diff --git a/include/libs/stream/tstream.h b/include/libs/stream/tstream.h
index 8f5d6c38f3..8e7dd0bb0d 100644
--- a/include/libs/stream/tstream.h
+++ b/include/libs/stream/tstream.h
@@ -372,6 +372,7 @@ typedef struct {
   int32_t upstreamChildId;
   int32_t upstreamNodeId;
   int32_t blockNum;
+  int64_t totalLen;
   SArray* dataLen;  // SArray<int32_t>
   SArray* data;     // SArray<SRetrieveTableRsp*>
 } SStreamDispatchReq;
@@ -527,7 +528,7 @@ void tDeleteStreamDispatchReq(SStreamDispatchReq* pReq);
 int32_t streamSetupTrigger(SStreamTask* pTask);
 
 int32_t streamProcessRunReq(SStreamTask* pTask);
-int32_t streamProcessDispatchReq(SStreamTask* pTask, SStreamDispatchReq* pReq, SRpcMsg* pMsg, bool exec);
+int32_t streamProcessDispatchMsg(SStreamTask* pTask, SStreamDispatchReq* pReq, SRpcMsg* pMsg, bool exec);
 int32_t streamProcessDispatchRsp(SStreamTask* pTask, SStreamDispatchRsp* pRsp, int32_t code);
 
 int32_t streamProcessRetrieveReq(SStreamTask* pTask, SStreamRetrieveReq* pReq, SRpcMsg* pMsg);
@@ -536,7 +537,7 @@ int32_t streamProcessRetrieveReq(SStreamTask* pTask, SStreamRetrieveReq* pReq, S
 void    streamTaskInputFail(SStreamTask* pTask);
 int32_t streamTryExec(SStreamTask* pTask);
 int32_t streamSchedExec(SStreamTask* pTask);
-int32_t streamTaskOutput(SStreamTask* pTask, SStreamDataBlock* pBlock);
+int32_t streamTaskOutputResultBlock(SStreamTask* pTask, SStreamDataBlock* pBlock);
 bool    streamTaskShouldStop(const SStreamStatus* pStatus);
 bool    streamTaskShouldPause(const SStreamStatus* pStatus);
 
diff --git a/source/common/src/tdatablock.c b/source/common/src/tdatablock.c
index 2a125a5831..42424b6436 100644
--- a/source/common/src/tdatablock.c
+++ b/source/common/src/tdatablock.c
@@ -2513,9 +2513,6 @@ int32_t blockEncode(const SSDataBlock* pBlock, char* data, int32_t numOfCols) {
   *actualLen = dataLen;
   *groupId = pBlock->info.id.groupId;
   ASSERT(dataLen > 0);
-
-  uDebug("build data block, actualLen:%d, rows:%d, cols:%d", dataLen, *rows, *cols);
-
   return dataLen;
 }
 
diff --git a/source/dnode/snode/src/snode.c b/source/dnode/snode/src/snode.c
index 2ff338242f..e9225f3d6e 100644
--- a/source/dnode/snode/src/snode.c
+++ b/source/dnode/snode/src/snode.c
@@ -43,7 +43,7 @@ void sndEnqueueStreamDispatch(SSnode *pSnode, SRpcMsg *pMsg) {
         .info = pMsg->info,
         .code = 0,
     };
-    streamProcessDispatchReq(pTask, &req, &rsp, false);
+    streamProcessDispatchMsg(pTask, &req, &rsp, false);
     streamMetaReleaseTask(pSnode->pMeta, pTask);
     rpcFreeCont(pMsg->pCont);
     taosFreeQitem(pMsg);
@@ -203,17 +203,13 @@ int32_t sndProcessTaskDispatchReq(SSnode *pSnode, SRpcMsg *pMsg, bool exec) {
 
   SStreamTask *pTask = streamMetaAcquireTask(pSnode->pMeta, taskId);
   if (pTask) {
-    SRpcMsg rsp = {
-        .info = pMsg->info,
-        .code = 0,
-    };
-    streamProcessDispatchReq(pTask, &req, &rsp, exec);
+    SRpcMsg rsp = { .info = pMsg->info, .code = 0 };
+    streamProcessDispatchMsg(pTask, &req, &rsp, exec);
     streamMetaReleaseTask(pSnode->pMeta, pTask);
     return 0;
   } else {
     return -1;
   }
-  return 0;
 }
 
 int32_t sndProcessTaskRetrieveReq(SSnode *pSnode, SRpcMsg *pMsg) {
@@ -227,11 +223,9 @@ int32_t sndProcessTaskRetrieveReq(SSnode *pSnode, SRpcMsg *pMsg) {
   tDecoderClear(&decoder);
   int32_t      taskId = req.dstTaskId;
   SStreamTask *pTask = streamMetaAcquireTask(pSnode->pMeta, taskId);
+
   if (pTask) {
-    SRpcMsg rsp = {
-        .info = pMsg->info,
-        .code = 0,
-    };
+    SRpcMsg rsp = { .info = pMsg->info, .code = 0};
     streamProcessRetrieveReq(pTask, &req, &rsp);
     streamMetaReleaseTask(pSnode->pMeta, pTask);
     tDeleteStreamRetrieveReq(&req);
diff --git a/source/dnode/vnode/inc/vnode.h b/source/dnode/vnode/inc/vnode.h
index da5d6f8b3c..18fa893fa4 100644
--- a/source/dnode/vnode/inc/vnode.h
+++ b/source/dnode/vnode/inc/vnode.h
@@ -198,6 +198,7 @@ void        *tsdbGetIdx(SMeta *pMeta);
 void        *tsdbGetIvtIdx(SMeta *pMeta);
 uint64_t     tsdbGetReaderMaxVersion(STsdbReader *pReader);
 void         tsdbReaderSetCloseFlag(STsdbReader *pReader);
+int64_t      tsdbGetLastTimestamp(SVnode* pVnode, void* pTableList, int32_t numOfTables, const char* pIdStr);
 
 int32_t tsdbReuseCacherowsReader(void* pReader, void* pTableIdList, int32_t numOfTables);
 int32_t tsdbCacherowsReaderOpen(void *pVnode, int32_t type, void *pTableIdList, int32_t numOfTables, int32_t numOfCols,
diff --git a/source/dnode/vnode/src/tq/tq.c b/source/dnode/vnode/src/tq/tq.c
index a8c2a09319..74361ec319 100644
--- a/source/dnode/vnode/src/tq/tq.c
+++ b/source/dnode/vnode/src/tq/tq.c
@@ -760,6 +760,7 @@ void freePtr(void *ptr) {
 
 int32_t tqExpandTask(STQ* pTq, SStreamTask* pTask, int64_t ver) {
   int32_t vgId = TD_VID(pTq->pVnode);
+
   pTask->id.idStr = createStreamTaskIdStr(pTask->id.streamId, pTask->id.taskId);
   pTask->refCnt = 1;
   pTask->status.schedStatus = TASK_SCHED_STATUS__INACTIVE;
@@ -837,7 +838,7 @@ int32_t tqExpandTask(STQ* pTq, SStreamTask* pTask, int64_t ver) {
   }
 
   if (pTask->taskLevel == TASK_LEVEL__SOURCE) {
-    SWalFilterCond cond = {.deleteMsg = 1};
+    SWalFilterCond cond = {.deleteMsg = 1};  // delete msg also extract from wal files
     pTask->exec.pWalReader = walOpenReader(pTq->pVnode->pWal, &cond);
   }
 
@@ -852,14 +853,17 @@ int32_t tqExpandTask(STQ* pTq, SStreamTask* pTask, int64_t ver) {
 }
 
 int32_t tqProcessStreamTaskCheckReq(STQ* pTq, SRpcMsg* pMsg) {
-  char*               msgStr = pMsg->pCont;
-  char*               msgBody = POINTER_SHIFT(msgStr, sizeof(SMsgHead));
-  int32_t             msgLen = pMsg->contLen - sizeof(SMsgHead);
+  char*   msgStr = pMsg->pCont;
+  char*   msgBody = POINTER_SHIFT(msgStr, sizeof(SMsgHead));
+  int32_t msgLen = pMsg->contLen - sizeof(SMsgHead);
+
   SStreamTaskCheckReq req;
   SDecoder            decoder;
+
   tDecoderInit(&decoder, (uint8_t*)msgBody, msgLen);
   tDecodeSStreamTaskCheckReq(&decoder, &req);
   tDecoderClear(&decoder);
+
   int32_t             taskId = req.downstreamTaskId;
   SStreamTaskCheckRsp rsp = {
       .reqId = req.reqId,
@@ -873,18 +877,18 @@ int32_t tqProcessStreamTaskCheckReq(STQ* pTq, SRpcMsg* pMsg) {
 
   SStreamTask* pTask = streamMetaAcquireTask(pTq->pStreamMeta, taskId);
 
-  if (pTask) {
+  if (pTask != NULL) {
     rsp.status = streamTaskCheckStatus(pTask);
     streamMetaReleaseTask(pTq->pStreamMeta, pTask);
 
-    tqDebug("tq recv task check req(reqId:0x%" PRIx64
+    tqDebug("s-task:%s recv task check req(reqId:0x%" PRIx64
             ") %d at node %d task status:%d, check req from task %d at node %d, rsp status %d",
-            rsp.reqId, rsp.downstreamTaskId, rsp.downstreamNodeId, pTask->status.taskStatus, rsp.upstreamTaskId,
-            rsp.upstreamNodeId, rsp.status);
+            pTask->id.idStr, rsp.reqId, rsp.downstreamTaskId, rsp.downstreamNodeId, pTask->status.taskStatus,
+            rsp.upstreamTaskId, rsp.upstreamNodeId, rsp.status);
   } else {
     rsp.status = 0;
-    tqDebug("tq recv task check(taskId:%d not built yet) req(reqId:0x%" PRIx64
-            ") %d at node %d, check req from task %d at node %d, rsp status %d",
+    tqDebug("tq recv task check(taskId:0x%x not built yet) req(reqId:0x%" PRIx64
+            ") %d at node %d, check req from task:0x%x at node %d, rsp status %d",
             taskId, rsp.reqId, rsp.downstreamTaskId, rsp.downstreamNodeId, rsp.upstreamTaskId, rsp.upstreamNodeId,
             rsp.status);
   }
@@ -892,9 +896,10 @@ int32_t tqProcessStreamTaskCheckReq(STQ* pTq, SRpcMsg* pMsg) {
   SEncoder encoder;
   int32_t  code;
   int32_t  len;
+
   tEncodeSize(tEncodeSStreamTaskCheckRsp, &rsp, len, code);
   if (code < 0) {
-    tqError("unable to encode rsp %d", __LINE__);
+    tqError("vgId:%d failed to encode task check rsp, task:0x%x", pTq->pStreamMeta->vgId, taskId);
     return -1;
   }
 
