diff --git a/source/common/src/tmsgcb.c b/source/common/src/tmsgcb.c
index 1d15aac44d..e5cfe73cae 100644
--- a/source/common/src/tmsgcb.c
+++ b/source/common/src/tmsgcb.c
@@ -19,7 +19,11 @@
 
 static SMsgCb tsDefaultMsgCb;
 
-void tmsgSetDefaultMsgCb(const SMsgCb* pMsgCb) { tsDefaultMsgCb = *pMsgCb; }
+void tmsgSetDefaultMsgCb(const SMsgCb* pMsgCb) {
+  if (tsDefaultMsgCb.pWrapper == NULL) {
+    tsDefaultMsgCb = *pMsgCb;
+  }
+}
 
 int32_t tmsgPutToQueue(const SMsgCb* pMsgCb, EQueueType qtype, SRpcMsg* pReq) {
   PutToQueueFp fp = pMsgCb->queueFps[qtype];
diff --git a/source/dnode/mgmt/mgmt_mnode/src/mmWorker.c b/source/dnode/mgmt/mgmt_mnode/src/mmWorker.c
index 57b04b68f3..f55e02e50a 100644
--- a/source/dnode/mgmt/mgmt_mnode/src/mmWorker.c
+++ b/source/dnode/mgmt/mgmt_mnode/src/mmWorker.c
@@ -33,7 +33,7 @@ static void mmProcessQueue(SQueueInfo *pInfo, SNodeMsg *pMsg) {
   int32_t     code = -1;
   tmsg_t      msgType = pMsg->rpcMsg.msgType;
   bool        isRequest = msgType & 1U;
-  dTrace("msg:%p, get from mnode queue", pMsg);
+  dTrace("msg:%p, get from mnode queue, type:%s", pMsg, TMSG_INFO(msgType));
 
   switch (msgType) {
     case TDMT_DND_ALTER_MNODE: