diff --git a/session-dealer/mysql/model.go b/session-dealer/mysql/model.go
index a9c9210..b59fd14 100644
--- a/session-dealer/mysql/model.go
+++ b/session-dealer/mysql/model.go
@@ -110,6 +110,9 @@ func (crs *coverRanges) addRange(node *coverageNode)  {
 			node.next = checkRange
 			node = nil
 			break
+
+		} else {
+			currRange = checkRange
 		}
 	}
 	if node != nil {
@@ -121,14 +124,16 @@ func (crs *coverRanges) addRange(node *coverageNode)  {
 
 func (crs *coverRanges) mergeRanges()  {
 	// merge ranges
-	currRange := crs.head;
-	if currRange.next != nil {
+	currRange := crs.head
+	for currRange.next != nil {
 		checkRange := currRange.next
 		if currRange.end >= checkRange.begin && currRange.end < checkRange.end {
 			currRange.end = checkRange.end
 			currRange.next = checkRange.next
-
 			checkRange.Recovery()
+
+		} else {
+			currRange = currRange.next
 		}
 	}
 }
\ No newline at end of file
diff --git a/session-dealer/mysql/session.go b/session-dealer/mysql/session.go
index efdd441..6a75f1b 100644
--- a/session-dealer/mysql/session.go
+++ b/session-dealer/mysql/session.go
@@ -182,17 +182,13 @@ func (ms *MysqlSession) readFromClient(seqID int64, bytes []byte) {
 			log.Debugf("in session %s get outdate package with Seq:%d, beginSeq:%d",
 				*ms.connectionID, seqID, ms.beginSeqID)
 			return
-
-		} else if seqID + int64(len(bytes)) <= ms.beginSeqID {
-			// repeat packet
-			log.Debugf("receive repeat packet")
 		}
 
 		seqOffset := seqID - ms.beginSeqID
 		if seqOffset+contentSize > int64(len(ms.cachedStmtBytes)) {
 			// not in a normal mysql packet
 			log.Debugf("receive an unexpect packet")
-			// ms.clear()
+			 ms.clear()
 			return
 		}