diff --git a/api/service/stagedstreamsync/const.go b/api/service/stagedstreamsync/const.go
index 5c735d764b..048b5d812d 100644
--- a/api/service/stagedstreamsync/const.go
+++ b/api/service/stagedstreamsync/const.go
@@ -23,9 +23,6 @@ const (
 	// no more request will be assigned to workers to wait for InsertChain to finish.
 	SoftQueueCap int = 100
 
-	// DefaultConcurrency is the default settings for concurrency
-	DefaultConcurrency int = 4
-
 	// ShortRangeTimeout is the timeout for each short range sync, which allow short range sync
 	// to restart automatically when stuck in `getBlockHashes`
 	ShortRangeTimeout time.Duration = 1 * time.Minute
@@ -74,10 +71,10 @@ type (
 
 func (c *Config) fixValues() {
 	if c.Concurrency == 0 {
-		c.Concurrency = DefaultConcurrency
+		c.Concurrency = c.MinStreams
 	}
 	if c.Concurrency > c.MinStreams {
-		c.MinStreams = c.Concurrency
+		c.Concurrency = c.MinStreams
 	}
 	if c.MinStreams > c.InitStreams {
 		c.InitStreams = c.MinStreams
diff --git a/api/service/stagedstreamsync/downloader.go b/api/service/stagedstreamsync/downloader.go
index 96add97fd3..3711048955 100644
--- a/api/service/stagedstreamsync/downloader.go
+++ b/api/service/stagedstreamsync/downloader.go
@@ -153,6 +153,17 @@ func (d *Downloader) SubscribeDownloadFinished(ch chan struct{}) event.Subscript
 // waitForBootFinish waits for stream manager to finish the initial discovery and have
 // enough peers to start downloader
 func (d *Downloader) waitForBootFinish() {
+	bootCompleted, numStreams := d.waitForEnoughStreams(d.config.InitStreams)
+	if bootCompleted {
+		fmt.Printf("boot completed for shard %d ( %d streams are connected )\n",
+			d.bc.ShardID(), numStreams)
+	}
+}
+
+func (d *Downloader) waitForEnoughStreams(requiredStreams int) (bool, int) {
+	d.logger.Info().Int("requiredStreams", requiredStreams).
+		Msg("waiting for enough stream connections to continue syncing")
+
 	evtCh := make(chan streammanager.EvtStreamAdded, 1)
 	sub := d.syncProtocol.SubscribeAddStreamEvent(evtCh)
 	defer sub.Unsubscribe()
@@ -177,12 +188,11 @@ func (d *Downloader) waitForBootFinish() {
 			trigger()
 
 		case <-checkCh:
-			if d.syncProtocol.NumStreams() >= d.config.InitStreams {
-				fmt.Printf("boot completed for shard %d ( %d streams are connected )\n", d.bc.ShardID(), d.syncProtocol.NumStreams())
-				return
+			if d.syncProtocol.NumStreams() >= requiredStreams {
+				return true, d.syncProtocol.NumStreams()
 			}
 		case <-d.closeC:
-			return
+			return false, d.syncProtocol.NumStreams()
 		}
 	}
 }
@@ -212,6 +222,9 @@ func (d *Downloader) loop() {
 		case <-d.downloadC:
 			bnBeforeSync := d.bc.CurrentBlock().NumberU64()
 			estimatedHeight, addedBN, err := d.stagedSyncInstance.doSync(d.ctx, initSync)
+			if err == ErrNotEnoughStreams {
+				d.waitForEnoughStreams(d.config.MinStreams)
+			}
 			if err != nil {
 				//TODO: if there is a bad block which can't be resolved
 				if d.stagedSyncInstance.invalidBlock.Active {
diff --git a/api/service/stagedstreamsync/errors.go b/api/service/stagedstreamsync/errors.go
index d18020dd06..9f1e1eb60b 100644
--- a/api/service/stagedstreamsync/errors.go
+++ b/api/service/stagedstreamsync/errors.go
@@ -14,7 +14,7 @@ var (
 	ErrUnexpectedNumberOfBlockHashes = WrapStagedSyncError("unexpected number of getBlocksByHashes result")
 	ErrUnexpectedBlockHashes         = WrapStagedSyncError("unexpected get block hashes result delivered")
 	ErrNilBlock                      = WrapStagedSyncError("nil block found")
-	ErrNotEnoughStreams              = WrapStagedSyncError("not enough streams")
+	ErrNotEnoughStreams              = WrapStagedSyncError("number of streams smaller than minimum required")
 	ErrParseCommitSigAndBitmapFail   = WrapStagedSyncError("parse commitSigAndBitmap failed")
 	ErrVerifyHeaderFail              = WrapStagedSyncError("verify header failed")
 	ErrInsertChainFail               = WrapStagedSyncError("insert to chain failed")
diff --git a/api/service/stagedstreamsync/short_range_helper.go b/api/service/stagedstreamsync/short_range_helper.go
index 42327c78df..aa6b785120 100644
--- a/api/service/stagedstreamsync/short_range_helper.go
+++ b/api/service/stagedstreamsync/short_range_helper.go
@@ -7,6 +7,7 @@ import (
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/harmony-one/harmony/core/types"
+	"github.com/harmony-one/harmony/internal/utils"
 	syncProto "github.com/harmony-one/harmony/p2p/stream/protocols/sync"
 	sttypes "github.com/harmony-one/harmony/p2p/stream/types"
 	"github.com/pkg/errors"
@@ -132,6 +133,10 @@ func (sh *srHelper) getBlocksByHashes(ctx context.Context, hashes []common.Hash,
 
