diff --git a/include/libs/stream/tstream.h b/include/libs/stream/tstream.h
index 8e7dd0bb0d..1d4bbf073e 100644
--- a/include/libs/stream/tstream.h
+++ b/include/libs/stream/tstream.h
@@ -78,11 +78,11 @@ enum {
   TASK_TRIGGER_STATUS__ACTIVE,
 };
 
-enum {
+typedef enum {
   TASK_LEVEL__SOURCE = 1,
   TASK_LEVEL__AGG,
   TASK_LEVEL__SINK,
-};
+} ETASK_LEVEL;
 
 enum {
   TASK_OUTPUT__FIXED_DISPATCH = 1,
@@ -284,13 +284,13 @@ struct SStreamTask {
   int16_t         dispatchMsgType;
   SStreamStatus   status;
   int32_t         selfChildId;
-  int32_t         nodeId;
+  int32_t         nodeId;      // vgroup id
   SEpSet          epSet;
   SCheckpointInfo chkInfo;
   STaskExec       exec;
-
-  // fill history
-  int8_t fillHistory;
+  int8_t          fillHistory;  // fill history
+  int64_t         ekey;         // end ts key
+  int64_t         endVer;       // end version
 
   // children info
   SArray* childEpInfo;  // SArray<SStreamChildEpInfo*>
@@ -351,7 +351,7 @@ typedef struct SStreamMeta {
 int32_t tEncodeStreamEpInfo(SEncoder* pEncoder, const SStreamChildEpInfo* pInfo);
 int32_t tDecodeStreamEpInfo(SDecoder* pDecoder, SStreamChildEpInfo* pInfo);
 
-SStreamTask* tNewStreamTask(int64_t streamId);
+SStreamTask* tNewStreamTask(int64_t streamId, int8_t taskLevel, int8_t fillHistory, int64_t triggerParam, SArray* pTaskList);
 int32_t      tEncodeStreamTask(SEncoder* pEncoder, const SStreamTask* pTask);
 int32_t      tDecodeStreamTask(SDecoder* pDecoder, SStreamTask* pTask);
 void         tFreeStreamTask(SStreamTask* pTask);
diff --git a/source/dnode/mnode/impl/inc/mndDef.h b/source/dnode/mnode/impl/inc/mndDef.h
index 7d707f4cba..82b714e6eb 100644
--- a/source/dnode/mnode/impl/inc/mndDef.h
+++ b/source/dnode/mnode/impl/inc/mndDef.h
@@ -663,9 +663,10 @@ typedef struct {
   char    targetDb[TSDB_DB_FNAME_LEN];
   char    targetSTbName[TSDB_TABLE_FNAME_LEN];
   int64_t targetStbUid;
-  int32_t fixedSinkVgId;  // 0 for shuffle
+
   // fixedSinkVg is not applicable for encode and decode
   SVgObj fixedSinkVg;
+  int32_t fixedSinkVgId;  // 0 for shuffle
 
   // transformation
   char*          sql;
diff --git a/source/dnode/mnode/impl/src/mndScheduler.c b/source/dnode/mnode/impl/src/mndScheduler.c
index 734f624be0..df8c11a6f6 100644
--- a/source/dnode/mnode/impl/src/mndScheduler.c
+++ b/source/dnode/mnode/impl/src/mndScheduler.c
@@ -14,18 +14,8 @@
  */
 
 #include "mndScheduler.h"
-#include "mndConsumer.h"
 #include "mndDb.h"
-#include "mndDnode.h"
-#include "mndMnode.h"
-#include "mndShow.h"
 #include "mndSnode.h"
-#include "mndStb.h"
-#include "mndStream.h"
-#include "mndSubscribe.h"
-#include "mndTopic.h"
-#include "mndTrans.h"
-#include "mndUser.h"
 #include "mndVgroup.h"
 #include "parser.h"
 #include "tcompare.h"
@@ -34,12 +24,8 @@
 
 extern bool tsDeployOnSnode;
 
