diff --git a/include/libs/function/taosudf.h b/include/libs/function/taosudf.h
index 5703df87fa..c825574fa6 100644
--- a/include/libs/function/taosudf.h
+++ b/include/libs/function/taosudf.h
@@ -165,6 +165,8 @@ static FORCE_INLINE int32_t udfColEnsureCapacity(SUdfColumn *pColumn, int32_t ne
     if (tmp == NULL) {
       return TSDB_CODE_OUT_OF_MEMORY;
     }
+    uint32_t extend = BitmapLen(allocCapacity) - BitmapLen(data->rowsAlloc);
+    memset(tmp + BitmapLen(data->rowsAlloc), 0, extend);
     data->fixLenCol.nullBitmap = tmp;
     data->fixLenCol.nullBitmapLen = BitmapLen(allocCapacity);
     int32_t oldLen = BitmapLen(existedRows);
diff --git a/source/common/src/tdatablock.c b/source/common/src/tdatablock.c
index b2cf380f3b..f4d2ed01b0 100644
--- a/source/common/src/tdatablock.c
+++ b/source/common/src/tdatablock.c
@@ -221,6 +221,7 @@ static void doBitmapMerge(SColumnInfoData* pColumnInfoData, int32_t numOfRow1, c
   }
 
   uint8_t* p = (uint8_t*)pSource->nullbitmap;
+  pColumnInfoData->nullbitmap[BitmapLen(numOfRow1) - 1] &= (0B11111111 << shiftBits);  // clear remind bits
   pColumnInfoData->nullbitmap[BitmapLen(numOfRow1) - 1] |= (p[0] >> remindBits);  // copy remind bits
 
   if (BitmapLen(numOfRow1) == BitmapLen(total)) {
@@ -232,6 +233,7 @@ static void doBitmapMerge(SColumnInfoData* pColumnInfoData, int32_t numOfRow1, c
 
   uint8_t* start = (uint8_t*)&pColumnInfoData->nullbitmap[BitmapLen(numOfRow1)];
   int32_t  overCount = BitmapLen(total) - BitmapLen(numOfRow1);
+  memset(start, 0, overCount);
   while (i < len) {  // size limit of pSource->nullbitmap
     if (i >= 1) {
       start[i - 1] |= (p[i] >> remindBits);  // copy remind bits
@@ -309,9 +311,11 @@ int32_t colDataMergeCol(SColumnInfoData* pColumnInfoData, int32_t numOfRow1, int
       pColumnInfoData->pData = tmp;
       if (BitmapLen(numOfRow1) < BitmapLen(finalNumOfRows)) {
         char*    btmp = taosMemoryRealloc(pColumnInfoData->nullbitmap, BitmapLen(finalNumOfRows));
+        if (btmp == NULL) {
+          return TSDB_CODE_OUT_OF_MEMORY;
+        }
         uint32_t extend = BitmapLen(finalNumOfRows) - BitmapLen(numOfRow1);
         memset(btmp + BitmapLen(numOfRow1), 0, extend);
-
         pColumnInfoData->nullbitmap = btmp;
       }
 
diff --git a/source/dnode/mnode/impl/src/mndSubscribe.c b/source/dnode/mnode/impl/src/mndSubscribe.c
index 6a745a0a4f..49921c9a1a 100644
--- a/source/dnode/mnode/impl/src/mndSubscribe.c
+++ b/source/dnode/mnode/impl/src/mndSubscribe.c
@@ -671,7 +671,7 @@ static int32_t mndProcessRebalanceReq(SRpcMsg *pMsg) {
     // possibly no vg is changed
     // when each topic is re-balanced, issue an trans to save the results in sdb.
     if (mndPersistRebResult(pMnode, pMsg, &rebOutput) < 0) {
-      mError("mq re-balance persist output error, possibly vnode splitted or dropped");
+      mError("mq re-balance persist output error, possibly vnode splitted or dropped,msg:%s", terrstr());
     }
 
     taosArrayDestroy(rebOutput.newConsumers);
diff --git a/tests/parallel_test/cases.task b/tests/parallel_test/cases.task
index f6ba91a68c..dda4ec3e84 100644
--- a/tests/parallel_test/cases.task
+++ b/tests/parallel_test/cases.task
@@ -94,7 +94,7 @@
 ,,y,system-test,./pytest.sh python3 ./test.py -f 7-tmq/tmqDropStbCtb.py
 ,,y,system-test,./pytest.sh python3 ./test.py -f 7-tmq/tmqDropNtb-snapshot0.py
 ,,y,system-test,./pytest.sh python3 ./test.py -f 7-tmq/tmqDropNtb-snapshot1.py
-#,,y,system-test,./pytest.sh python3 ./test.py -f 7-tmq/tmqUdf.py
+,,y,system-test,./pytest.sh python3 ./test.py -f 7-tmq/tmqUdf.py
 ,,y,system-test,./pytest.sh python3 ./test.py -f 7-tmq/tmqUdf-multCtb-snapshot0.py
 ,,y,system-test,./pytest.sh python3 ./test.py -f 7-tmq/tmqUdf-multCtb-snapshot1.py
 ,,y,system-test,./pytest.sh python3 ./test.py -f 7-tmq/stbTagFilter-1ctb.py