@@ -907,6 +912,7 @@ int32_t tqProcessStreamTaskCheckReq(STQ* pTq, SRpcMsg* pMsg) {
   tEncoderClear(&encoder);
 
   SRpcMsg rspMsg = {.code = 0, .pCont = buf, .contLen = sizeof(SMsgHead) + len, .info = pMsg->info};
+
   tmsgSendRsp(&rspMsg);
   return 0;
 }
@@ -918,17 +924,20 @@ int32_t tqProcessStreamTaskCheckRsp(STQ* pTq, int64_t sversion, char* msg, int32
   SDecoder decoder;
   tDecoderInit(&decoder, (uint8_t*)msg, msgLen);
   code = tDecodeSStreamTaskCheckRsp(&decoder, &rsp);
+
   if (code < 0) {
     tDecoderClear(&decoder);
     return -1;
   }
 
   tDecoderClear(&decoder);
-  tqDebug("tq recv task check rsp(reqId:0x%" PRIx64 ") %d at node %d check req from task %d at node %d, status %d",
+  tqDebug("tq recv task check rsp(reqId:0x%" PRIx64 ") %d at node %d check req from task:0x%x at node %d, status %d",
           rsp.reqId, rsp.downstreamTaskId, rsp.downstreamNodeId, rsp.upstreamTaskId, rsp.upstreamNodeId, rsp.status);
 
   SStreamTask* pTask = streamMetaAcquireTask(pTq->pStreamMeta, rsp.upstreamTaskId);
   if (pTask == NULL) {
+    tqError("tq failed to locate the stream task:0x%x vgId:%d, it may have been destroyed", rsp.upstreamTaskId,
+            pTq->pStreamMeta->vgId);
     return -1;
   }
 
@@ -948,6 +957,8 @@ int32_t tqProcessTaskDeployReq(STQ* pTq, int64_t sversion, char* msg, int32_t ms
   // 1.deserialize msg and build task
   SStreamTask* pTask = taosMemoryCalloc(1, sizeof(SStreamTask));
   if (pTask == NULL) {
+    terrno = TSDB_CODE_OUT_OF_MEMORY;
+    tqError("vgId:%d failed to create stream task due to out of memory, alloc size:%d", vgId, (int32_t) sizeof(SStreamTask));
     return -1;
   }
 
@@ -965,9 +976,9 @@ int32_t tqProcessTaskDeployReq(STQ* pTq, int64_t sversion, char* msg, int32_t ms
   // 2.save task, use the newest commit version as the initial start version of stream task.
   taosWLockLatch(&pTq->pStreamMeta->lock);
   code = streamMetaAddDeployedTask(pTq->pStreamMeta, sversion, pTask);
+  int32_t numOfTasks = streamMetaGetNumOfTasks(pTq->pStreamMeta);
   if (code < 0) {
-    tqError("vgId:%d failed to add s-task:%s, total:%d", vgId, pTask->id.idStr,
-            streamMetaGetNumOfTasks(pTq->pStreamMeta));
+    tqError("vgId:%d failed to add s-task:%s, total:%d", vgId, pTask->id.idStr, numOfTasks);
     taosWUnLockLatch(&pTq->pStreamMeta->lock);
     return -1;
   }
@@ -980,7 +991,7 @@ int32_t tqProcessTaskDeployReq(STQ* pTq, int64_t sversion, char* msg, int32_t ms
   }
 
   tqDebug("vgId:%d s-task:%s is deployed and add meta from mnd, status:%d, total:%d", vgId, pTask->id.idStr,
-          pTask->status.taskStatus, streamMetaGetNumOfTasks(pTq->pStreamMeta));
+          pTask->status.taskStatus, numOfTasks);
   return 0;
 }
 
@@ -1229,15 +1240,17 @@ int32_t tqProcessTaskDispatchReq(STQ* pTq, SRpcMsg* pMsg, bool exec) {
   char*              msgStr = pMsg->pCont;
   char*              msgBody = POINTER_SHIFT(msgStr, sizeof(SMsgHead));
   int32_t            msgLen = pMsg->contLen - sizeof(SMsgHead);
-  SStreamDispatchReq req;
-  SDecoder           decoder;
+
+  SStreamDispatchReq req = {0};
+
+  SDecoder decoder;
   tDecoderInit(&decoder, (uint8_t*)msgBody, msgLen);
   tDecodeStreamDispatchReq(&decoder, &req);
 
   SStreamTask* pTask = streamMetaAcquireTask(pTq->pStreamMeta, req.taskId);
   if (pTask) {
     SRpcMsg rsp = {.info = pMsg->info, .code = 0};
-    streamProcessDispatchReq(pTask, &req, &rsp, exec);
+    streamProcessDispatchMsg(pTask, &req, &rsp, exec);
     streamMetaReleaseTask(pTq->pStreamMeta, pTask);
     return 0;
   } else {
@@ -1356,7 +1369,7 @@ int32_t vnodeEnqueueStreamMsg(SVnode* pVnode, SRpcMsg* pMsg) {
   SStreamTask* pTask = streamMetaAcquireTask(pTq->pStreamMeta, taskId);
   if (pTask) {
     SRpcMsg rsp = {.info = pMsg->info, .code = 0};
-    streamProcessDispatchReq(pTask, &req, &rsp, false);
+    streamProcessDispatchMsg(pTask, &req, &rsp, false);
     streamMetaReleaseTask(pTq->pStreamMeta, pTask);
     rpcFreeCont(pMsg->pCont);
     taosFreeQitem(pMsg);
diff --git a/source/dnode/vnode/src/tq/tqRestore.c b/source/dnode/vnode/src/tq/tqRestore.c
index 9acf2454af..ff9f95d5fa 100644
--- a/source/dnode/vnode/src/tq/tqRestore.c
+++ b/source/dnode/vnode/src/tq/tqRestore.c
@@ -119,7 +119,7 @@ int32_t createStreamTaskRunReq(SStreamMeta* pStreamMeta, bool* pScanIdle) {
 
     int32_t status = pTask->status.taskStatus;
     if (pTask->taskLevel != TASK_LEVEL__SOURCE) {
-      tqDebug("s-task:%s level:%d not source task, no need to start", pTask->id.idStr, pTask->taskLevel);
+//      tqTrace("s-task:%s level:%d not source task, no need to start", pTask->id.idStr, pTask->taskLevel);
       streamMetaReleaseTask(pStreamMeta, pTask);
       continue;
     }
@@ -132,7 +132,7 @@ int32_t createStreamTaskRunReq(SStreamMeta* pStreamMeta, bool* pScanIdle) {
     }
 
     if (tInputQueueIsFull(pTask)) {
-      tqDebug("s-task:%s input queue is full, do nothing", pTask->id.idStr);
+      tqTrace("s-task:%s input queue is full, do nothing", pTask->id.idStr);
       streamMetaReleaseTask(pStreamMeta, pTask);
       continue;
     }
diff --git a/source/dnode/vnode/src/tsdb/tsdbRead.c b/source/dnode/vnode/src/tsdb/tsdbRead.c
index 36b18ce9f4..cde2672541 100644
--- a/source/dnode/vnode/src/tsdb/tsdbRead.c
+++ b/source/dnode/vnode/src/tsdb/tsdbRead.c
@@ -5506,3 +5506,58 @@ void tsdbReaderSetId(STsdbReader* pReader, const char* idstr) {
 }
 
 void tsdbReaderSetCloseFlag(STsdbReader* pReader) { pReader->code = TSDB_CODE_TSC_QUERY_CANCELLED; }
+
+/*-------------todo:refactor the implementation of those APIs in this file to seperate the API into two files------*/
+// opt perf, do NOT create so many readers
+int64_t tsdbGetLastTimestamp(SVnode* pVnode, void* pTableList, int32_t numOfTables, const char* pIdStr) {
+  SQueryTableDataCond cond = {.type = TIMEWINDOW_RANGE_CONTAINED, .numOfCols = 1, .order = TSDB_ORDER_DESC,
+                              .startVersion = -1, .endVersion = -1};
+  cond.twindows.skey = INT64_MIN;
+  cond.twindows.ekey = INT64_MAX;
+
+  cond.colList = taosMemoryCalloc(1, sizeof(SColumnInfo));
+  cond.pSlotList = taosMemoryMalloc(sizeof(int32_t) * cond.numOfCols);
+  if (cond.colList == NULL || cond.pSlotList == NULL) {
+    // todo
+  }
+
+  cond.colList[0].colId = 1;
+  cond.colList[0].slotId = 0;
+  cond.colList[0].type = TSDB_DATA_TYPE_TIMESTAMP;
+
+  cond.pSlotList[0] = 0;
+
+  STableKeyInfo* pTableKeyInfo = pTableList;
+  STsdbReader* pReader = NULL;
+  SSDataBlock* pBlock = createDataBlock();
+
+  SColumnInfoData data = {0};
+  data.info = (SColumnInfo) {.type = TSDB_DATA_TYPE_TIMESTAMP, .colId = 1, .bytes = TSDB_KEYSIZE};
+  blockDataAppendColInfo(pBlock, &data);
+
+  int64_t key = INT64_MIN;
+
+  for(int32_t i = 0; i < numOfTables; ++i) {
+    int32_t code = tsdbReaderOpen(pVnode, &cond, &pTableKeyInfo[i], 1, pBlock, &pReader, pIdStr, false, NULL);
+    if (code != TSDB_CODE_SUCCESS) {
+      return code;
+    }
+
+    bool hasData = false;
+    code = tsdbNextDataBlock(pReader, &hasData);
+    if (!hasData || code != TSDB_CODE_SUCCESS) {
+      continue;
+    }
+
+    SColumnInfoData* pCol = taosArrayGet(pBlock->pDataBlock, 0);
+    int64_t k = *(int64_t*)pCol->pData;
+
+    if (key < k) {
+      key = k;
+    }
+
+    tsdbReaderClose(pReader);
+  }
+
+  return 0;
+}
diff --git a/source/dnode/vnode/src/vnd/vnodeSync.c b/source/dnode/vnode/src/vnd/vnodeSync.c
index 4ea5e3c6ec..29f1ddc50f 100644
--- a/source/dnode/vnode/src/vnd/vnodeSync.c
+++ b/source/dnode/vnode/src/vnd/vnodeSync.c
@@ -551,9 +551,9 @@ static void vnodeRestoreFinish(const SSyncFSM *pFsm, const SyncIndex commitIdx)
 