 func (sh *srHelper) checkPrerequisites() error {
 	if sh.syncProtocol.NumStreams() < sh.config.Concurrency {
+		utils.Logger().Info().
+			Int("available streams", sh.syncProtocol.NumStreams()).
+			Interface("concurrency", sh.config.Concurrency).
+			Msg("not enough streams to do concurrent processes")
 		return ErrNotEnoughStreams
 	}
 	return nil
diff --git a/api/service/stagedstreamsync/stage_bodies.go b/api/service/stagedstreamsync/stage_bodies.go
index 4996ea78b7..b5d92e3a1a 100644
--- a/api/service/stagedstreamsync/stage_bodies.go
+++ b/api/service/stagedstreamsync/stage_bodies.go
@@ -167,13 +167,22 @@ func (b *StageBodies) runBlockWorkerLoop(ctx context.Context, gbm *blockDownload
 				Msg(WrapStagedSyncMsg("downloadRawBlocks failed"))
 			err = errors.Wrap(err, "request error")
 			gbm.HandleRequestError(batch, err, stid)
-		} else if blockBytes == nil || len(blockBytes) == 0 {
+		} else if blockBytes == nil {
 			utils.Logger().Warn().
 				Str("stream", string(stid)).
 				Interface("block numbers", batch).
-				Msg(WrapStagedSyncMsg("downloadRawBlocks failed, received empty blockBytes"))
+				Msg(WrapStagedSyncMsg("downloadRawBlocks failed, received invalid (nil) blockBytes"))
+			err := errors.New("downloadRawBlocks received invalid (nil) blockBytes")
+			gbm.HandleRequestError(batch, err, stid)
+			b.configs.protocol.StreamFailed(stid, "downloadRawBlocks failed")
+		} else if len(blockBytes) == 0 {
+			utils.Logger().Warn().
+				Str("stream", string(stid)).
+				Interface("block numbers", batch).
+				Msg(WrapStagedSyncMsg("downloadRawBlocks failed, received empty blockBytes, remote peer is not fully synced"))
 			err := errors.New("downloadRawBlocks received empty blockBytes")
 			gbm.HandleRequestError(batch, err, stid)
+			b.configs.protocol.RemoveStream(stid)
 		} else {
 			if err = b.saveBlocks(ctx, gbm.tx, batch, blockBytes, sigBytes, loopID, stid); err != nil {
 				panic(ErrSaveBlocksToDbFailed)
diff --git a/api/service/stagedstreamsync/stage_epoch.go b/api/service/stagedstreamsync/stage_epoch.go
index 2c51aa1f94..e84b74f340 100644
--- a/api/service/stagedstreamsync/stage_epoch.go
+++ b/api/service/stagedstreamsync/stage_epoch.go
@@ -92,7 +92,12 @@ func (sr *StageEpoch) doShortRangeSyncForEpochSync(ctx context.Context, s *Stage
 	}
 
