBlockNumbers sends block numbers from startBlockNumber to endBlockNumber to outChan, inclusive.
 	// If endBlockNumber is -1, it sends blocks from startBlockNumber to the tip of the chain
 	// it will run continuously until the context is cancelled
-	ConsumeBlocks(ctx context.Context, outChan chan models.RPCBlock, startBlockNumber int64, endBlockNumber int64) error
+	ProduceBlockNumbers(ctx context.Context, outChan chan int64, startBlockNumber int64, endBlockNumber int64) error
+
+	// ConsumeBlocks fetches blocks sent on the channel and sends them on the other channel.
+	// It will run continuously until the context is cancelled, or the channel is closed.
+	// It can safely be run concurrently.
+	ConsumeBlocks(context.Context, chan int64, chan models.RPCBlock) error
 
 	// SendBlocks pushes to DuneAPI the RPCBlock Payloads as they are received in an endless loop
 	// it will block until:
 	//	- the context is cancelled
 	//  - channel is closed
 	//  - a fatal error occurs
-	SendBlocks(ctx context.Context, blocksCh <-chan models.RPCBlock) error
+	SendBlocks(ctx context.Context, blocksCh <-chan models.RPCBlock, startFrom int64) error
 
 	// This is just a placeholder for now
 	Info() Info
@@ -33,7 +38,7 @@ type Ingester interface {
 }
 
 const (
-	defaultMaxBatchSize           = 1
+	defaultMaxBatchSize           = 5
 	defaultPollInterval           = 1 * time.Second
 	defaultReportProgressInterval = 30 * time.Second
 )

ingester/mainloop.go

@@ -11,54 +11,64 @@ import (
 	"golang.org/x/sync/errgroup"
 )
 
+// Run fetches blocks from a node RPC and sends them in order to the Dune API.
+//
+// ProduceBlockNumbers (blockNumbers channel) -> ConsumeBlocks (blocks channel) -> SendBlocks -> Dune
+//
+// We produce block numbers to fetch on an unbuffered channel (ProduceBlockNumbers),
+// and each concurrent ConsumeBlock goroutine gets a block number from that channel.
+// The SendBlocks goroutine receives all blocks on an unbuffered channel,
+// but buffers them in a map until they can be sent in order.
 func (i *ingester) Run(ctx context.Context, startBlockNumber int64, maxCount int64) error {
 	ctx, cancel := context.WithCancel(ctx)
+	errGroup, ctx := errgroup.WithContext(ctx)
 
-	inFlightChan := make(chan models.RPCBlock, i.cfg.MaxBatchSize) // we close this after ConsumeBlocks has returned
-
-	// Ingest until endBlockNumber, inclusive. If maxCount is <= 0, we ingest forever
-	endBlockNumber := startBlockNumber - 1 + maxCount
-
-	i.log.Info("Starting ingester",
-		"maxBatchSize", i.cfg.MaxBatchSize,
-		"startBlockNumber", startBlockNumber,
-		"endBlockNumber", endBlockNumber,
-		"maxCount", maxCount,
-	)
+	blockNumbers := make(chan int64)
+	defer close(blockNumbers)
+	blocks := make(chan models.RPCBlock)
+	defer close(blocks)
 
-	errGroup, ctx := errgroup.WithContext(ctx)
+	// Start MaxBatchSize goroutines to consume blocks concurrently
+	for range i.cfg.MaxBatchSize {
+		errGroup.Go(func() error {
+			return i.ConsumeBlocks(ctx, blockNumbers, blocks)
+		})
+	}
 	errGroup.Go(func() error {
-		return i.SendBlocks(ctx, inFlightChan)
+		return i.ReportProgress(ctx)
 	})
 	errGroup.Go(func() error {
-		return i.ReportProgress(ctx)
+		return i.SendBlocks(ctx, blocks, startBlockNumber)
 	})
 
-	err := i.ConsumeBlocks(ctx, inFlightChan, startBlockNumber, endBlockNumber)
-	close(inFlightChan)
-	cancel()
-	if err != nil {
-		if err := errGroup.Wait(); err != nil {
-			i.log.Error("errgroup wait", "error", err)
-		}
-		return errors.Errorf("consume blocks: %w", err)
-	}
+	// Ingest until endBlockNumber, inclusive. If maxCount is <= 0, we ingest forever
+	endBlockNumber := startBlockNumber - 1 + maxCount
+	i.log.Info("Starting ingester",
+		"max_batch_size", i.cfg.MaxBatchSize,
+		"run_forever", maxCount <= 0,
+		"start_block_number", startBlockNumber,
+		"end_block_number", endBlockNumber,
+		"batch_size", i.cfg.MaxBatchSize,
+	)
 
-	if err := errGroup.Wait(); err != nil && err != ErrFinishedConsumeBlocks {
-		return err
-	}
+	// Produce block numbers in the main goroutine
+	err := i.ProduceBlockNumbers(ctx, blockNumbers, startBlockNumber, endBlockNumber)
+	i.log.Info("ProduceBlockNumbers is done", "error", err)
+	i.log.Info("Cancelling context")
+	cancel()
 