   // start to restore all stream tasks
   if (tsDisableStream) {
-    vInfo("vgId:%d, not restore stream tasks, since disabled", pVnode->config.vgId);
+    vInfo("vgId:%d, not launch stream tasks, since stream tasks are disabled", pVnode->config.vgId);
   } else {
-    vInfo("vgId:%d start to restore stream tasks", pVnode->config.vgId);
+    vInfo("vgId:%d start to launch stream tasks", pVnode->config.vgId);
     tqStartStreamTasks(pVnode->pTq);
   }
 }
diff --git a/source/libs/stream/inc/streamInc.h b/source/libs/stream/inc/streamInc.h
index c471bc2bd8..2c1956998a 100644
--- a/source/libs/stream/inc/streamInc.h
+++ b/source/libs/stream/inc/streamInc.h
@@ -33,8 +33,12 @@ typedef struct {
 
 static SStreamGlobalEnv streamEnv;
 
-int32_t streamDispatch(SStreamTask* pTask);
-int32_t streamDispatchReqToData(const SStreamDispatchReq* pReq, SStreamDataBlock* pData);
+int32_t streamDispatchStreamBlock(SStreamTask* pTask);
+
+SStreamDataBlock* createStreamDataFromDispatchMsg(const SStreamDispatchReq* pReq, int32_t blockType, int32_t srcVg);
+SStreamDataBlock* createStreamBlockFromResults(SStreamQueueItem* pItem, SStreamTask* pTask, int64_t resultSize, SArray* pRes);
+void    destroyStreamDataBlock(SStreamDataBlock* pBlock);
+
 int32_t streamRetrieveReqToData(const SStreamRetrieveReq* pReq, SStreamDataBlock* pData);
 int32_t streamDispatchAllBlocks(SStreamTask* pTask, const SStreamDataBlock* data);
 
diff --git a/source/libs/stream/src/stream.c b/source/libs/stream/src/stream.c
index 26e1c2ab43..8cc1ef1dd3 100644
--- a/source/libs/stream/src/stream.c
+++ b/source/libs/stream/src/stream.c
@@ -120,39 +120,35 @@ int32_t streamSchedExec(SStreamTask* pTask) {
 }
 
 int32_t streamTaskEnqueueBlocks(SStreamTask* pTask, const SStreamDispatchReq* pReq, SRpcMsg* pRsp) {
-  SStreamDataBlock* pData = taosAllocateQitem(sizeof(SStreamDataBlock), DEF_QITEM, 0);
-  int8_t            status;
+  int8_t status = 0;
 
-  // enqueue data block
-  if (pData != NULL) {
-    pData->type = STREAM_INPUT__DATA_BLOCK;
-    pData->srcVgId = pReq->dataSrcVgId;
-    // decode
-    /*pData->blocks = pReq->data;*/
-    /*pBlock->sourceVer = pReq->sourceVer;*/
-    streamDispatchReqToData(pReq, pData);
-    if (tAppendDataToInputQueue(pTask, (SStreamQueueItem*)pData) == 0) {
+  SStreamDataBlock* pBlock = createStreamDataFromDispatchMsg(pReq, STREAM_INPUT__DATA_BLOCK, pReq->dataSrcVgId);
+  if (pBlock == NULL) {
+    streamTaskInputFail(pTask);
+    status = TASK_INPUT_STATUS__FAILED;
+    qDebug("vgId:%d, s-task:%s failed to receive dispatch msg, reason: out of memory", pTask->pMeta->vgId,
+           pTask->id.idStr);
+  } else {
+    if (tAppendDataToInputQueue(pTask, (SStreamQueueItem*)pBlock) == 0) {
       status = TASK_INPUT_STATUS__NORMAL;
     } else {  // input queue is full, upstream is blocked now
       status = TASK_INPUT_STATUS__BLOCKED;
     }
-  } else {
-    streamTaskInputFail(pTask);
-    status = TASK_INPUT_STATUS__FAILED;
   }
 
   // rsp by input status
   void* buf = rpcMallocCont(sizeof(SMsgHead) + sizeof(SStreamDispatchRsp));
   ((SMsgHead*)buf)->vgId = htonl(pReq->upstreamNodeId);
-  SStreamDispatchRsp* pCont = POINTER_SHIFT(buf, sizeof(SMsgHead));
-  pCont->inputStatus = status;
-  pCont->streamId = htobe64(pReq->streamId);
-  pCont->upstreamNodeId = htonl(pReq->upstreamNodeId);
-  pCont->upstreamTaskId = htonl(pReq->upstreamTaskId);
-  pCont->downstreamNodeId = htonl(pTask->nodeId);
-  pCont->downstreamTaskId = htonl(pTask->id.taskId);
-  pRsp->pCont = buf;
+  SStreamDispatchRsp* pDispatchRsp = POINTER_SHIFT(buf, sizeof(SMsgHead));
 
+  pDispatchRsp->inputStatus = status;
+  pDispatchRsp->streamId = htobe64(pReq->streamId);
+  pDispatchRsp->upstreamNodeId = htonl(pReq->upstreamNodeId);
+  pDispatchRsp->upstreamTaskId = htonl(pReq->upstreamTaskId);
+  pDispatchRsp->downstreamNodeId = htonl(pTask->nodeId);
+  pDispatchRsp->downstreamTaskId = htonl(pTask->id.taskId);
+
+  pRsp->pCont = buf;
   pRsp->contLen = sizeof(SMsgHead) + sizeof(SStreamDispatchRsp);
   tmsgSendRsp(pRsp);
 
@@ -165,7 +161,7 @@ int32_t streamTaskEnqueueRetrieve(SStreamTask* pTask, SStreamRetrieveReq* pReq,
 
   // enqueue
   if (pData != NULL) {
-    qDebug("task %d(child %d) recv retrieve req from task %d, reqId %" PRId64, pTask->id.taskId, pTask->selfChildId,
+    qDebug("s-task:%s (child %d) recv retrieve req from task:0x%x, reqId %" PRId64, pTask->id.idStr, pTask->selfChildId,
            pReq->srcTaskId, pReq->reqId);
 
     pData->type = STREAM_INPUT__DATA_RETRIEVE;
@@ -197,30 +193,31 @@ int32_t streamTaskEnqueueRetrieve(SStreamTask* pTask, SStreamRetrieveReq* pReq,
   return status == TASK_INPUT_STATUS__NORMAL ? 0 : -1;
 }
 
-int32_t streamTaskOutput(SStreamTask* pTask, SStreamDataBlock* pBlock) {
+// todo add log
+int32_t streamTaskOutputResultBlock(SStreamTask* pTask, SStreamDataBlock* pBlock) {
   int32_t code = 0;
   if (pTask->outputType == TASK_OUTPUT__TABLE) {
     pTask->tbSink.tbSinkFunc(pTask, pTask->tbSink.vnode, 0, pBlock->blocks);
-    taosArrayDestroyEx(pBlock->blocks, (FDelete)blockDataFreeRes);
-    taosFreeQitem(pBlock);
+    destroyStreamDataBlock(pBlock);
   } else if (pTask->outputType == TASK_OUTPUT__SMA) {
     pTask->smaSink.smaSink(pTask->smaSink.vnode, pTask->smaSink.smaId, pBlock->blocks);
-    taosArrayDestroyEx(pBlock->blocks, (FDelete)blockDataFreeRes);
-    taosFreeQitem(pBlock);
+    destroyStreamDataBlock(pBlock);
   } else {
     ASSERT(pTask->outputType == TASK_OUTPUT__FIXED_DISPATCH || pTask->outputType == TASK_OUTPUT__SHUFFLE_DISPATCH);
     code = taosWriteQitem(pTask->outputQueue->queue, pBlock);
-    if (code != 0) {
+    if (code != 0) {  // todo failed to add it into the output queue, free it.
       return code;
     }
-    streamDispatch(pTask);
+
+    streamDispatchStreamBlock(pTask);
   }
+
   return 0;
 }
 
-int32_t streamProcessDispatchReq(SStreamTask* pTask, SStreamDispatchReq* pReq, SRpcMsg* pRsp, bool exec) {
-  qDebug("s-task:%s receive dispatch msg from taskId:%d(vgId:%d)", pTask->id.idStr, pReq->upstreamTaskId,
-         pReq->upstreamNodeId);
+int32_t streamProcessDispatchMsg(SStreamTask* pTask, SStreamDispatchReq* pReq, SRpcMsg* pRsp, bool exec) {
+  qDebug("s-task:%s receive dispatch msg from taskId:0x%x(vgId:%d), msgLen:%" PRId64, pTask->id.idStr,
+         pReq->upstreamTaskId, pReq->upstreamNodeId, pReq->totalLen);
 
   // todo add the input queue buffer limitation
   streamTaskEnqueueBlocks(pTask, pReq, pRsp);
@@ -257,8 +254,8 @@ int32_t streamProcessDispatchRsp(SStreamTask* pTask, SStreamDispatchRsp* pRsp, i
     return 0;
   }
 
-  // continue dispatch
-  streamDispatch(pTask);
+  // continue dispatch one block to down stream in pipeline
+  streamDispatchStreamBlock(pTask);
   return 0;
 }
 
@@ -268,13 +265,13 @@ int32_t streamProcessRunReq(SStreamTask* pTask) {
   }
 
   /*if (pTask->outputType == TASK_OUTPUT__FIXED_DISPATCH || pTask->outputType == TASK_OUTPUT__SHUFFLE_DISPATCH) {*/
-  /*streamDispatch(pTask);*/
+  /*streamDispatchStreamBlock(pTask);*/
   /*}*/
   return 0;
 }
 
 int32_t streamProcessRetrieveReq(SStreamTask* pTask, SStreamRetrieveReq* pReq, SRpcMsg* pRsp) {
-  qDebug("s-task:%s receive retrieve req from node %d taskId:%d", pTask->id.idStr, pReq->srcNodeId, pReq->srcTaskId);
+  qDebug("s-task:%s receive retrieve req from node %d taskId:0x%x", pTask->id.idStr, pReq->srcNodeId, pReq->srcTaskId);
   streamTaskEnqueueRetrieve(pTask, pReq, pRsp);
 