-static int32_t mndAddTaskToTaskSet(SArray* pArray, SStreamTask* pTask) {
-  int32_t childId = taosArrayGetSize(pArray);
-  pTask->selfChildId = childId;
-  taosArrayPush(pArray, &pTask);
-  return 0;
-}
+static int32_t mndAddSinkTaskToStream(SStreamObj* pStream, SMnode* pMnode, int32_t vgId, SVgObj* pVgroup);
+static void setFixedDownstreamEpInfo(SStreamTask* pDstTask, const SStreamTask* pTask);
 
 int32_t mndConvertRsmaTask(char** pDst, int32_t* pDstLen, const char* ast, int64_t uid, int8_t triggerType,
                            int64_t watermark, int64_t deleteMark) {
@@ -97,7 +83,7 @@ END:
   return terrno;
 }
 
-int32_t mndAddSinkToTask(SMnode* pMnode, SStreamObj* pStream, SStreamTask* pTask) {
+int32_t mndSetSinkTaskInfo(SStreamObj* pStream, SStreamTask* pTask) {
   if (pStream->smaId != 0) {
     pTask->outputType = TASK_OUTPUT__SMA;
     pTask->smaSink.smaId = pStream->smaId;
@@ -106,16 +92,23 @@ int32_t mndAddSinkToTask(SMnode* pMnode, SStreamObj* pStream, SStreamTask* pTask
     pTask->tbSink.stbUid = pStream->targetStbUid;
     memcpy(pTask->tbSink.stbFullName, pStream->targetSTbName, TSDB_TABLE_FNAME_LEN);
     pTask->tbSink.pSchemaWrapper = tCloneSSchemaWrapper(&pStream->outputSchema);
+    if (pTask->tbSink.pSchemaWrapper == NULL) {
+      return TSDB_CODE_OUT_OF_MEMORY;
+    }
   }
+
   return 0;
 }
 
-int32_t mndAddDispatcherToInnerTask(SMnode* pMnode, SStreamObj* pStream, SStreamTask* pTask) {
+#define SINK_NODE_LEVEL (0)
+
+int32_t mndAddDispatcherForInnerTask(SMnode* pMnode, SStreamObj* pStream, SStreamTask* pTask) {
   bool isShuffle = false;
 
   if (pStream->fixedSinkVgId == 0) {
     SDbObj* pDb = mndAcquireDb(pMnode, pStream->targetDb);
     if (pDb != NULL && pDb->cfg.numOfVgroups > 1) {
+
       isShuffle = true;
       pTask->outputType = TASK_OUTPUT__SHUFFLE_DISPATCH;
       pTask->dispatchMsgType = TDMT_STREAM_TASK_DISPATCH;
@@ -127,47 +120,46 @@ int32_t mndAddDispatcherToInnerTask(SMnode* pMnode, SStreamObj* pStream, SStream
     sdbRelease(pMnode->pSdb, pDb);
   }
 
+  SArray* pSinkNodeList = taosArrayGetP(pStream->tasks, SINK_NODE_LEVEL);
+  int32_t numOfSinkNodes = taosArrayGetSize(pSinkNodeList);
+
   if (isShuffle) {
     memcpy(pTask->shuffleDispatcher.stbFullName, pStream->targetSTbName, TSDB_TABLE_FNAME_LEN);
     SArray* pVgs = pTask->shuffleDispatcher.dbInfo.pVgroupInfos;
-    int32_t sz = taosArrayGetSize(pVgs);
-    SArray* sinkLv = taosArrayGetP(pStream->tasks, 0);
-    int32_t sinkLvSize = taosArrayGetSize(sinkLv);
-    for (int32_t i = 0; i < sz; i++) {
+
+    int32_t numOfVgroups = taosArrayGetSize(pVgs);
+    for (int32_t i = 0; i < numOfVgroups; i++) {
       SVgroupInfo* pVgInfo = taosArrayGet(pVgs, i);
-      for (int32_t j = 0; j < sinkLvSize; j++) {
-        SStreamTask* pLastLevelTask = taosArrayGetP(sinkLv, j);
-        if (pLastLevelTask->nodeId == pVgInfo->vgId) {
-          pVgInfo->taskId = pLastLevelTask->id.taskId;
+
+      for (int32_t j = 0; j < numOfSinkNodes; j++) {
+        SStreamTask* pSinkTask = taosArrayGetP(pSinkNodeList, j);
+        if (pSinkTask->nodeId == pVgInfo->vgId) {
+          pVgInfo->taskId = pSinkTask->id.taskId;
           break;
         }
       }
     }
   } else {
-    pTask->outputType = TASK_OUTPUT__FIXED_DISPATCH;
-    pTask->dispatchMsgType = TDMT_STREAM_TASK_DISPATCH;
-    SArray* pArray = taosArrayGetP(pStream->tasks, 0);
-    // one sink only
-    SStreamTask* lastLevelTask = taosArrayGetP(pArray, 0);
-    pTask->fixedEpDispatcher.taskId = lastLevelTask->id.taskId;
-    pTask->fixedEpDispatcher.nodeId = lastLevelTask->nodeId;
-    pTask->fixedEpDispatcher.epSet = lastLevelTask->epSet;
+    SStreamTask* pOneSinkTask = taosArrayGetP(pSinkNodeList, 0);
+    setFixedDownstreamEpInfo(pTask, pOneSinkTask);
   }
+
   return 0;
 }
 