 	if err := sh.checkPrerequisites(); err != nil {
-		return 0, errors.Wrap(err, "prerequisite")
+		// if error is ErrNotEnoughStreams but still some streams available,
+		// it can continue syncing, otherwise return error
+		// here we are not doing concurrent processes, so even 1 stream should be enough
+		if err != ErrNotEnoughStreams || s.state.protocol.NumStreams() == 0 {
+			return 0, errors.Wrap(err, "prerequisite")
+		}
 	}
 	curBN := s.state.bc.CurrentBlock().NumberU64()
 	bns := make([]uint64, 0, BlocksPerRequest)
diff --git a/api/service/stagedstreamsync/stage_short_range.go b/api/service/stagedstreamsync/stage_short_range.go
index 54534bfbb1..ce6cdf36bc 100644
--- a/api/service/stagedstreamsync/stage_short_range.go
+++ b/api/service/stagedstreamsync/stage_short_range.go
@@ -97,7 +97,12 @@ func (sr *StageShortRange) doShortRangeSync(ctx context.Context, s *StageState)
 	}
 
 	if err := sh.checkPrerequisites(); err != nil {
-		return 0, errors.Wrap(err, "prerequisite")
+		// if error is ErrNotEnoughStreams but still two streams available,
+		// it can continue syncing, otherwise return error
+		// at least 2 streams are needed to do concurrent processes
+		if err != ErrNotEnoughStreams || s.state.protocol.NumStreams() < 2 {
+			return 0, errors.Wrap(err, "prerequisite")
+		}
 	}
 	curBN := sr.configs.bc.CurrentBlock().NumberU64()
 	blkNums := sh.prepareBlockHashNumbers(curBN)
diff --git a/api/service/stagedstreamsync/staged_stream_sync.go b/api/service/stagedstreamsync/staged_stream_sync.go
index 3cd8756604..1592186b52 100644
--- a/api/service/stagedstreamsync/staged_stream_sync.go
+++ b/api/service/stagedstreamsync/staged_stream_sync.go
@@ -337,8 +337,9 @@ func (s *StagedStreamSync) promLabels() prometheus.Labels {
 func (s *StagedStreamSync) checkHaveEnoughStreams() error {
 	numStreams := s.protocol.NumStreams()
 	if numStreams < s.config.MinStreams {
-		return fmt.Errorf("number of streams smaller than minimum: %v < %v",
+		s.logger.Debug().Msgf("number of streams smaller than minimum: %v < %v",
 			numStreams, s.config.MinStreams)
+		return ErrNotEnoughStreams
 	}
 	return nil
 }
diff --git a/cmd/harmony/default.go b/cmd/harmony/default.go
index 4cc20cfdf4..50c3815f4b 100644
--- a/cmd/harmony/default.go
+++ b/cmd/harmony/default.go
@@ -232,7 +232,7 @@ var (
 		Downloader:           true,
 		StagedSync:           false,
 		StagedSyncCfg:        defaultStagedSyncConfig,
-		Concurrency:          4,
+		Concurrency:          2,
 		MinPeers:             2,
 		InitStreams:          2,
 		MaxAdvertiseWaitTime: 2, //minutes
diff --git a/p2p/stream/common/requestmanager/interface_test.go b/p2p/stream/common/requestmanager/interface_test.go
index c51303ccba..dd9c772fb8 100644
--- a/p2p/stream/common/requestmanager/interface_test.go
+++ b/p2p/stream/common/requestmanager/interface_test.go
@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"strconv"
 	"sync"
+	"time"
 
 	"github.com/ethereum/go-ethereum/event"
 	"github.com/ethereum/go-ethereum/rlp"
@@ -118,7 +119,7 @@ func (st *testStream) FailedTimes() int {
 	return 0
 }
 
-func (st *testStream) AddFailedTimes() {
+func (st *testStream) AddFailedTimes(faultRecoveryThreshold time.Duration) {
 	return
 }
 
diff --git a/p2p/stream/common/streammanager/interface_test.go b/p2p/stream/common/streammanager/interface_test.go
index 5a9bb44366..6933615f9a 100644
--- a/p2p/stream/common/streammanager/interface_test.go
+++ b/p2p/stream/common/streammanager/interface_test.go
@@ -6,6 +6,7 @@ import (
 	"strconv"
 	"sync"
 	"sync/atomic"
+	"time"
 
 	sttypes "github.com/harmony-one/harmony/p2p/stream/types"
 	"github.com/libp2p/go-libp2p/core/network"
@@ -74,7 +75,7 @@ func (st *testStream) FailedTimes() int {
 	return 0
 }
 