   ASSERT(pTask->taskLevel != TASK_LEVEL__SINK);
@@ -294,16 +291,13 @@ int32_t tAppendDataToInputQueue(SStreamTask* pTask, SStreamQueueItem* pItem) {
   double  size = QUEUE_MEM_SIZE_IN_MB(pTask->inputQueue->queue);
 
   if (type == STREAM_INPUT__DATA_SUBMIT) {
-    int32_t numOfBlocks = taosQueueItemSize(pTask->inputQueue->queue) + 1;
-    double  size = QUEUE_MEM_SIZE_IN_MB(pTask->inputQueue->queue);
-
     SStreamDataSubmit* px = (SStreamDataSubmit*)pItem;
     qDebug("s-task:%s submit enqueue msgLen:%d ver:%" PRId64 ", total in queue:%d, size:%.2fMiB", pTask->id.idStr,
-           px->submit.msgLen, px->submit.ver, numOfBlocks, size);
+           px->submit.msgLen, px->submit.ver, total, size);
 
     if ((pTask->taskLevel == TASK_LEVEL__SOURCE) && tInputQueueIsFull(pTask)) {
       qError("s-task:%s input queue is full, capacity(size:%d num:%dMiB), current(blocks:%d, size:%.2fMiB) abort",
-             pTask->id.idStr, STREAM_TASK_INPUT_QUEUEU_CAPACITY, STREAM_TASK_INPUT_QUEUEU_CAPACITY_IN_SIZE, numOfBlocks,
+             pTask->id.idStr, STREAM_TASK_INPUT_QUEUEU_CAPACITY, STREAM_TASK_INPUT_QUEUEU_CAPACITY_IN_SIZE, total,
              size);
       streamDataSubmitDestroy(px);
       taosFreeQitem(pItem);
@@ -312,22 +306,20 @@ int32_t tAppendDataToInputQueue(SStreamTask* pTask, SStreamQueueItem* pItem) {
     taosWriteQitem(pTask->inputQueue->queue, pItem);
   } else if (type == STREAM_INPUT__DATA_BLOCK || type == STREAM_INPUT__DATA_RETRIEVE ||
              type == STREAM_INPUT__REF_DATA_BLOCK) {
-    int32_t numOfBlocks = taosQueueItemSize(pTask->inputQueue->queue) + 1;
-    double  size = QUEUE_MEM_SIZE_IN_MB(pTask->inputQueue->queue);
-
     if ((pTask->taskLevel == TASK_LEVEL__SOURCE) && (tInputQueueIsFull(pTask))) {
       qError("s-task:%s input queue is full, capacity:%d size:%d MiB, current(blocks:%d, size:%.2fMiB) abort",
-             pTask->id.idStr, STREAM_TASK_INPUT_QUEUEU_CAPACITY, STREAM_TASK_INPUT_QUEUEU_CAPACITY_IN_SIZE, numOfBlocks,
+             pTask->id.idStr, STREAM_TASK_INPUT_QUEUEU_CAPACITY, STREAM_TASK_INPUT_QUEUEU_CAPACITY_IN_SIZE, total,
              size);
       return -1;
     }
 
-    qDebug("s-task:%s data block enqueue, total in queue:%d", pTask->id.idStr, numOfBlocks);
+    qDebug("s-task:%s data block enqueue, current(blocks:%d, size:%.2fMiB)", pTask->id.idStr, total, size);
     taosWriteQitem(pTask->inputQueue->queue, pItem);
   } else if (type == STREAM_INPUT__CHECKPOINT) {
     taosWriteQitem(pTask->inputQueue->queue, pItem);
   } else if (type == STREAM_INPUT__GET_RES) {
     taosWriteQitem(pTask->inputQueue->queue, pItem);
+    qDebug("s-task:%s data res enqueue, current(blocks:%d, size:%.2fMiB)", pTask->id.idStr, total, size);
   }
 
   if (type != STREAM_INPUT__GET_RES && type != STREAM_INPUT__CHECKPOINT && pTask->triggerParam != 0) {
diff --git a/source/libs/stream/src/streamData.c b/source/libs/stream/src/streamData.c
index b70a8c93a9..7c06e7deb3 100644
--- a/source/libs/stream/src/streamData.c
+++ b/source/libs/stream/src/streamData.c
@@ -15,20 +15,28 @@
 
 #include "streamInc.h"
 
-int32_t streamDispatchReqToData(const SStreamDispatchReq* pReq, SStreamDataBlock* pData) {
+SStreamDataBlock* createStreamDataFromDispatchMsg(const SStreamDispatchReq* pReq, int32_t blockType, int32_t srcVg) {
+  SStreamDataBlock* pData = taosAllocateQitem(sizeof(SStreamDataBlock), DEF_QITEM, pReq->totalLen);
+  if (pData == NULL) {
+    return NULL;
+  }
+
+  pData->type = blockType;
+  pData->srcVgId = srcVg;
+
   int32_t blockNum = pReq->blockNum;
   SArray* pArray = taosArrayInit_s(sizeof(SSDataBlock), blockNum);
   if (pArray == NULL) {
-    return -1;
+    return NULL;
   }
 
-  ASSERT(pReq->blockNum == taosArrayGetSize(pReq->data));
-  ASSERT(pReq->blockNum == taosArrayGetSize(pReq->dataLen));
+  ASSERT((pReq->blockNum == taosArrayGetSize(pReq->data)) && (pReq->blockNum == taosArrayGetSize(pReq->dataLen)));
 
   for (int32_t i = 0; i < blockNum; i++) {
     SRetrieveTableRsp* pRetrieve = (SRetrieveTableRsp*) taosArrayGetP(pReq->data, i);
     SSDataBlock*       pDataBlock = taosArrayGet(pArray, i);
     blockDecode(pDataBlock, pRetrieve->data);
+
     // TODO: refactor
     pDataBlock->info.window.skey = be64toh(pRetrieve->skey);
     pDataBlock->info.window.ekey = be64toh(pRetrieve->ekey);
@@ -39,8 +47,41 @@ int32_t streamDispatchReqToData(const SStreamDispatchReq* pReq, SStreamDataBlock
     pDataBlock->info.type = pRetrieve->streamBlockType;
     pDataBlock->info.childId = pReq->upstreamChildId;
   }
+
   pData->blocks = pArray;
-  return 0;
+  return pData;
+}
+
+SStreamDataBlock* createStreamBlockFromResults(SStreamQueueItem* pItem, SStreamTask* pTask, int64_t resultSize, SArray* pRes) {
+  SStreamDataBlock* pStreamBlocks = taosAllocateQitem(sizeof(SStreamDataBlock), DEF_QITEM, resultSize);
+  if (pStreamBlocks == NULL) {
+    taosArrayClearEx(pRes, (FDelete)blockDataFreeRes);
+    return NULL;
+  }
+
+  pStreamBlocks->type = STREAM_INPUT__DATA_BLOCK;
+  pStreamBlocks->blocks = pRes;
+
+  if (pItem->type == STREAM_INPUT__DATA_SUBMIT) {
+    SStreamDataSubmit* pSubmit = (SStreamDataSubmit*)pItem;
+    pStreamBlocks->childId = pTask->selfChildId;
+    pStreamBlocks->sourceVer = pSubmit->ver;
+  } else if (pItem->type == STREAM_INPUT__MERGED_SUBMIT) {
+    SStreamMergedSubmit* pMerged = (SStreamMergedSubmit*)pItem;
+    pStreamBlocks->childId = pTask->selfChildId;
+    pStreamBlocks->sourceVer = pMerged->ver;
+  }
+
+  return pStreamBlocks;
+}
+
+void destroyStreamDataBlock(SStreamDataBlock* pBlock) {
+  if (pBlock == NULL) {
+    return;
+  }
+
+  taosArrayDestroyEx(pBlock->blocks, (FDelete)blockDataFreeRes);
+  taosFreeQitem(pBlock);
 }
 
 int32_t streamRetrieveReqToData(const SStreamRetrieveReq* pReq, SStreamDataBlock* pData) {
@@ -184,11 +225,13 @@ void streamFreeQitem(SStreamQueueItem* data) {
     taosFreeQitem(data);
   } else if (type == STREAM_INPUT__MERGED_SUBMIT) {
     SStreamMergedSubmit* pMerge = (SStreamMergedSubmit*)data;
-    int32_t               sz = taosArrayGetSize(pMerge->submits);
+
+    int32_t sz = taosArrayGetSize(pMerge->submits);
     for (int32_t i = 0; i < sz; i++) {
       int32_t* pRef = taosArrayGetP(pMerge->dataRefs, i);
       int32_t  ref = atomic_sub_fetch_32(pRef, 1);
       ASSERT(ref >= 0);
+
       if (ref == 0) {
         SPackedData* pSubmit = (SPackedData*)taosArrayGet(pMerge->submits, i);
         taosMemoryFree(pSubmit->msgStr);
diff --git a/source/libs/stream/src/streamDispatch.c b/source/libs/stream/src/streamDispatch.c
index a757d39d3f..401a8b9e74 100644
--- a/source/libs/stream/src/streamDispatch.c
+++ b/source/libs/stream/src/streamDispatch.c
@@ -24,6 +24,7 @@ int32_t tEncodeStreamDispatchReq(SEncoder* pEncoder, const SStreamDispatchReq* p
   if (tEncodeI32(pEncoder, pReq->upstreamChildId) < 0) return -1;
   if (tEncodeI32(pEncoder, pReq->upstreamNodeId) < 0) return -1;
   if (tEncodeI32(pEncoder, pReq->blockNum) < 0) return -1;
+  if (tEncodeI64(pEncoder, pReq->totalLen) < 0) return -1;
   ASSERT(taosArrayGetSize(pReq->data) == pReq->blockNum);
   ASSERT(taosArrayGetSize(pReq->dataLen) == pReq->blockNum);
   for (int32_t i = 0; i < pReq->blockNum; i++) {
@@ -45,6 +46,8 @@ int32_t tDecodeStreamDispatchReq(SDecoder* pDecoder, SStreamDispatchReq* pReq) {
   if (tDecodeI32(pDecoder, &pReq->upstreamChildId) < 0) return -1;
   if (tDecodeI32(pDecoder, &pReq->upstreamNodeId) < 0) return -1;
   if (tDecodeI32(pDecoder, &pReq->blockNum) < 0) return -1;
+  if (tDecodeI64(pDecoder, &pReq->totalLen) < 0) return -1;
+
   ASSERT(pReq->blockNum > 0);
   pReq->data = taosArrayInit(pReq->blockNum, sizeof(void*));
   pReq->dataLen = taosArrayInit(pReq->blockNum, sizeof(int32_t));
@@ -135,7 +138,6 @@ int32_t streamBroadcastToChildren(SStreamTask* pTask, const SSDataBlock* pBlock)
     SStreamChildEpInfo* pEpInfo = taosArrayGetP(pTask->childEpInfo, i);
     req.dstNodeId = pEpInfo->nodeId;
     req.dstTaskId = pEpInfo->taskId;
-    int32_t code;
     int32_t len;
     tEncodeSize(tEncodeStreamRetrieveReq, &req, len, code);
     if (code < 0) {
@@ -155,30 +157,25 @@ int32_t streamBroadcastToChildren(SStreamTask* pTask, const SSDataBlock* pBlock)
     tEncodeStreamRetrieveReq(&encoder, &req);
     tEncoderClear(&encoder);
 
