diff --git a/src/mnode/src/mnodeSdb.c b/src/mnode/src/mnodeSdb.c
index 1d428ab9a21a3cf212cea03712b73065627ffbed..d8fc9aee5a680913ce52753214cac27b225033ab 100644
--- a/src/mnode/src/mnodeSdb.c
+++ b/src/mnode/src/mnodeSdb.c
@@ -32,6 +32,7 @@
 #include "mnodeSdb.h"
 
 #define SDB_TABLE_LEN 12
+#define SDB_SYNC_HACK 16
 
 typedef enum {
   SDB_ACTION_INSERT,
@@ -566,7 +567,7 @@ static int sdbWrite(void *param, void *data, int type) {
 
   // from app, oper is created
   if (pOper != NULL) {
-    sdbTrace("record from app is disposed, version:%" PRIu64 " code:%s", pHead->version, tstrerror(code));
+    sdbTrace("record from app is disposed, version:%" PRIu64 " result:%s", pHead->version, tstrerror(code));
     return code;
   }
   
@@ -628,10 +629,10 @@ int32_t sdbInsertRow(SSdbOper *pOper) {
     return TSDB_CODE_SUCCESS;
   }
 
-  int32_t size = sizeof(SSdbOper) + sizeof(SWalHead) + pTable->maxRowSize;
+  int32_t size = sizeof(SSdbOper) + sizeof(SWalHead) + pTable->maxRowSize + SDB_SYNC_HACK;
   SSdbOper *pNewOper = taosAllocateQitem(size);
   
-  SWalHead *pHead = (void *)pNewOper + sizeof(SSdbOper);
+  SWalHead *pHead = (void *)pNewOper + sizeof(SSdbOper) + SDB_SYNC_HACK;
   pHead->version = 0;
   pHead->len = pOper->rowSize;
   pHead->msgType = pTable->tableId * 10 + SDB_ACTION_INSERT;
@@ -692,10 +693,10 @@ int32_t sdbDeleteRow(SSdbOper *pOper) {
       return TSDB_CODE_MND_SDB_INVAID_KEY_TYPE;
   }
 
-  int32_t size = sizeof(SSdbOper) + sizeof(SWalHead) + keySize;
+  int32_t size = sizeof(SSdbOper) + sizeof(SWalHead) + keySize + SDB_SYNC_HACK;
   SSdbOper *pNewOper = taosAllocateQitem(size);
 
-  SWalHead *pHead = (void *)pNewOper + sizeof(SSdbOper);
+  SWalHead *pHead = (void *)pNewOper + sizeof(SSdbOper) + SDB_SYNC_HACK;
   pHead->version = 0;
   pHead->len = keySize;
   pHead->msgType = pTable->tableId * 10 + SDB_ACTION_DELETE;
@@ -738,10 +739,10 @@ int32_t sdbUpdateRow(SSdbOper *pOper) {
     return TSDB_CODE_SUCCESS;
   }
 
-  int32_t size = sizeof(SSdbOper) + sizeof(SWalHead) + pTable->maxRowSize;
+  int32_t size = sizeof(SSdbOper) + sizeof(SWalHead) + pTable->maxRowSize + SDB_SYNC_HACK;
   SSdbOper *pNewOper = taosAllocateQitem(size);
 
-  SWalHead *pHead = (void *)pNewOper + sizeof(SSdbOper);
+  SWalHead *pHead = (void *)pNewOper + sizeof(SSdbOper) + SDB_SYNC_HACK;
   pHead->version = 0;
   pHead->msgType = pTable->tableId * 10 + SDB_ACTION_UPDATE;
 
@@ -969,7 +970,7 @@ static void *sdbWorkerFp(void *param) {
       taosGetQitem(tsSdbWriteQall, &type, &item);
       if (type == TAOS_QTYPE_RPC) {
         pOper = (SSdbOper *)item;
-        pHead = (void *)pOper + sizeof(SSdbOper);
+        pHead = (void *)pOper + sizeof(SSdbOper) + SDB_SYNC_HACK;
       } else {
         pHead = (SWalHead *)item;
         pOper = NULL;
@@ -991,10 +992,10 @@ static void *sdbWorkerFp(void *param) {
       taosGetQitem(tsSdbWriteQall, &type, &item);
       if (type == TAOS_QTYPE_RPC) {
         pOper = (SSdbOper *)item;
-        if (pOper->cb) {
+        if (pOper != NULL && pOper->cb != NULL) {
           pOper->retCode = (*pOper->cb)(pOper->pMsg, pOper->retCode);
         }
-
+          
         if (pOper != NULL && pOper->pMsg != NULL) {
           sdbTrace("app:%p:%p, msg is processed, result:%s", pOper->pMsg->rpcMsg.ahandle, pOper->pMsg,
                    tstrerror(pOper->retCode));