-	return nil
+	return errGroup.Wait()
 }
 
 var ErrFinishedConsumeBlocks = errors.New("finished ConsumeBlocks")
 
-// ConsumeBlocks from the NPC Node
-func (i *ingester) ConsumeBlocks(
-	ctx context.Context, outChan chan models.RPCBlock, startBlockNumber, endBlockNumber int64,
+// ProduceBlockNumbers to be consumed by multiple goroutines running ConsumeBlocks
+func (i *ingester) ProduceBlockNumbers(
+	ctx context.Context, blockNumbers chan int64, startBlockNumber int64, endBlockNumber int64,
 ) error {
 	latestBlockNumber := i.tryUpdateLatestBlockNumber()
 
+	// Helper function
 	waitForBlock := func(ctx context.Context, blockNumber int64, latestBlockNumber int64) int64 {
 		for blockNumber > latestBlockNumber {
 			select {
@@ -77,82 +87,126 @@ func (i *ingester) ConsumeBlocks(
 
 	// Consume blocks forever if end is before start. This happens if Run is called with a maxCount of <= 0
 	dontStop := endBlockNumber < startBlockNumber
-
+	i.log.Info("Produce block numbers from", "startBlockNumber", startBlockNumber, "endBlockNumber", endBlockNumber)
 	for blockNumber := startBlockNumber; dontStop || blockNumber <= endBlockNumber; blockNumber++ {
 		latestBlockNumber = waitForBlock(ctx, blockNumber, latestBlockNumber)
-		startTime := time.Now()
-
-		i.log.Info("Getting block by number", "blockNumber", blockNumber, "latestBlockNumber", latestBlockNumber)
-		block, err := i.node.BlockByNumber(ctx, blockNumber)
-		if err != nil {
-			if errors.Is(err, context.Canceled) {
-				i.log.Info("Context canceled, stopping..")
-				return ctx.Err()
-			}
-
-			i.log.Error("Failed to get block by number, continuing..",
-				"blockNumber", blockNumber,
-				"latestBlockNumber", latestBlockNumber,
-				"error", err,
-			)
-			i.info.RPCErrors = append(i.info.RPCErrors, ErrorInfo{
-				Timestamp:   time.Now(),
-				BlockNumber: blockNumber,
-				Error:       err,
-			})
-
-			// TODO: should I sleep (backoff) here?
-			continue
-		}
-
-		atomic.StoreInt64(&i.info.ConsumedBlockNumber, block.BlockNumber)
-		getBlockElapsed := time.Since(startTime)
 
 		select {
 		case <-ctx.Done():
+			i.log.Info("ProduceBlockNumbers: Context canceled, stopping")
 			return ctx.Err()
-		case outChan <- block:
+		case blockNumbers <- blockNumber:
 		}
 
-		distanceFromLatest := latestBlockNumber - block.BlockNumber
+		distanceFromLatest := latestBlockNumber - blockNumber
 		if distanceFromLatest > 0 {
 			// TODO: improve logs of processing speed and catchup estimated ETA
 			i.log.Info("We're behind, trying to catch up..",
-				"blockNumber", block.BlockNumber,
+				"blockNumber", blockNumber,
 				"latestBlockNumber", latestBlockNumber,
 				"distanceFromLatest", distanceFromLatest,
-				"getBlockElapsedMillis", getBlockElapsed.Milliseconds(),
-				"elapsedMillis", time.Since(startTime).Milliseconds(),
 			)
 		}
 	}
-	// Done consuming blocks, either because we reached the endBlockNumber or the context was canceled
-	i.log.Info("Finished consuming blocks", "latestBlockNumber", latestBlockNumber, "endBlockNumber", endBlockNumber)
+	i.log.Info("Finished producing block numbers")
 	return ErrFinishedConsumeBlocks
 }
 