-    SRpcMsg rpcMsg = {
-        .code = 0,
-        .msgType = TDMT_STREAM_RETRIEVE,
-        .pCont = buf,
-        .contLen = sizeof(SMsgHead) + len,
-    };
-
+    SRpcMsg rpcMsg = { .code = 0, .msgType = TDMT_STREAM_RETRIEVE, .pCont = buf, .contLen = sizeof(SMsgHead) + len };
     if (tmsgSendReq(&pEpInfo->epSet, &rpcMsg) < 0) {
       ASSERT(0);
       goto CLEAR;
     }
-    buf = NULL;
 
-    qDebug("s-task:%s (child %d) send retrieve req to task %d at node %d, reqId %" PRId64, pTask->id.idStr,
+    buf = NULL;
+    qDebug("s-task:%s (child %d) send retrieve req to task %d at node %d, reqId:0x%" PRIx64, pTask->id.idStr,
            pTask->selfChildId, pEpInfo->taskId, pEpInfo->nodeId, req.reqId);
   }
   code = 0;
+
 CLEAR:
   taosMemoryFree(pRetrieve);
   rpcFreeCont(buf);
   return code;
 }
 
-static int32_t streamAddBlockToDispatchMsg(const SSDataBlock* pBlock, SStreamDispatchReq* pReq) {
+static int32_t streamAddBlockIntoDispatchMsg(const SSDataBlock* pBlock, SStreamDispatchReq* pReq) {
   int32_t dataStrLen = sizeof(SRetrieveTableRsp) + blockGetEncodeSize(pBlock);
   void*   buf = taosMemoryCalloc(1, dataStrLen);
   if (buf == NULL) return -1;
@@ -205,6 +202,7 @@ static int32_t streamAddBlockToDispatchMsg(const SSDataBlock* pBlock, SStreamDis
   taosArrayPush(pReq->dataLen, &actualLen);
   taosArrayPush(pReq->data, &buf);
 
+  pReq->totalLen += dataStrLen;
   return 0;
 }
 
@@ -291,7 +289,7 @@ int32_t streamDispatchOneRecoverFinishReq(SStreamTask* pTask, const SStreamRecov
   return 0;
 }
 
-int32_t streamDispatchOneDataReq(SStreamTask* pTask, const SStreamDispatchReq* pReq, int32_t vgId, SEpSet* pEpSet) {
+int32_t doSendDispatchMsg(SStreamTask* pTask, const SStreamDispatchReq* pReq, int32_t vgId, SEpSet* pEpSet) {
   void*   buf = NULL;
   int32_t code = -1;
   SRpcMsg msg = {0};
@@ -320,11 +318,12 @@ int32_t streamDispatchOneDataReq(SStreamTask* pTask, const SStreamDispatchReq* p
   msg.pCont = buf;
   msg.msgType = pTask->dispatchMsgType;
 
-  qDebug("dispatch from s-task:%s to taskId:%d vgId:%d data msg", pTask->id.idStr, pReq->taskId, vgId);
+  qDebug("dispatch from s-task:%s to taskId:0x%x vgId:%d data msg", pTask->id.idStr, pReq->taskId, vgId);
   tmsgSendReq(pEpSet, &msg);
 
   code = 0;
   return 0;
+
 FAIL:
   if (buf) rpcFreeCont(buf);
   return code;
@@ -360,7 +359,7 @@ int32_t streamSearchAndAddBlock(SStreamTask* pTask, SStreamDispatchReq* pReqs, S
     SVgroupInfo* pVgInfo = taosArrayGet(vgInfo, j);
     ASSERT(pVgInfo->vgId > 0);
     if (hashValue >= pVgInfo->hashBegin && hashValue <= pVgInfo->hashEnd) {
-      if (streamAddBlockToDispatchMsg(pDataBlock, &pReqs[j]) < 0) {
+      if (streamAddBlockIntoDispatchMsg(pDataBlock, &pReqs[j]) < 0) {
         return -1;
       }
       if (pReqs[j].blockNum == 0) {
@@ -376,9 +375,9 @@ int32_t streamSearchAndAddBlock(SStreamTask* pTask, SStreamDispatchReq* pReqs, S
 }
 
 int32_t streamDispatchAllBlocks(SStreamTask* pTask, const SStreamDataBlock* pData) {
-  int32_t code = -1;
-  int32_t blockNum = taosArrayGetSize(pData->blocks);
-  ASSERT(blockNum != 0);
+  int32_t code = 0;
+  int32_t numOfBlocks = taosArrayGetSize(pData->blocks);
+  ASSERT(numOfBlocks != 0);
 
   if (pTask->outputType == TASK_OUTPUT__FIXED_DISPATCH) {
     SStreamDispatchReq req = {
@@ -387,19 +386,25 @@ int32_t streamDispatchAllBlocks(SStreamTask* pTask, const SStreamDataBlock* pDat
         .upstreamTaskId = pTask->id.taskId,
         .upstreamChildId = pTask->selfChildId,
         .upstreamNodeId = pTask->nodeId,
-        .blockNum = blockNum,
+        .blockNum = numOfBlocks,
     };
 
-    req.data = taosArrayInit(blockNum, sizeof(void*));
-    req.dataLen = taosArrayInit(blockNum, sizeof(int32_t));
+    req.data = taosArrayInit(numOfBlocks, sizeof(void*));
+    req.dataLen = taosArrayInit(numOfBlocks, sizeof(int32_t));
     if (req.data == NULL || req.dataLen == NULL) {
-      goto FAIL_FIXED_DISPATCH;
+      taosArrayDestroyP(req.data, taosMemoryFree);
+      taosArrayDestroy(req.dataLen);
+      return TSDB_CODE_OUT_OF_MEMORY;
     }
 
-    for (int32_t i = 0; i < blockNum; i++) {
+    for (int32_t i = 0; i < numOfBlocks; i++) {
       SSDataBlock* pDataBlock = taosArrayGet(pData->blocks, i);
-      if (streamAddBlockToDispatchMsg(pDataBlock, &req) < 0) {
-        goto FAIL_FIXED_DISPATCH;
+      code = streamAddBlockIntoDispatchMsg(pDataBlock, &req);
+
+      if (code != TSDB_CODE_SUCCESS) {
+        taosArrayDestroyP(req.data, taosMemoryFree);
+        taosArrayDestroy(req.dataLen);
+        return code;
       }
     }
 
@@ -410,19 +415,12 @@ int32_t streamDispatchAllBlocks(SStreamTask* pTask, const SStreamDataBlock* pDat
     req.taskId = downstreamTaskId;
 
     qDebug("s-task:%s (child taskId:%d) fix-dispatch blocks:%d to down stream s-task:%d in vgId:%d", pTask->id.idStr,
-           pTask->selfChildId, blockNum, downstreamTaskId, vgId);
+           pTask->selfChildId, numOfBlocks, downstreamTaskId, vgId);
 
-    if (streamDispatchOneDataReq(pTask, &req, vgId, pEpSet) < 0) {
-      goto FAIL_FIXED_DISPATCH;
-    }
-
-    code = 0;
-
-  FAIL_FIXED_DISPATCH:
+    code = doSendDispatchMsg(pTask, &req, vgId, pEpSet);
     taosArrayDestroyP(req.data, taosMemoryFree);
     taosArrayDestroy(req.dataLen);
     return code;
-
   } else if (pTask->outputType == TASK_OUTPUT__SHUFFLE_DISPATCH) {
     int32_t rspCnt = atomic_load_32(&pTask->shuffleDispatcher.waitingRspCnt);
     ASSERT(rspCnt == 0);
@@ -452,13 +450,13 @@ int32_t streamDispatchAllBlocks(SStreamTask* pTask, const SStreamDataBlock* pDat
       pReqs[i].taskId = pVgInfo->taskId;
     }
 
-    for (int32_t i = 0; i < blockNum; i++) {
+    for (int32_t i = 0; i < numOfBlocks; i++) {
       SSDataBlock* pDataBlock = taosArrayGet(pData->blocks, i);
 
       // TODO: do not use broadcast
       if (pDataBlock->info.type == STREAM_DELETE_RESULT) {
         for (int32_t j = 0; j < vgSz; j++) {
-          if (streamAddBlockToDispatchMsg(pDataBlock, &pReqs[j]) < 0) {
+          if (streamAddBlockIntoDispatchMsg(pDataBlock, &pReqs[j]) < 0) {
             goto FAIL_SHUFFLE_DISPATCH;
           }
           if (pReqs[j].blockNum == 0) {
@@ -475,7 +473,7 @@ int32_t streamDispatchAllBlocks(SStreamTask* pTask, const SStreamDataBlock* pDat
     }
 
     qDebug("s-task:%s (child taskId:%d) shuffle-dispatch blocks:%d to %d vgroups", pTask->id.idStr, pTask->selfChildId,
-           blockNum, vgSz);
+           numOfBlocks, vgSz);
 
     for (int32_t i = 0; i < vgSz; i++) {
       if (pReqs[i].blockNum > 0) {
@@ -483,7 +481,7 @@ int32_t streamDispatchAllBlocks(SStreamTask* pTask, const SStreamDataBlock* pDat
         qDebug("s-task:%s (child taskId:%d) shuffle-dispatch blocks:%d to vgId:%d", pTask->id.idStr, pTask->selfChildId,
                pReqs[i].blockNum, pVgInfo->vgId);
 
-        if (streamDispatchOneDataReq(pTask, &pReqs[i], pVgInfo->vgId, &pVgInfo->epSet) < 0) {
+        if (doSendDispatchMsg(pTask, &pReqs[i], pVgInfo->vgId, &pVgInfo->epSet) < 0) {
           goto FAIL_SHUFFLE_DISPATCH;
         }
       }
@@ -501,9 +499,8 @@ int32_t streamDispatchAllBlocks(SStreamTask* pTask, const SStreamDataBlock* pDat
   return code;
 }
 
-int32_t streamDispatch(SStreamTask* pTask) {
+int32_t streamDispatchStreamBlock(SStreamTask* pTask) {
   ASSERT(pTask->outputType == TASK_OUTPUT__FIXED_DISPATCH || pTask->outputType == TASK_OUTPUT__SHUFFLE_DISPATCH);
-
   int32_t numOfElems = taosQueueItemSize(pTask->outputQueue->queue);
   if (numOfElems > 0) {
     qDebug("s-task:%s try to dispatch intermediate result block to downstream, elem in outputQ:%d", pTask->id.idStr,
@@ -517,23 +514,22 @@ int32_t streamDispatch(SStreamTask* pTask) {
     return 0;
   }
 