-int32_t mndAssignTaskToVg(SMnode* pMnode, SStreamTask* pTask, SSubplan* plan, const SVgObj* pVgroup) {
+int32_t mndAssignStreamTaskToVgroup(SMnode* pMnode, SStreamTask* pTask, SSubplan* plan, const SVgObj* pVgroup) {
   int32_t msgLen;
+
   pTask->nodeId = pVgroup->vgId;
   pTask->epSet = mndGetVgroupEpset(pMnode, pVgroup);
 
-  plan->execNode.nodeId = pVgroup->vgId;
+  plan->execNode.nodeId = pTask->nodeId;
   plan->execNode.epSet = pTask->epSet;
-
   if (qSubPlanToString(plan, &pTask->exec.qmsg, &msgLen) < 0) {
     terrno = TSDB_CODE_QRY_INVALID_INPUT;
     return -1;
   }
+
   return 0;
 }
 
@@ -210,100 +202,121 @@ SVgObj* mndSchedFetchOneVg(SMnode* pMnode, int64_t dbUid) {
   return pVgroup;
 }
 
+// create sink node for each vgroup.
 int32_t mndAddShuffleSinkTasksToStream(SMnode* pMnode, SStreamObj* pStream) {
   SSdb*   pSdb = pMnode->pSdb;
   void*   pIter = NULL;
-  SArray* tasks = taosArrayGetP(pStream->tasks, 0);
 
   while (1) {
     SVgObj* pVgroup = NULL;
     pIter = sdbFetch(pSdb, SDB_VGROUP, pIter, (void**)&pVgroup);
-    if (pIter == NULL) break;
+    if (pIter == NULL) {
+      break;
+    }
+
     if (!mndVgroupInDb(pVgroup, pStream->targetDbUid)) {
       sdbRelease(pSdb, pVgroup);
       continue;
     }
 
-    SStreamTask* pTask = tNewStreamTask(pStream->uid);
-    if (pTask == NULL) {
-      sdbRelease(pSdb, pVgroup);
-      terrno = TSDB_CODE_OUT_OF_MEMORY;
-      return -1;
-    }
-    pTask->fillHistory = pStream->fillHistory;
-    mndAddTaskToTaskSet(tasks, pTask);
-
-    pTask->nodeId = pVgroup->vgId;
-    pTask->epSet = mndGetVgroupEpset(pMnode, pVgroup);
-
-    // type
-    pTask->taskLevel = TASK_LEVEL__SINK;
-
-    // sink
-    if (pStream->smaId != 0) {
-      pTask->outputType = TASK_OUTPUT__SMA;
-      pTask->smaSink.smaId = pStream->smaId;
-    } else {
-      pTask->outputType = TASK_OUTPUT__TABLE;
-      pTask->tbSink.stbUid = pStream->targetStbUid;
-      memcpy(pTask->tbSink.stbFullName, pStream->targetSTbName, TSDB_TABLE_FNAME_LEN);
-      pTask->tbSink.pSchemaWrapper = tCloneSSchemaWrapper(&pStream->outputSchema);
-      if (pTask->tbSink.pSchemaWrapper == NULL) {
-        terrno = TSDB_CODE_OUT_OF_MEMORY;
-        return -1;
-      }
-    }
+    mndAddSinkTaskToStream(pStream, pMnode, pVgroup->vgId, pVgroup);
     sdbRelease(pSdb, pVgroup);
   }
+
   return 0;
 }
 