-func (st *testStream) AddFailedTimes() {
+func (st *testStream) AddFailedTimes(faultRecoveryThreshold time.Duration) {
 	return
 }
 
diff --git a/p2p/stream/protocols/sync/chain_test.go b/p2p/stream/protocols/sync/chain_test.go
index 3f3f68b889..ac3d292add 100644
--- a/p2p/stream/protocols/sync/chain_test.go
+++ b/p2p/stream/protocols/sync/chain_test.go
@@ -215,3 +215,18 @@ func checkBlocksByHashesResult(b []byte, hs []common.Hash) error {
 	}
 	return nil
 }
+
+func checkGetReceiptsResult(b []byte, hs []common.Hash) error {
+	var msg = &syncpb.Message{}
+	if err := protobuf.Unmarshal(b, msg); err != nil {
+		return err
+	}
+	bhResp, err := msg.GetReceiptsResponse()
+	if err != nil {
+		return err
+	}
+	if len(hs) != len(bhResp.Receipts) {
+		return errors.New("unexpected size")
+	}
+	return nil
+}
diff --git a/p2p/stream/protocols/sync/const.go b/p2p/stream/protocols/sync/const.go
index 745ed35ba9..afcd21fea7 100644
--- a/p2p/stream/protocols/sync/const.go
+++ b/p2p/stream/protocols/sync/const.go
@@ -26,7 +26,11 @@ const (
 	GetReceiptsCap = 10
 
 	// MaxStreamFailures is the maximum allowed failures before stream gets removed
-	MaxStreamFailures = 3
+	MaxStreamFailures = 5
+
+	// FaultRecoveryThreshold is the minimum duration before it resets the previous failures
+	// So, if stream hasn't had any issue for a certain amount of time since last failure, we can still trust it
+	FaultRecoveryThreshold = 30 * time.Minute
 
 	// minAdvertiseInterval is the minimum advertise interval
 	minAdvertiseInterval = 1 * time.Minute
diff --git a/p2p/stream/protocols/sync/protocol.go b/p2p/stream/protocols/sync/protocol.go
index ca4590c972..538b2b9b8a 100644
--- a/p2p/stream/protocols/sync/protocol.go
+++ b/p2p/stream/protocols/sync/protocol.go
@@ -272,13 +272,16 @@ func (p *Protocol) RemoveStream(stID sttypes.StreamID) {
 		st.Close()
 		// stream manager removes this stream from the list and triggers discovery if number of streams are not enough
 		p.sm.RemoveStream(stID) //TODO: double check to see if this part is needed
+		p.logger.Info().
+			Str("stream ID", string(stID)).
+			Msg("stream removed")
 	}
 }
 
 func (p *Protocol) StreamFailed(stID sttypes.StreamID, reason string) {
 	st, exist := p.sm.GetStreamByID(stID)
 	if exist && st != nil {
-		st.AddFailedTimes()
+		st.AddFailedTimes(FaultRecoveryThreshold)
 		p.logger.Info().
 			Str("stream ID", string(st.ID())).
 			Int("num failures", st.FailedTimes()).
diff --git a/p2p/stream/types/stream.go b/p2p/stream/types/stream.go
index 18b47f6158..12581b7de0 100644
--- a/p2p/stream/types/stream.go
+++ b/p2p/stream/types/stream.go
@@ -5,6 +5,7 @@ import (
 	"encoding/binary"
 	"io"
 	"sync"
+	"time"
 
 	libp2p_network "github.com/libp2p/go-libp2p/core/network"
 	"github.com/pkg/errors"
@@ -22,7 +23,7 @@ type Stream interface {
 	Close() error
 	CloseOnExit() error
 	FailedTimes() int
-	AddFailedTimes()
+	AddFailedTimes(faultRecoveryThreshold time.Duration)
 	ResetFailedTimes()
 }
 
@@ -38,7 +39,8 @@ type BaseStream struct {
 	specErr  error
 	specOnce sync.Once
 
-	failedTimes int
+	failedTimes     int
+	lastFailureTime time.Time
 }
 
 // NewBaseStream creates BaseStream as the wrapper of libp2p Stream
@@ -82,8 +84,15 @@ func (st *BaseStream) FailedTimes() int {
 	return st.failedTimes
 }
 
-func (st *BaseStream) AddFailedTimes() {
+func (st *BaseStream) AddFailedTimes(faultRecoveryThreshold time.Duration) {
+	if st.failedTimes > 0 {
+		durationSinceLastFailure := time.Now().Sub(st.lastFailureTime)
+		if durationSinceLastFailure >= faultRecoveryThreshold {
+			st.ResetFailedTimes()
+		}
+	}
 	st.failedTimes++
+	st.lastFailureTime = time.Now()
 }
 
 func (st *BaseStream) ResetFailedTimes() {