diff --git a/include/dnode/mnode/sdb/sdb.h b/include/dnode/mnode/sdb/sdb.h
index 33f9dc5a1a..3ff86bea3e 100644
--- a/include/dnode/mnode/sdb/sdb.h
+++ b/include/dnode/mnode/sdb/sdb.h
@@ -181,6 +181,7 @@ typedef int32_t (*SdbDeleteFp)(SSdb *pSdb, void *pObj);
 typedef int32_t (*SdbDeployFp)(SMnode *pMnode);
 typedef SSdbRow *(*SdbDecodeFp)(SSdbRaw *pRaw);
 typedef SSdbRaw *(*SdbEncodeFp)(void *pObj);
+typedef bool (*sdbTraverseFp)(SMnode *pMnode, void *pObj, void *p1, void *p2, void *p3);
 
 typedef struct {
   ESdbType    sdbType;
@@ -279,7 +280,7 @@ void sdbRelease(SSdb *pSdb, void *pObj);
  *
  * @param pSdb The sdb object.
  * @param type The type of the table.
- * @param type The initial iterator of the table.
+ * @param pIter The initial iterator of the table.
  * @param pObj The object of the row just fetched.
  * @return void* The next iterator of the table.
  */
@@ -289,11 +290,22 @@ void *sdbFetch(SSdb *pSdb, ESdbType type, void *pIter, void **ppObj);
  * @brief Cancel a traversal
  *
  * @param pSdb The sdb object.
- * @param pIter The iterator of the table.
  * @param type The initial iterator of table.
  */
 void sdbCancelFetch(SSdb *pSdb, void *pIter);
 
+/**
+ * @brief Traverse a sdb
+ *
+ * @param pSdb The sdb object.
+ * @param type The initial iterator of table.
+ * @param fp The function pointer.
+ * @param p1 The callback param.
+ * @param p2 The callback param.
+ * @param p3 The callback param.
+ */
+void sdbTraverse(SSdb *pSdb, ESdbType type, sdbTraverseFp fp, void *p1, void *p2, void *p3);
+
 /**
  * @brief Get the number of rows in the table
  *
diff --git a/include/util/tlog.h b/include/util/tlog.h
index 5c91398cdc..a367243a46 100644
--- a/include/util/tlog.h
+++ b/include/util/tlog.h
@@ -37,7 +37,6 @@ extern int32_t mqttDebugFlag;
 extern int32_t monDebugFlag;
 extern int32_t uDebugFlag;
 extern int32_t rpcDebugFlag;
-extern int32_t odbcDebugFlag;
 extern int32_t qDebugFlag;
 extern int32_t wDebugFlag;
 extern int32_t sDebugFlag;
diff --git a/source/dnode/mnode/impl/inc/mndDef.h b/source/dnode/mnode/impl/inc/mndDef.h
index e66ffd4426..e26c0c5ae7 100644
--- a/source/dnode/mnode/impl/inc/mndDef.h
+++ b/source/dnode/mnode/impl/inc/mndDef.h
@@ -117,7 +117,7 @@ typedef struct {
   int64_t    rebootTime;
   int64_t    lastAccessTime;
   int32_t    accessTimes;
-  int16_t    numOfVnodes;
+  int32_t    numOfVnodes;
   int32_t    numOfSupportVnodes;
   int32_t    numOfCores;
   EDndReason offlineReason;
diff --git a/source/dnode/mnode/impl/src/mndDb.c b/source/dnode/mnode/impl/src/mndDb.c
index d05e301024..f9199f9eed 100644
--- a/source/dnode/mnode/impl/src/mndDb.c
+++ b/source/dnode/mnode/impl/src/mndDb.c
@@ -549,7 +549,7 @@ static int32_t mndSetUpdateDbRedoLogs(SMnode *pMnode, STrans *pTrans, SDbObj *pO
   return 0;
 }
 
