diff --git a/eth/downloader/fetchers_concurrent.go b/eth/downloader/fetchers_concurrent.go
index 87f34dcca1..c120c77794 100644
--- a/eth/downloader/fetchers_concurrent.go
+++ b/eth/downloader/fetchers_concurrent.go
@@ -36,6 +36,8 @@ var timeoutGracePeriod = 2 * time.Minute
 // peersRetryInterval is the retry interval when all peers cannot get the request data.
 var peersRetryInterval = 100 * time.Millisecond
 
+var maxRetries = 10
+
 // typedQueue is an interface defining the adaptor needed to translate the type
 // specific downloader/queue schedulers into the type-agnostic general concurrent
 // fetcher algorithm calls.
@@ -128,6 +130,8 @@ func (d *Downloader) concurrentFetch(queue typedQueue, beaconMode bool) error {
 
 	// Prepare the queue and fetch block parts until the block header fetcher's done
 	finished := false
+
+	requestRetried := 0
 	for {
 		// Short circuit if we lost all our peers
 		if d.peers.Len() == 0 && !beaconMode {
@@ -139,6 +143,9 @@ func (d *Downloader) concurrentFetch(queue typedQueue, beaconMode bool) error {
 				return nil
 			}
 		} else {
+			if requestRetried > 0 {
+				log.Debug("Krish: step into retry logic else...")
+			}
 			// Send a download request to all idle peers, until throttled
 			var (
 				idles []*peerConnection
@@ -161,6 +168,10 @@ func (d *Downloader) concurrentFetch(queue typedQueue, beaconMode bool) error {
 			}
 			sort.Sort(&peerCapacitySort{idles, caps})
 
+			if requestRetried > 0 {
+				log.Info("Krish: idles num", "idles count = ", len(idles))
+			}
+
 			var (
 				progressed bool
 				throttled  bool
@@ -170,9 +181,11 @@ func (d *Downloader) concurrentFetch(queue typedQueue, beaconMode bool) error {
 				// Short circuit if throttling activated or there are no more
 				// queued tasks to be retrieved
 				if throttled {
+					log.Info("Krish: throttled")
 					break
 				}
 				if queued = queue.pending(); queued == 0 {
+					log.Info("Krish: queued == 0")
 					break
 				}
 				// Reserve a chunk of fetches for a peer. A nil can mean either that
@@ -189,9 +202,16 @@ func (d *Downloader) concurrentFetch(queue typedQueue, beaconMode bool) error {
 				if request == nil {
 					continue
 				}
+
+				if requestRetried > 0 {
+					log.Info("Krish: queue reserve success", "request header", request.Headers[0].Number)
+				}
+
 				// Fetch the chunk and make sure any errors return the hashes to the queue
 				req, err := queue.request(peer, request, responses)
 				if err != nil {
+					log.Info("Krish: queue.request error", "request header", request.Headers[0].Number, "err is", err)
+
 					// Sending the request failed, which generally means the peer
 					// was disconnected in between assignment and network send.
 					// Although all peer removal operations return allocated tasks
@@ -199,9 +219,9 @@ func (d *Downloader) concurrentFetch(queue typedQueue, beaconMode bool) error {
 					// immediately pushing the unfulfilled requests.
 					queue.unreserve(peer.id) // TODO(karalabe): This needs a non-expiration method
 					//reset progressed
-					if len(pending) == 0 {
-						progressed = false
-					}
+					//if len(pending) == 0 {
+					//	progressed = false
+					//}
 					continue
 				}
 				pending[peer.id] = req
@@ -222,6 +242,11 @@ func (d *Downloader) concurrentFetch(queue typedQueue, beaconMode bool) error {
 			// Retry the unreserved task in next loop
 			if len(pending) == 0 && queued > 0 && beaconMode {
 				log.Warn("All idle peers are not valid for current task, will retry ...")
+				requestRetried++
+				if requestRetried > maxRetries {
+					log.Info("max retry exceeded, cancel request")
+					return errCanceled
+				}
 				time.Sleep(peersRetryInterval)
 				continue
 			}