-  SStreamDataBlock* pBlock = streamQueueNextItem(pTask->outputQueue);
-  if (pBlock == NULL) {
+  SStreamDataBlock* pDispatchedBlock = streamQueueNextItem(pTask->outputQueue);
+  if (pDispatchedBlock == NULL) {
     qDebug("s-task:%s stop dispatching since no output in output queue", pTask->id.idStr);
     atomic_store_8(&pTask->outputStatus, TASK_OUTPUT_STATUS__NORMAL);
     return 0;
   }
 
-  ASSERT(pBlock->type == STREAM_INPUT__DATA_BLOCK);
+  ASSERT(pDispatchedBlock->type == STREAM_INPUT__DATA_BLOCK);
 
-  int32_t code = 0;
-  if (streamDispatchAllBlocks(pTask, pBlock) < 0) {
-    code = -1;
+  int32_t code = streamDispatchAllBlocks(pTask, pDispatchedBlock);
+  if (code != TSDB_CODE_SUCCESS) {
     streamQueueProcessFail(pTask->outputQueue);
     atomic_store_8(&pTask->outputStatus, TASK_OUTPUT_STATUS__NORMAL);
   }
 
-  taosArrayDestroyEx(pBlock->blocks, (FDelete)blockDataFreeRes);
-  taosFreeQitem(pBlock);
+  // this block can be freed only when it has been pushed to down stream.
+  destroyStreamDataBlock(pDispatchedBlock);
   return code;
 }
diff --git a/source/libs/stream/src/streamExec.c b/source/libs/stream/src/streamExec.c
index d14e8102d8..55474541ed 100644
--- a/source/libs/stream/src/streamExec.c
+++ b/source/libs/stream/src/streamExec.c
@@ -18,6 +18,9 @@
 // maximum allowed processed block batches. One block may include several submit blocks
 #define MAX_STREAM_EXEC_BATCH_NUM 128
 #define MIN_STREAM_EXEC_BATCH_NUM 16
+#define MAX_STREAM_RESULT_DUMP_THRESHOLD  1000
+
+static int32_t updateCheckPointInfo (SStreamTask* pTask);
 
 bool streamTaskShouldStop(const SStreamStatus* pStatus) {
   int32_t status = atomic_load_8((int8_t*)&pStatus->taskStatus);
@@ -29,56 +32,57 @@ bool streamTaskShouldPause(const SStreamStatus* pStatus) {
   return (status == TASK_STATUS__PAUSE);
 }
 
-static int32_t streamTaskExecImpl(SStreamTask* pTask, const void* data, SArray* pRes) {
+static int32_t doDumpResult(SStreamTask* pTask, SStreamQueueItem* pItem, SArray* pRes, int32_t size, int64_t* totalSize,
+                            int32_t* totalBlocks) {
+  int32_t code = updateCheckPointInfo(pTask);
+  if (code != TSDB_CODE_SUCCESS) {
+    taosArrayDestroyEx(pRes, (FDelete)blockDataFreeRes);
+    return code;
+  }
+
+  int32_t numOfBlocks = taosArrayGetSize(pRes);
+  if (numOfBlocks > 0) {
+    SStreamDataBlock* pStreamBlocks = createStreamBlockFromResults(pItem, pTask, size, pRes);
+    if (pStreamBlocks == NULL) {
+      taosArrayDestroyEx(pRes, (FDelete)blockDataFreeRes);
+      return -1;
+    }
+
+    qDebug("s-task:%s dump stream result data blocks, num:%d, size:%.2fMiB", pTask->id.idStr, numOfBlocks, size/1048576.0);
+
+    code = streamTaskOutputResultBlock(pTask, pStreamBlocks);
+    if (code == TSDB_CODE_UTIL_QUEUE_OUT_OF_MEMORY) { // back pressure and record position
+      destroyStreamDataBlock(pStreamBlocks);
+      return -1;
+    }
+
+    *totalSize += size;
+    *totalBlocks += numOfBlocks;
+  } else {
+    taosArrayDestroyEx(pRes, (FDelete)blockDataFreeRes);
+  }
+
+  return TSDB_CODE_SUCCESS;
+}
+
+static int32_t streamTaskExecImpl(SStreamTask* pTask, SStreamQueueItem* pItem, int64_t* totalSize, int32_t* totalBlocks) {
   int32_t code = TSDB_CODE_SUCCESS;
   void*   pExecutor = pTask->exec.pExecutor;
 
-  while (pTask->taskLevel == TASK_LEVEL__SOURCE) {
-    int8_t status = atomic_load_8(&pTask->status.taskStatus);
-    if (status != TASK_STATUS__NORMAL && status != TASK_STATUS__PAUSE) {
-      qError("stream task wait for the end of fill history, s-task:%s, status:%d", pTask->id.idStr,
-             atomic_load_8(&pTask->status.taskStatus));
-      taosMsleep(2);
-    } else {
-      break;
-    }
-  }
+  *totalBlocks = 0;
+  *totalSize = 0;
 
-  // set input
-  const SStreamQueueItem* pItem = (const SStreamQueueItem*)data;
-  if (pItem->type == STREAM_INPUT__GET_RES) {
-    const SStreamTrigger* pTrigger = (const SStreamTrigger*)data;
-    qSetMultiStreamInput(pExecutor, pTrigger->pBlock, 1, STREAM_INPUT__DATA_BLOCK);
-  } else if (pItem->type == STREAM_INPUT__DATA_SUBMIT) {
-    ASSERT(pTask->taskLevel == TASK_LEVEL__SOURCE);
-    const SStreamDataSubmit* pSubmit = (const SStreamDataSubmit*)data;
-    qSetMultiStreamInput(pExecutor, &pSubmit->submit, 1, STREAM_INPUT__DATA_SUBMIT);
-    qDebug("s-task:%s set submit blocks as source block completed, %p %p len:%d ver:%" PRId64, pTask->id.idStr, pSubmit,
-           pSubmit->submit.msgStr, pSubmit->submit.msgLen, pSubmit->submit.ver);
-  } else if (pItem->type == STREAM_INPUT__DATA_BLOCK || pItem->type == STREAM_INPUT__DATA_RETRIEVE) {
-    const SStreamDataBlock* pBlock = (const SStreamDataBlock*)data;
+  int32_t size = 0;
+  int32_t numOfBlocks = 0;
+  SArray* pRes = NULL;
 
-    SArray* pBlockList = pBlock->blocks;
-    int32_t numOfBlocks = taosArrayGetSize(pBlockList);
-    qDebug("s-task:%s set sdata blocks as input num:%d, ver:%" PRId64, pTask->id.idStr, numOfBlocks, pBlock->sourceVer);
-    qSetMultiStreamInput(pExecutor, pBlockList->pData, numOfBlocks, STREAM_INPUT__DATA_BLOCK);
-  } else if (pItem->type == STREAM_INPUT__MERGED_SUBMIT) {
-    const SStreamMergedSubmit* pMerged = (const SStreamMergedSubmit*)data;
-
-    SArray* pBlockList = pMerged->submits;
-    int32_t numOfBlocks = taosArrayGetSize(pBlockList);
-    qDebug("s-task:%s %p set submit input (merged), batch num:%d", pTask->id.idStr, pTask, numOfBlocks);
-    qSetMultiStreamInput(pExecutor, pBlockList->pData, numOfBlocks, STREAM_INPUT__MERGED_SUBMIT);
-  } else if (pItem->type == STREAM_INPUT__REF_DATA_BLOCK) {
-    const SStreamRefDataBlock* pRefBlock = (const SStreamRefDataBlock*)data;
-    qSetMultiStreamInput(pExecutor, pRefBlock->pBlock, 1, STREAM_INPUT__DATA_BLOCK);
-  } else {
-    ASSERT(0);
-  }
-
-  // pExecutor
   while (1) {
+    if (pRes == NULL) {
+      pRes = taosArrayInit(4, sizeof(SSDataBlock));
+    }
+
     if (streamTaskShouldStop(&pTask->status)) {
+      taosArrayDestroy(pRes); // memory leak
       return 0;
     }
 
@@ -97,17 +101,18 @@ static int32_t streamTaskExecImpl(SStreamTask* pTask, const void* data, SArray*
       if (pItem->type == STREAM_INPUT__DATA_RETRIEVE) {
         SSDataBlock block = {0};
 
-        const SStreamDataBlock* pRetrieveBlock = (const SStreamDataBlock*)data;
+        const SStreamDataBlock* pRetrieveBlock = (const SStreamDataBlock*) pItem;
         ASSERT(taosArrayGetSize(pRetrieveBlock->blocks) == 1);
 
         assignOneDataBlock(&block, taosArrayGet(pRetrieveBlock->blocks, 0));
         block.info.type = STREAM_PULL_OVER;
         block.info.childId = pTask->selfChildId;
         taosArrayPush(pRes, &block);
-
-        qDebug("task %d(child %d) processed retrieve, reqId %" PRId64, pTask->id.taskId, pTask->selfChildId,
+        numOfBlocks += 1;
+        qDebug("s-task:%s(child %d) processed retrieve, reqId:0x%" PRIx64, pTask->id.idStr, pTask->selfChildId,
                pRetrieveBlock->reqId);
       }
+
       break;
     }
 
@@ -118,15 +123,40 @@ static int32_t streamTaskExecImpl(SStreamTask* pTask, const void* data, SArray*
       continue;
     }
 
-    qDebug("s-task:%s (child %d) executed and get block", pTask->id.idStr, pTask->selfChildId);
-
     SSDataBlock block = {0};
     assignOneDataBlock(&block, output);
     block.info.childId = pTask->selfChildId;
+
+    size += blockDataGetSize(output) + sizeof(SSDataBlock) + sizeof(SColumnInfoData) * blockDataGetNumOfCols(&block);
+    numOfBlocks += 1;
+
     taosArrayPush(pRes, &block);
+
+    qDebug("s-task:%s (child %d) executed and get block, total blocks:%d, size:%.2fMiB", pTask->id.idStr,
+           pTask->selfChildId, numOfBlocks, size / 1048576.0);
+
+    // current output should be dispatched to down stream nodes
+    if (numOfBlocks >= MAX_STREAM_RESULT_DUMP_THRESHOLD) {
+      ASSERT(numOfBlocks == taosArrayGetSize(pRes));
+      code = doDumpResult(pTask, pItem, pRes, size, totalSize, totalBlocks);
+      if (code != TSDB_CODE_SUCCESS) {
+        return code;
+      }
+
+      pRes = NULL;
+      size = 0;
+      numOfBlocks = 0;
+    }
   }
 