-static int32_t mndSetUpdateDbCommitLogs(SMnode *pMnode, STrans *pTrans, SDbObj *pOldDb, SDbObj *pNewDb) { 
+static int32_t mndSetUpdateDbCommitLogs(SMnode *pMnode, STrans *pTrans, SDbObj *pOldDb, SDbObj *pNewDb) {
   SSdbRaw *pCommitRaw = mndDbActionEncode(pNewDb);
   if (pCommitRaw == NULL) return -1;
   if (mndTransAppendCommitlog(pTrans, pCommitRaw) != 0) return -1;
@@ -725,7 +725,7 @@ static int32_t mndSetDropDbCommitLogs(SMnode *pMnode, STrans *pTrans, SDbObj *pD
 static int32_t mndBuildDropVgroupAction(SMnode *pMnode, STrans *pTrans, SDbObj *pDb, SVgObj *pVgroup) {
   for (int32_t vn = 0; vn < pVgroup->replica; ++vn) {
     STransAction action = {0};
-    SVnodeGid *  pVgid = pVgroup->vnodeGid + vn;
+    SVnodeGid   *pVgid = pVgroup->vnodeGid + vn;
 
     SDnodeObj *pDnode = mndAcquireDnode(pMnode, pVgid->dnodeId);
     if (pDnode == NULL) return -1;
diff --git a/source/dnode/mnode/impl/src/mndDnode.c b/source/dnode/mnode/impl/src/mndDnode.c
index ca20ba61a1..1c7f8544e9 100644
--- a/source/dnode/mnode/impl/src/mndDnode.c
+++ b/source/dnode/mnode/impl/src/mndDnode.c
@@ -196,6 +196,8 @@ static SDnodeObj *mndAcquireDnodeByEp(SMnode *pMnode, char *pEpStr) {
       sdbCancelFetch(pSdb, pIter);
       return pDnode;
     }
+
+    sdbRelease(pSdb, pDnode);
   }
 
   return NULL;
@@ -419,10 +421,9 @@ static int32_t mndCreateDnode(SMnode *pMnode, SMnodeMsg *pMsg, SCreateDnodeMsg *
 static int32_t mndProcessCreateDnodeMsg(SMnodeMsg *pMsg) {
   SMnode          *pMnode = pMsg->pMnode;
   SCreateDnodeMsg *pCreate = pMsg->rpcMsg.pCont;
-
+  pCreate->port = htonl(pCreate->port);
   mDebug("dnode:%s:%d, start to create", pCreate->fqdn, pCreate->port);
 
-  pCreate->port = htonl(pCreate->port);
   if (pCreate->fqdn[0] == 0 || pCreate->port <= 0 || pCreate->port > UINT16_MAX) {
     terrno = TSDB_CODE_MND_INVALID_DNODE_EP;
     mError("dnode:%s:%d, failed to create since %s", pCreate->fqdn, pCreate->port, terrstr());
diff --git a/source/dnode/mnode/impl/src/mndMnode.c b/source/dnode/mnode/impl/src/mndMnode.c
index b76d72d79c..ad3d5e1cf6 100644
--- a/source/dnode/mnode/impl/src/mndMnode.c
+++ b/source/dnode/mnode/impl/src/mndMnode.c
@@ -219,6 +219,7 @@ void mndGetMnodeEpSet(SMnode *pMnode, SEpSet *pEpSet) {
     }
 
     pEpSet->numOfEps++;
+    sdbRelease(pSdb, pObj);
   }
 }
 
diff --git a/source/dnode/mnode/impl/src/mndTrans.c b/source/dnode/mnode/impl/src/mndTrans.c
index 9263fca695..cf434dda39 100644
--- a/source/dnode/mnode/impl/src/mndTrans.c
+++ b/source/dnode/mnode/impl/src/mndTrans.c
@@ -79,17 +79,17 @@ static SSdbRaw *mndTransActionEncode(STrans *pTrans) {
 
   for (int32_t i = 0; i < redoLogNum; ++i) {
     SSdbRaw *pTmp = taosArrayGetP(pTrans->redoLogs, i);
-    rawDataLen += sdbGetRawTotalSize(pTmp);
+    rawDataLen += (sdbGetRawTotalSize(pTmp) + 4);
   }
 
