log: reduce logs when receiving too much votes from a peer

eth/handler_bsc.go

@@ -62,7 +62,6 @@ func (h *bscHandler) Handle(peer *bsc.Peer, packet bsc.Packet) error {
 // votes broadcast for the local node to process.
 func (h *bscHandler) handleVotesBroadcast(peer *bsc.Peer, votes []*types.VoteEnvelope) error {
 	if peer.IsOverLimitAfterReceiving() {
-		peer.Log().Warn("peer sending votes too much, votes dropped; it may be a ddos attack, please check!")
 		return nil
 	}
 	// Here we only put the first vote, to avoid ddos attack by sending a large batch of votes.

eth/protocols/bsc/peer.go

@@ -26,7 +26,7 @@ const (
 	receiveRateLimitPerSecond = 10
 
 	// the time span of one period
-	secondsPerPeriod = float64(10)
+	secondsPerPeriod = float64(30)
 )
 
 // max is a helper function which returns the larger of the two given integers.
@@ -133,6 +133,9 @@ func (p *Peer) AsyncSendVotes(votes []*types.VoteEnvelope) {
 // Otherwise, check whether the number of received votes extra (secondsPerPeriod * receiveRateLimitPerSecond)
 func (p *Peer) IsOverLimitAfterReceiving() bool {
 	if timeInterval := time.Since(p.periodBegin).Seconds(); timeInterval >= secondsPerPeriod {
+		if p.periodCounter > uint(secondsPerPeriod*receiveRateLimitPerSecond) {
+			p.Log().Debug("sending votes too much", "secondsPerPeriod", secondsPerPeriod, "count ", p.periodCounter)
+		}
 		p.periodBegin = time.Now()
 		p.periodCounter = 0
 		return false