-func (i *ingester) SendBlocks(ctx context.Context, blocksCh <-chan models.RPCBlock) error {
-	for payload := range blocksCh {
-		// TODO: we should batch RCP blocks here before sending to Dune.
-		if err := i.dune.SendBlock(ctx, payload); err != nil {
-			if errors.Is(err, context.Canceled) {
-				i.log.Info("Context canceled, stopping..")
+// ConsumeBlocks from the RPC node. This can be run in multiple goroutines to parallelize block fetching.
+func (i *ingester) ConsumeBlocks(
+	ctx context.Context, blockNumbers chan int64, blocks chan models.RPCBlock,
+) error {
+	for {
+		select {
+		case <-ctx.Done():
+			i.log.Info("ConsumeBlocks: context is done")
+			return ctx.Err()
+		case blockNumber := <-blockNumbers:
+			startTime := time.Now()
+
+			i.log.Info("Getting block by number", "blockNumber", blockNumber)
+			block, err := i.node.BlockByNumber(ctx, blockNumber)
+			if err != nil {
+				if errors.Is(err, context.Canceled) {
+					i.log.Info("ConsumeBlocks: Context canceled, stopping")
+					return ctx.Err()
+				}
+
+				i.log.Error("Failed to get block by number, continuing..",
+					"blockNumber", blockNumber,
+					"error", err,
+				)
+				i.info.RPCErrors = append(i.info.RPCErrors, ErrorInfo{
+					Timestamp:   time.Now(),
+					BlockNumber: blockNumber,
+					Error:       err,
+				})
+
+				// TODO: should we sleep (backoff) here?
+				continue
+			}
+
+			atomic.StoreInt64(&i.info.ConsumedBlockNumber, block.BlockNumber)
+			getBlockElapsed := time.Since(startTime)
+			i.log.Info("Got block by number", "blockNumber", blockNumber, "elapsed", getBlockElapsed)
+			select {
+			case <-ctx.Done():
+				i.log.Info("ConsumeBlocks: Channel is closed, not sending block to channel", "blockNumber", block.BlockNumber)
 				return ctx.Err()
+			case blocks <- block:
+				i.log.Info("Sent block")
+			}
+		}
+	}
+}
+
+// SendBlocks to Dune. We receive blocks from the ConsumeBlocks goroutines, potentially out of order.
+// We buffer the blocks in a map until we have no gaps, so that we can send them in order to Dune.
+func (i *ingester) SendBlocks(ctx context.Context, blocksCh <-chan models.RPCBlock, startBlockNumber int64) error {
+	i.log.Info("SendBlocks: Starting to receive blocks")
+	blockMap := make(map[int64]models.RPCBlock) // Buffer for temporarily storing blocks that have arrived out of order
+	next := startBlockNumber
+	for {
+		select {
+		case <-ctx.Done():
+			i.log.Info("SendBlocks: Context canceled, stopping")
+			return ctx.Err()
+		case block, ok := <-blocksCh:
+			if !ok {
+				i.log.Info("SendBlocks: Channel is closed, returning")
+				return nil
+			}
+
+			blockMap[block.BlockNumber] = block
+			i.log.Info("Received block", "blockNumber", block.BlockNumber)
+
+			// Send this block only if we have sent all previous blocks
+			for block, ok := blockMap[next]; ok; block, ok = blockMap[next] {
+				i.log.Info("SendBlocks: Sending block to DuneAPI", "blockNumber", block.BlockNumber)
+				if err := i.dune.SendBlock(ctx, block); err != nil {
+					if errors.Is(err, context.Canceled) {
+						i.log.Info("SendBlocks: Context canceled, stopping")
+						return ctx.Err()
+					}
+					// TODO: implement DeadLetterQueue
+					// this will leave a "block gap" in DuneAPI, TODO: implement a way to fill this gap
+					i.log.Error("SendBlocks: Failed, continuing", "blockNumber", block.BlockNumber, "error", err)
+					i.info.DuneErrors = append(i.info.DuneErrors, ErrorInfo{
+						Timestamp:   time.Now(),
+						BlockNumber: block.BlockNumber,
+						Error:       err,
+					})
+				} else {
+					i.log.Info("Updating latest ingested block number", "blockNumber", block.BlockNumber)
+					atomic.StoreInt64(&i.info.IngestedBlockNumber, block.BlockNumber)
+				}
+
+				// We've sent block N, so increment the pointer
+				delete(blockMap, next)
+				next++
 			}
-			// TODO: implement DeadLetterQueue
-			// this will leave a "block gap" in DuneAPI, TODO: implement a way to fill this gap
-			i.log.Error("SendBlock failed, continuing..", "blockNumber", payload.BlockNumber, "error", err)
-			i.info.DuneErrors = append(i.info.DuneErrors, ErrorInfo{
-				Timestamp:   time.Now(),
-				BlockNumber: payload.BlockNumber,
-				Error:       err,
-			})
-		} else {
-			i.log.Info("Updating latest ingested block number", "blockNumber", payload.BlockNumber)
-			atomic.StoreInt64(&i.info.IngestedBlockNumber, payload.BlockNumber)
 		}
 	}
-	return ctx.Err() // channel closed
 }
 
 func (i *ingester) tryUpdateLatestBlockNumber() int64 {
@@ -183,7 +237,7 @@ func (i *ingester) ReportProgress(ctx context.Context) error {
 
 			blocksPerSec := float64(lastIngested-previousIngested) / tNow.Sub(previousTime).Seconds()
 			newDistance := latest - lastIngested
-			fallingBehind := newDistance > (previousDistance + 1) // TODO: make is more stable
+			fallingBehind := newDistance > (previousDistance + 1) // TODO: make this more stable
 
 			rpcErrors := len(i.info.RPCErrors)
 			duneErrors := len(i.info.DuneErrors)