   for (int32_t i = 0; i < undoLogNum; ++i) {
     SSdbRaw *pTmp = taosArrayGetP(pTrans->undoLogs, i);
-    rawDataLen += sdbGetRawTotalSize(pTmp);
+    rawDataLen += (sdbGetRawTotalSize(pTmp) + 4);
   }
 
   for (int32_t i = 0; i < commitLogNum; ++i) {
     SSdbRaw *pTmp = taosArrayGetP(pTrans->commitLogs, i);
-    rawDataLen += sdbGetRawTotalSize(pTmp);
+    rawDataLen += (sdbGetRawTotalSize(pTmp) + 4);
   }
 
   for (int32_t i = 0; i < redoActionNum; ++i) {
@@ -437,7 +437,7 @@ int32_t mndTransAppendUndoAction(STrans *pTrans, STransAction *pAction) {
 static int32_t mndTransSync(SMnode *pMnode, STrans *pTrans) {
   SSdbRaw *pRaw = mndTransActionEncode(pTrans);
   if (pRaw == NULL) {
-    mError("trans:%d, failed to decode trans since %s", pTrans->id, terrstr());
+    mError("trans:%d, failed to encode while sync trans since %s", pTrans->id, terrstr());
     return -1;
   }
   sdbSetRawStatus(pRaw, SDB_STATUS_READY);
@@ -835,7 +835,7 @@ static bool mndTransPerfromFinishedStage(SMnode *pMnode, STrans *pTrans) {
 
   SSdbRaw *pRaw = mndTransActionEncode(pTrans);
   if (pRaw == NULL) {
-    mError("trans:%d, failed to decode trans since %s", pTrans->id, terrstr());
+    mError("trans:%d, failed to encode while finish trans since %s", pTrans->id, terrstr());
   }
   sdbSetRawStatus(pRaw, SDB_STATUS_DROPPED);
 
diff --git a/source/dnode/mnode/impl/src/mndVgroup.c b/source/dnode/mnode/impl/src/mndVgroup.c
index 1b0026cd13..41de70283f 100644
--- a/source/dnode/mnode/impl/src/mndVgroup.c
+++ b/source/dnode/mnode/impl/src/mndVgroup.c
@@ -238,39 +238,48 @@ SDropVnodeMsg *mndBuildDropVnodeMsg(SMnode *pMnode, SDnodeObj *pDnode, SDbObj *p
   return pDrop;
 }
 
+static bool mndResetDnodesArrayFp(SMnode *pMnode, void *pObj, void *p1, void *p2, void *p3) {
+  SDnodeObj *pDnode = pObj;
+  pDnode->numOfVnodes = 0;
+  return true;
+}
+
+static bool mndBuildDnodesArrayFp(SMnode *pMnode, void *pObj, void *p1, void *p2, void *p3) {
+  SDnodeObj *pDnode = pObj;
+  SArray    *pArray = p1;
+
+  pDnode->numOfVnodes = mndGetVnodesNum(pMnode, pDnode->id);
+
+  int64_t curMs = taosGetTimestampMs();
+  bool    online = mndIsDnodeOnline(pMnode, pDnode, curMs);
+  if (online && pDnode->numOfSupportVnodes > 0) {
+    taosArrayPush(pArray, pDnode);
+  }
+
+  bool isMnode = mndIsMnode(pMnode, pDnode->id);
+
+  mDebug("dnode:%d, vnodes:%d supportVnodes:%d isMnode:%d online:%d", pDnode->id, pDnode->numOfVnodes,
+         pDnode->numOfSupportVnodes, isMnode, online);
+
+  if (isMnode) {
+    pDnode->numOfVnodes++;
+  }
+
+  return true;
+}
+
 static SArray *mndBuildDnodesArray(SMnode *pMnode) {
   SSdb   *pSdb = pMnode->pSdb;
   int32_t numOfDnodes = mndGetDnodeSize(pMnode);
+
   SArray *pArray = taosArrayInit(numOfDnodes, sizeof(SDnodeObj));
   if (pArray == NULL) {
     terrno = TSDB_CODE_OUT_OF_MEMORY;
     return NULL;
   }
 
