diff --git a/source/dnode/mnode/impl/src/mndConsumer.c b/source/dnode/mnode/impl/src/mndConsumer.c
index 768fe45e3e1029b36a3147c32c597631d78c85b0..280f3b0eccb4c7d8b8b3929c24d470a05bbff399 100644
--- a/source/dnode/mnode/impl/src/mndConsumer.c
+++ b/source/dnode/mnode/impl/src/mndConsumer.c
@@ -618,6 +618,7 @@ int32_t mndProcessSubscribeReq(SRpcMsg *pMsg) {
 
     // set the update type
     pConsumerNew->updateType = CONSUMER_UPDATE__MODIFY;
+    taosArrayDestroy(pConsumerNew->assignedTopics);
     pConsumerNew->assignedTopics = taosArrayDup(pTopicList, topicNameDup);
 
     // all subscribed topics should re-balance.
@@ -647,6 +648,7 @@ int32_t mndProcessSubscribeReq(SRpcMsg *pMsg) {
 
     // set the update type
     pConsumerNew->updateType = CONSUMER_UPDATE__MODIFY;
+    taosArrayDestroy(pConsumerNew->assignedTopics);
     pConsumerNew->assignedTopics = taosArrayDup(pTopicList, topicNameDup);
 
     int32_t oldTopicNum = (pExistedConsumer->currentTopics)? taosArrayGetSize(pExistedConsumer->currentTopics):0;
diff --git a/source/util/src/thashutil.c b/source/util/src/thashutil.c
index 21b9359076078900196769046b54ff31fd88b0e4..f9c7eb1f5687440d5156d1999741ef777774aa67 100644
--- a/source/util/src/thashutil.c
+++ b/source/util/src/thashutil.c
@@ -50,11 +50,6 @@ uint32_t taosDJB2Hash(const char *key, uint32_t len) {
   return hash;
 }
 
-uint32_t xxHash(const char *key, uint32_t len) {
-  int32_t seed = 0xcc9e2d51;
-  return XXH32(key, len, seed);
-}
-
 uint32_t MurmurHash3_32(const char *key, uint32_t len) {
   const uint8_t *data = (const uint8_t *)key;
   const int32_t  nblocks = len >> 2u;