-  return 0;
+  if (numOfBlocks > 0) {
+    ASSERT(numOfBlocks == taosArrayGetSize(pRes));
+    code = doDumpResult(pTask, pItem, pRes, size, totalSize, totalBlocks);
+  } else {
+    taosArrayDestroy(pRes);
+  }
+
+  return code;
 }
 
 int32_t streamScanExec(SStreamTask* pTask, int32_t batchSz) {
@@ -200,7 +230,7 @@ int32_t streamScanExec(SStreamTask* pTask, int32_t batchSz) {
 
     qRes->type = STREAM_INPUT__DATA_BLOCK;
     qRes->blocks = pRes;
-    code = streamTaskOutput(pTask, qRes);
+    code = streamTaskOutputResultBlock(pTask, qRes);
     if (code == TSDB_CODE_UTIL_QUEUE_OUT_OF_MEMORY) {
       taosArrayDestroyEx(pRes, (FDelete)blockDataFreeRes);
       taosFreeQitem(qRes);
@@ -209,7 +239,7 @@ int32_t streamScanExec(SStreamTask* pTask, int32_t batchSz) {
 
     if (pTask->outputType == TASK_OUTPUT__FIXED_DISPATCH || pTask->outputType == TASK_OUTPUT__SHUFFLE_DISPATCH) {
       qDebug("s-task:%s scan exec dispatch blocks:%d", pTask->id.idStr, batchCnt);
-      streamDispatch(pTask);
+      streamDispatchStreamBlock(pTask);
     }
 
     if (finished) {
@@ -246,7 +276,7 @@ int32_t streamBatchExec(SStreamTask* pTask, int32_t batchLimit) {
 
   if (pTask->taskLevel == TASK_LEVEL__SINK) {
     ASSERT(((SStreamQueueItem*)pItem)->type == STREAM_INPUT__DATA_BLOCK);
-    streamTaskOutput(pTask, (SStreamDataBlock*)pItem);
+    streamTaskOutputResultBlock(pTask, (SStreamDataBlock*)pItem);
   }
 
   // exec impl
@@ -257,6 +287,34 @@ int32_t streamBatchExec(SStreamTask* pTask, int32_t batchLimit) {
 }
 #endif
 
+int32_t updateCheckPointInfo (SStreamTask* pTask) {
+  int64_t ckId = 0;
+  int64_t dataVer = 0;
+  qGetCheckpointVersion(pTask->exec.pExecutor, &dataVer, &ckId);
+
+  SCheckpointInfo* pCkInfo = &pTask->chkInfo;
+  if (ckId > pCkInfo->id) {  // save it since the checkpoint is updated
+    qDebug("s-task:%s exec end, start to update check point, ver from %" PRId64 " to %" PRId64
+           ", checkPoint id:%" PRId64 " -> %" PRId64, pTask->id.idStr, pCkInfo->version, dataVer, pCkInfo->id, ckId);
+
+    pTask->chkInfo = (SCheckpointInfo){.version = dataVer, .id = ckId, .currentVer = pCkInfo->currentVer};
+
+    taosWLockLatch(&pTask->pMeta->lock);
+
+    streamMetaSaveTask(pTask->pMeta, pTask);
+    if (streamMetaCommit(pTask->pMeta) < 0) {
+      taosWUnLockLatch(&pTask->pMeta->lock);
+      qError("s-task:%s failed to commit stream meta, since %s", pTask->id.idStr, terrstr());
+      return -1;
+    } else {
+      taosWUnLockLatch(&pTask->pMeta->lock);
+      qDebug("s-task:%s update checkpoint ver succeed", pTask->id.idStr);
+    }
+  }
+
+  return TSDB_CODE_SUCCESS;
+}
+
 int32_t streamExecForAll(SStreamTask* pTask) {
   int32_t code = 0;
   while (1) {
@@ -272,6 +330,7 @@ int32_t streamExecForAll(SStreamTask* pTask) {
       if (streamTaskShouldPause(&pTask->status)) {
         return 0;
       }
+
       SStreamQueueItem* qItem = streamQueueNextItem(pTask->inputQueue);
       if (qItem == NULL) {
         if (pTask->taskLevel == TASK_LEVEL__SOURCE && batchSize < MIN_STREAM_EXEC_BATCH_NUM && times < 5) {
@@ -324,74 +383,70 @@ int32_t streamExecForAll(SStreamTask* pTask) {
     if (pTask->taskLevel == TASK_LEVEL__SINK) {
       ASSERT(pInput->type == STREAM_INPUT__DATA_BLOCK);
       qDebug("s-task:%s sink node start to sink result. numOfBlocks:%d", pTask->id.idStr, batchSize);
-      streamTaskOutput(pTask, (SStreamDataBlock*)pInput);
+      streamTaskOutputResultBlock(pTask, (SStreamDataBlock*)pInput);
       continue;
     }
 
-    SArray* pRes = taosArrayInit(0, sizeof(SSDataBlock));
+    // wait for the task to be ready to go
+    while (pTask->taskLevel == TASK_LEVEL__SOURCE) {
+      int8_t status = atomic_load_8(&pTask->status.taskStatus);
+      if (status != TASK_STATUS__NORMAL && status != TASK_STATUS__PAUSE) {
+        qError("stream task wait for the end of fill history, s-task:%s, status:%d", pTask->id.idStr,
+               atomic_load_8(&pTask->status.taskStatus));
+        taosMsleep(2);
+      } else {
+        break;
+      }
+    }
+
+    int64_t st = taosGetTimestampMs();
     qDebug("s-task:%s start to execute, block batches:%d", pTask->id.idStr, batchSize);
 
-    streamTaskExecImpl(pTask, pInput, pRes);
+    {
+      // set input
+      void*   pExecutor = pTask->exec.pExecutor;
 
-    int64_t ckId = 0;
-    int64_t dataVer = 0;
-    qGetCheckpointVersion(pTask->exec.pExecutor, &dataVer, &ckId);
-    if (ckId > pTask->chkInfo.id) {  // save it since the checkpoint is updated
-      qDebug("s-task:%s exec end, start to update check point, ver from %" PRId64 " to %" PRId64
-             ", checkPoint id:%" PRId64 " -> %" PRId64,
-             pTask->id.idStr, pTask->chkInfo.version, dataVer, pTask->chkInfo.id, ckId);
+      const SStreamQueueItem* pItem = pInput;
+      if (pItem->type == STREAM_INPUT__GET_RES) {
+        const SStreamTrigger* pTrigger = (const SStreamTrigger*)pInput;
+        qSetMultiStreamInput(pExecutor, pTrigger->pBlock, 1, STREAM_INPUT__DATA_BLOCK);
+      } else if (pItem->type == STREAM_INPUT__DATA_SUBMIT) {
+        ASSERT(pTask->taskLevel == TASK_LEVEL__SOURCE);
+        const SStreamDataSubmit* pSubmit = (const SStreamDataSubmit*)pInput;
+        qSetMultiStreamInput(pExecutor, &pSubmit->submit, 1, STREAM_INPUT__DATA_SUBMIT);
+        qDebug("s-task:%s set submit blocks as source block completed, %p %p len:%d ver:%" PRId64, pTask->id.idStr, pSubmit,
+               pSubmit->submit.msgStr, pSubmit->submit.msgLen, pSubmit->submit.ver);
+      } else if (pItem->type == STREAM_INPUT__DATA_BLOCK || pItem->type == STREAM_INPUT__DATA_RETRIEVE) {
+        const SStreamDataBlock* pBlock = (const SStreamDataBlock*)pInput;
 
-      pTask->chkInfo = (SCheckpointInfo){.version = dataVer, .id = ckId, .currentVer = pTask->chkInfo.currentVer};
+        SArray* pBlockList = pBlock->blocks;
+        int32_t numOfBlocks = taosArrayGetSize(pBlockList);
+        qDebug("s-task:%s set sdata blocks as input num:%d, ver:%" PRId64, pTask->id.idStr, numOfBlocks, pBlock->sourceVer);
+        qSetMultiStreamInput(pExecutor, pBlockList->pData, numOfBlocks, STREAM_INPUT__DATA_BLOCK);
+      } else if (pItem->type == STREAM_INPUT__MERGED_SUBMIT) {
+        const SStreamMergedSubmit* pMerged = (const SStreamMergedSubmit*)pInput;
 
-      taosWLockLatch(&pTask->pMeta->lock);
-
-      streamMetaSaveTask(pTask->pMeta, pTask);
-      if (streamMetaCommit(pTask->pMeta) < 0) {
-        taosWUnLockLatch(&pTask->pMeta->lock);
-        qError("s-task:%s failed to commit stream meta, since %s", pTask->id.idStr, terrstr());
-        return -1;
+        SArray* pBlockList = pMerged->submits;
+        int32_t numOfBlocks = taosArrayGetSize(pBlockList);
+        qDebug("s-task:%s %p set submit input (merged), batch num:%d", pTask->id.idStr, pTask, numOfBlocks);
+        qSetMultiStreamInput(pExecutor, pBlockList->pData, numOfBlocks, STREAM_INPUT__MERGED_SUBMIT);
+      } else if (pItem->type == STREAM_INPUT__REF_DATA_BLOCK) {
+        const SStreamRefDataBlock* pRefBlock = (const SStreamRefDataBlock*)pInput;
+        qSetMultiStreamInput(pExecutor, pRefBlock->pBlock, 1, STREAM_INPUT__DATA_BLOCK);
       } else {
-        taosWUnLockLatch(&pTask->pMeta->lock);
-        qDebug("s-task:%s update checkpoint ver succeed", pTask->id.idStr);
+        ASSERT(0);
       }
-    } else {
-      qDebug("s-task:%s exec end", pTask->id.idStr);
     }
 
-    if (taosArrayGetSize(pRes) != 0) {
-      SStreamDataBlock* qRes = taosAllocateQitem(sizeof(SStreamDataBlock), DEF_QITEM, 0);
-      if (qRes == NULL) {
-        taosArrayDestroyEx(pRes, (FDelete)blockDataFreeRes);
-        streamFreeQitem(pInput);
-        return -1;
-      }
+    int64_t resSize = 0;
+    int32_t totalBlocks = 0;
+    streamTaskExecImpl(pTask, pInput, &resSize, &totalBlocks);
 