-  void *pIter = NULL;
-  while (1) {
-    SDnodeObj *pDnode = NULL;
-    pIter = sdbFetch(pSdb, SDB_DNODE, pIter, (void **)&pDnode);
-    if (pIter == NULL) break;
-
-    int32_t numOfVnodes = mndGetVnodesNum(pMnode, pDnode->id);
-
-    bool isMnode = mndIsMnode(pMnode, pDnode->id);
-    if (isMnode) {
-      pDnode->numOfVnodes++;
-    }
-
-    int64_t curMs = taosGetTimestampMs();
-    bool    online = mndIsDnodeOnline(pMnode, pDnode, curMs);
-    if (online) {
-      taosArrayPush(pArray, pDnode);
-    }
-
-    mDebug("dnode:%d, vnodes:%d supportVnodes:%d isMnode:%d online:%d", pDnode->id, numOfVnodes,
-           pDnode->numOfSupportVnodes, isMnode, online);
-    sdbRelease(pSdb, pDnode);
-  }
-
+  sdbTraverse(pSdb, SDB_DNODE, mndResetDnodesArrayFp, NULL, NULL, NULL);
+  sdbTraverse(pSdb, SDB_DNODE, mndBuildDnodesArrayFp, pArray, NULL, NULL);
   return pArray;
 }
 
@@ -302,7 +311,7 @@ static int32_t mndGetAvailableDnode(SMnode *pMnode, SVgObj *pVgroup, SArray *pAr
       pVgid->role = TAOS_SYNC_STATE_FOLLOWER;
     }
 
-    mDebug("db:%s, vgId:%d, vindex:%d dnodeId:%d is alloced", pVgroup->dbName, pVgroup->vgId, v, pVgid->dnodeId);
+    mDebug("db:%s, vgId:%d, vn:%d dnode:%d is alloced", pVgroup->dbName, pVgroup->vgId, v, pVgid->dnodeId);
     pDnode->numOfVnodes++;
   }
 
@@ -412,6 +421,20 @@ static int32_t mndProcessSyncVnodeRsp(SMnodeMsg *pMsg) { return 0; }
 
 static int32_t mndProcessCompactVnodeRsp(SMnodeMsg *pMsg) { return 0; }
 
+static bool mndGetVgroupMaxReplicaFp(SMnode *pMnode, void *pObj, void *p1, void *p2, void *p3) {
+  SVgObj  *pVgroup = pObj;
+  int64_t  uid = *(int64_t *)p1;
+  int8_t  *pReplica = p2;
+  int32_t *pNumOfVgroups = p3;
+
+  if (pVgroup->dbUid == uid) {
+    *pReplica = MAX(*pReplica, pVgroup->replica);
+    (*pNumOfVgroups)++;
+  }
+
+  return true;
+}
+
 static int32_t mndGetVgroupMaxReplica(SMnode *pMnode, char *dbName, int8_t *pReplica, int32_t *pNumOfVgroups) {
   SSdb   *pSdb = pMnode->pSdb;
   SDbObj *pDb = mndAcquireDb(pMnode, dbName);
@@ -420,25 +443,10 @@ static int32_t mndGetVgroupMaxReplica(SMnode *pMnode, char *dbName, int8_t *pRep
     return -1;
   }
 
