diff --git a/api/service/syncing/syncing.go b/api/service/syncing/syncing.go
index 187501d5c..167226f92 100644
--- a/api/service/syncing/syncing.go
+++ b/api/service/syncing/syncing.go
@@ -29,14 +29,11 @@ import (
 // Constants for syncing.
 const (
 	downloadBlocksRetryLimit        = 5 // downloadBlocks service retry limit
-	TimesToFail                     = 5 // downloadBlocks service retry limit
 	RegistrationNumber              = 3
 	SyncingPortDifference           = 3000
 	inSyncThreshold                 = 0    // when peerBlockHeight - myBlockHeight <= inSyncThreshold, it's ready to join consensus
-	syncStatusCheckCount            = 3    // check this many times before confirming it's out of sync
 	SyncLoopBatchSize        uint32 = 1000 // maximum size for one query of block hashes
 	verifyHeaderBatchSize    uint64 = 100  // block chain header verification batch size
-	SyncLoopFrequency               = 1    // unit in second
 	LastMileBlocksSize              = 50
 
 	// after cutting off a number of connected peers, the result number of peers
diff --git a/consensus/consensus_v2.go b/consensus/consensus_v2.go
index 29e7f4433..067f980c2 100644
--- a/consensus/consensus_v2.go
+++ b/consensus/consensus_v2.go
@@ -158,6 +158,9 @@ func (consensus *Consensus) finalCommit() {
 	}
 
 	// if leader successfully finalizes the block, send committed message to validators
+	// Note: leader already sent 67% commit in preCommit. The 100% commit won't be sent immediately
+	// to save network traffic. It will only be sent in retry if consensus doesn't move forward.
+	// Or if the leader is changed for next block, the 100% committed sig will be sent to the next leader immediately.
 	sendImmediately := false
 	if !consensus.IsLeader() || block.IsLastBlockInEpoch() {
 		sendImmediately = true