-      qRes->type = STREAM_INPUT__DATA_BLOCK;
-      qRes->blocks = pRes;
-
-      if (((SStreamQueueItem*)pInput)->type == STREAM_INPUT__DATA_SUBMIT) {
-        SStreamDataSubmit* pSubmit = (SStreamDataSubmit*)pInput;
-        qRes->childId = pTask->selfChildId;
-        qRes->sourceVer = pSubmit->ver;
-      } else if (((SStreamQueueItem*)pInput)->type == STREAM_INPUT__MERGED_SUBMIT) {
-        SStreamMergedSubmit* pMerged = (SStreamMergedSubmit*)pInput;
-        qRes->childId = pTask->selfChildId;
-        qRes->sourceVer = pMerged->ver;
-      }
-
-      code = streamTaskOutput(pTask, qRes);
-      if (code == TSDB_CODE_UTIL_QUEUE_OUT_OF_MEMORY) {
-        // backpressure and record position
-        taosArrayDestroyEx(pRes, (FDelete)blockDataFreeRes);
-        streamFreeQitem(pInput);
-        taosFreeQitem(qRes);
-        return -1;
-      }
-    } else {
-      taosArrayDestroy(pRes);
-    }
+    double  el = (taosGetTimestampMs() - st) / 1000.0;
+    qDebug("s-task:%s exec end, elapsed time:%.2fs, result size:%.2fMiB, numOfBlocks:%d", pTask->id.idStr, el, resSize / 1048576.0, totalBlocks);
     streamFreeQitem(pInput);
   }
+
   return 0;
 }
 
diff --git a/source/libs/stream/src/streamMeta.c b/source/libs/stream/src/streamMeta.c
index 682ce08c7f..33375fe921 100644
--- a/source/libs/stream/src/streamMeta.c
+++ b/source/libs/stream/src/streamMeta.c
@@ -296,6 +296,7 @@ int32_t streamMetaBegin(SStreamMeta* pMeta) {
   return 0;
 }
 
+// todo add error log
 int32_t streamMetaCommit(SStreamMeta* pMeta) {
   if (tdbCommit(pMeta->db, pMeta->txn) < 0) {
     qError("failed to commit stream meta");
@@ -311,6 +312,7 @@ int32_t streamMetaCommit(SStreamMeta* pMeta) {
                TDB_TXN_WRITE | TDB_TXN_READ_UNCOMMITTED) < 0) {
     return -1;
   }
+
   return 0;
 }
 
@@ -373,7 +375,7 @@ int32_t streamLoadTasks(SStreamMeta* pMeta, int64_t ver) {
     }
 
     if (pTask->fillHistory) {
-      pTask->status.taskStatus = TASK_STATUS__WAIT_DOWNSTREAM;
+      ASSERT(pTask->status.taskStatus == TASK_STATUS__WAIT_DOWNSTREAM);
       streamTaskCheckDownstream(pTask, ver);
     }
   }
diff --git a/source/libs/stream/src/streamRecover.c b/source/libs/stream/src/streamRecover.c
index f71d078a3d..eb2535782e 100644
--- a/source/libs/stream/src/streamRecover.c
+++ b/source/libs/stream/src/streamRecover.c
@@ -20,7 +20,7 @@ int32_t streamTaskLaunchRecover(SStreamTask* pTask, int64_t version) {
 
   if (pTask->taskLevel == TASK_LEVEL__SOURCE) {
     atomic_store_8(&pTask->status.taskStatus, TASK_STATUS__RECOVER_PREPARE);
-    qDebug("s-task:%s set task status:%d and start recover", pTask->id.idStr, pTask->status.taskStatus);
+    qDebug("s-task:%s set task status:%d and start to recover", pTask->id.idStr, pTask->status.taskStatus);
 
     streamSetParamForRecover(pTask);
     streamSourceRecoverPrepareStep1(pTask, version);
@@ -46,6 +46,7 @@ int32_t streamTaskLaunchRecover(SStreamTask* pTask, int64_t version) {
     streamSetParamForRecover(pTask);
     streamAggRecoverPrepare(pTask);
   } else if (pTask->taskLevel == TASK_LEVEL__SINK) {
+    // sink nodes has no specified operation for fill history
     atomic_store_8(&pTask->status.taskStatus, TASK_STATUS__NORMAL);
   }
 
@@ -54,7 +55,7 @@ int32_t streamTaskLaunchRecover(SStreamTask* pTask, int64_t version) {
 
 // checkstatus
 int32_t streamTaskCheckDownstream(SStreamTask* pTask, int64_t version) {
-  qDebug("s-taks:%s in fill history stage, ver:%"PRId64, pTask->id.idStr, version);
+  qDebug("s-task:%s in fill history stage, ver:%"PRId64, pTask->id.idStr, version);
 
   SStreamTaskCheckReq req = {
       .streamId = pTask->id.streamId,
@@ -71,23 +72,23 @@ int32_t streamTaskCheckDownstream(SStreamTask* pTask, int64_t version) {
     req.downstreamTaskId = pTask->fixedEpDispatcher.taskId;
     pTask->checkReqId = req.reqId;
 
-    qDebug("s-task:%s at node %d check downstream task %d at node %d", pTask->id.idStr, pTask->nodeId, req.downstreamTaskId,
+    qDebug("s-task:%s at node %d check downstream task:0x%x at node %d", pTask->id.idStr, pTask->nodeId, req.downstreamTaskId,
            req.downstreamNodeId);
     streamDispatchCheckMsg(pTask, &req, pTask->fixedEpDispatcher.nodeId, &pTask->fixedEpDispatcher.epSet);
   } else if (pTask->outputType == TASK_OUTPUT__SHUFFLE_DISPATCH) {
     SArray* vgInfo = pTask->shuffleDispatcher.dbInfo.pVgroupInfos;
 
-    int32_t vgSz = taosArrayGetSize(vgInfo);
-    pTask->recoverTryingDownstream = vgSz;
-    pTask->checkReqIds = taosArrayInit(vgSz, sizeof(int64_t));
+    int32_t numOfVgs = taosArrayGetSize(vgInfo);
+    pTask->recoverTryingDownstream = numOfVgs;
+    pTask->checkReqIds = taosArrayInit(numOfVgs, sizeof(int64_t));
 
-    for (int32_t i = 0; i < vgSz; i++) {
+    for (int32_t i = 0; i < numOfVgs; i++) {
       SVgroupInfo* pVgInfo = taosArrayGet(vgInfo, i);
       req.reqId = tGenIdPI64();
       taosArrayPush(pTask->checkReqIds, &req.reqId);
       req.downstreamNodeId = pVgInfo->vgId;
       req.downstreamTaskId = pVgInfo->taskId;
-      qDebug("s-task:%s at node %d check downstream task %d at node %d (shuffle)", pTask->id.idStr, pTask->nodeId,
+      qDebug("s-task:%s at node %d check downstream task:0x%x at node %d (shuffle)", pTask->id.idStr, pTask->nodeId,
              req.downstreamTaskId, req.downstreamNodeId);
       streamDispatchCheckMsg(pTask, &req, pVgInfo->vgId, &pVgInfo->epSet);
     }
@@ -110,15 +111,16 @@ int32_t streamRecheckOneDownstream(SStreamTask* pTask, const SStreamTaskCheckRsp
       .childId = pRsp->childId,
   };
 
-  qDebug("s-task:%s at node %d check downstream task %d at node %d (recheck)", pTask->id.idStr, pTask->nodeId,
+  qDebug("s-task:%s at node %d check downstream task:0x%x at node %d (recheck)", pTask->id.idStr, pTask->nodeId,
          req.downstreamTaskId, req.downstreamNodeId);
 
   if (pTask->outputType == TASK_OUTPUT__FIXED_DISPATCH) {
     streamDispatchCheckMsg(pTask, &req, pRsp->downstreamNodeId, &pTask->fixedEpDispatcher.epSet);
   } else if (pTask->outputType == TASK_OUTPUT__SHUFFLE_DISPATCH) {
     SArray* vgInfo = pTask->shuffleDispatcher.dbInfo.pVgroupInfos;
-    int32_t vgSz = taosArrayGetSize(vgInfo);
-    for (int32_t i = 0; i < vgSz; i++) {
+
+    int32_t numOfVgs = taosArrayGetSize(vgInfo);
+    for (int32_t i = 0; i < numOfVgs; i++) {
       SVgroupInfo* pVgInfo = taosArrayGet(vgInfo, i);
       if (pVgInfo->taskId == req.downstreamTaskId) {
         streamDispatchCheckMsg(pTask, &req, pRsp->downstreamNodeId, &pVgInfo->epSet);
@@ -134,7 +136,9 @@ int32_t streamTaskCheckStatus(SStreamTask* pTask) {
 }
 
 int32_t streamProcessTaskCheckRsp(SStreamTask* pTask, const SStreamTaskCheckRsp* pRsp, int64_t version) {
-  qDebug("task %d at node %d recv check rsp from task %d at node %d: status %d", pRsp->upstreamTaskId,
+  ASSERT(pTask->id.taskId == pRsp->upstreamTaskId);
+
+  qDebug("s-task:%s at node %d recv check rsp from task:0x%x at node %d: status %d", pTask->id.idStr,
          pRsp->upstreamNodeId, pRsp->downstreamTaskId, pRsp->downstreamNodeId, pRsp->status);
 
   if (pRsp->status == 1) {
@@ -161,7 +165,7 @@ int32_t streamProcessTaskCheckRsp(SStreamTask* pTask, const SStreamTaskCheckRsp*
         taosArrayDestroy(pTask->checkReqIds);
         pTask->checkReqIds = NULL;
 
-        qDebug("s-task:%s all downstream tasks:%d are ready, now enter into recover stage", pTask->id.idStr, numOfReqs);
+        qDebug("s-task:%s all %d downstream tasks are ready, now enter into recover stage", pTask->id.idStr, numOfReqs);
         streamTaskLaunchRecover(pTask, version);
       }
     } else if (pTask->outputType == TASK_OUTPUT__FIXED_DISPATCH) {
@@ -174,9 +178,10 @@ int32_t streamProcessTaskCheckRsp(SStreamTask* pTask, const SStreamTaskCheckRsp*
       ASSERT(0);
     }
   } else { // not ready, wait for 100ms and retry
-    qDebug("s-task:%s downstream taskId:%d (vgId:%d) not ready, wait for 100ms and retry", pTask->id.idStr,
+    qDebug("s-task:%s downstream taskId:0x%x (vgId:%d) not ready, wait for 100ms and retry", pTask->id.idStr,
         pRsp->downstreamTaskId, pRsp->downstreamNodeId);
     taosMsleep(100);
+
     streamRecheckOneDownstream(pTask, pRsp);
   }