-  int8_t  replica = 1;
-  int32_t numOfVgroups = 0;
-
-  void *pIter = NULL;
-  while (1) {
-    SVgObj *pVgroup = NULL;
-    pIter = sdbFetch(pSdb, SDB_VGROUP, pIter, (void **)&pVgroup);
-    if (pIter == NULL) break;
-
-    if (pVgroup->dbUid == pDb->uid) {
-      replica = MAX(replica, pVgroup->replica);
-      numOfVgroups++;
-    }
-
-    sdbRelease(pSdb, pVgroup);
-  }
-
-  *pReplica = replica;
-  *pNumOfVgroups = numOfVgroups;
+  *pReplica = 1;
+  *pNumOfVgroups = 0;
+  sdbTraverse(pSdb, SDB_VGROUP, mndGetVgroupMaxReplicaFp, &pDb->uid, pReplica, pNumOfVgroups);
+  mndReleaseDb(pMnode, pDb);
   return 0;
 }
 
@@ -540,25 +548,23 @@ static void mndCancelGetNextVgroup(SMnode *pMnode, void *pIter) {
   sdbCancelFetch(pSdb, pIter);
 }
 
-int32_t mndGetVnodesNum(SMnode *pMnode, int32_t dnodeId) {
-  SSdb   *pSdb = pMnode->pSdb;
-  int32_t numOfVnodes = 0;
-  void   *pIter = NULL;
+static bool mndGetVnodesNumFp(SMnode *pMnode, void *pObj, void *p1, void *p2, void *p3) {
+  SVgObj  *pVgroup = pObj;
+  int32_t  dnodeId = *(int32_t *)p1;
+  int32_t *pNumOfVnodes = (int32_t *)p2;
 
-  while (1) {
-    SVgObj *pVgroup = NULL;
-    pIter = sdbFetch(pSdb, SDB_VGROUP, pIter, (void **)&pVgroup);
-    if (pIter == NULL) break;
-
-    for (int32_t v = 0; v < pVgroup->replica; ++v) {
-      if (pVgroup->vnodeGid[v].dnodeId == dnodeId) {
-        numOfVnodes++;
-      }
+  for (int32_t v = 0; v < pVgroup->replica; ++v) {
+    if (pVgroup->vnodeGid[v].dnodeId == dnodeId) {
+      (*pNumOfVnodes)++;
     }
-
-    sdbRelease(pSdb, pVgroup);
   }
 
+  return true;
+}
+
+int32_t mndGetVnodesNum(SMnode *pMnode, int32_t dnodeId) {
+  int32_t numOfVnodes = 0;
+  sdbTraverse(pMnode->pSdb, SDB_VGROUP, mndGetVnodesNumFp, &dnodeId, &numOfVnodes, NULL);
   return numOfVnodes;
 }
 
diff --git a/source/dnode/mnode/sdb/src/sdbHash.c b/source/dnode/mnode/sdb/src/sdbHash.c
index 06c2563910..0388fa99f5 100644
--- a/source/dnode/mnode/sdb/src/sdbHash.c
+++ b/source/dnode/mnode/sdb/src/sdbHash.c
@@ -336,6 +336,30 @@ void sdbCancelFetch(SSdb *pSdb, void *pIter) {
   taosRUnLockLatch(pLock);
 }
 
+void sdbTraverse(SSdb *pSdb, ESdbType type, sdbTraverseFp fp, void *p1, void *p2, void *p3) {
+  SHashObj *hash = sdbGetHash(pSdb, type);
+  if (hash == NULL) return;
+
+  SRWLatch *pLock = &pSdb->locks[type];
+  taosRLockLatch(pLock);
+
+  SSdbRow **ppRow = taosHashIterate(hash, NULL);
+  while (ppRow != NULL) {
+    SSdbRow *pRow = *ppRow;
+    if (pRow->status == SDB_STATUS_READY) {
+      bool isContinue = (*fp)(pSdb->pMnode, pRow->pObj, p1, p2, p3);
+      if (!isContinue) {
+        taosHashCancelIterate(hash, ppRow);
+        break;
+      }
+    }
+
+    ppRow = taosHashIterate(hash, ppRow);
+  }
+
+  taosRUnLockLatch(pLock);
+}
+
 int32_t sdbGetSize(SSdb *pSdb, ESdbType type) {
   SHashObj *hash = sdbGetHash(pSdb, type);
   if (hash == NULL) return 0;