-int32_t mndAddFixedSinkTaskToStream(SMnode* pMnode, SStreamObj* pStream) {
-  SArray*      tasks = taosArrayGetP(pStream->tasks, 0);
-  SStreamTask* pTask = tNewStreamTask(pStream->uid);
+int32_t mndAddSinkTaskToStream(SStreamObj* pStream, SMnode* pMnode, int32_t vgId, SVgObj* pVgroup) {
+  SArray* pTaskList = taosArrayGetP(pStream->tasks, SINK_NODE_LEVEL);
+
+  SStreamTask* pTask = tNewStreamTask(pStream->uid, TASK_LEVEL__SINK, pStream->fillHistory, 0, pTaskList);
   if (pTask == NULL) {
     terrno = TSDB_CODE_OUT_OF_MEMORY;
     return -1;
   }
-  pTask->fillHistory = pStream->fillHistory;
-  mndAddTaskToTaskSet(tasks, pTask);
 
-  pTask->nodeId = pStream->fixedSinkVgId;
-#if 0
-  SVgObj* pVgroup = mndAcquireVgroup(pMnode, pStream->fixedSinkVgId);
-  if (pVgroup == NULL) {
-    return -1;
-  }
+  pTask->nodeId = vgId;
   pTask->epSet = mndGetVgroupEpset(pMnode, pVgroup);
-#endif
-  pTask->epSet = mndGetVgroupEpset(pMnode, &pStream->fixedSinkVg);
-
-  pTask->taskLevel = TASK_LEVEL__SINK;
-
-  // sink
-  if (pStream->smaId != 0) {
-    pTask->outputType = TASK_OUTPUT__SMA;
-    pTask->smaSink.smaId = pStream->smaId;
-  } else {
-    pTask->outputType = TASK_OUTPUT__TABLE;
-    pTask->tbSink.stbUid = pStream->targetStbUid;
-    memcpy(pTask->tbSink.stbFullName, pStream->targetSTbName, TSDB_TABLE_FNAME_LEN);
-    pTask->tbSink.pSchemaWrapper = tCloneSSchemaWrapper(&pStream->outputSchema);
-  }
-
+  mndSetSinkTaskInfo(pStream, pTask);
   return 0;
 }
 
+static int32_t mndScheduleFillHistoryStreamTask(SMnode* pMnode, SStreamObj* pStream) {
+  return 0;
+}
+
+static int32_t addSourceStreamTask(SMnode* pMnode, SVgObj* pVgroup, SArray* pTaskList, SStreamObj* pStream,
+                                   SSubplan* plan, uint64_t uid, int8_t taskLevel, int8_t fillHistory,
+                                   bool hasExtraSink) {
+  SStreamTask* pTask = tNewStreamTask(uid, taskLevel, fillHistory, pStream->triggerParam, pTaskList);
+  if (pTask == NULL) {
+    return terrno;
+  }
+
+  // sink or dispatch
+  if (hasExtraSink) {
+    mndAddDispatcherForInnerTask(pMnode, pStream, pTask);
+  } else {
+    mndSetSinkTaskInfo(pStream, pTask);
+  }
+
+  if (mndAssignStreamTaskToVgroup(pMnode, pTask, plan, pVgroup) < 0) {
+    return terrno;
+  }
+
+  return TSDB_CODE_SUCCESS;
+}
+
+static SStreamChildEpInfo* createStreamTaskEpInfo(SStreamTask* pTask) {
+  SStreamChildEpInfo* pEpInfo = taosMemoryMalloc(sizeof(SStreamChildEpInfo));
+  if (pEpInfo == NULL) {
+    terrno = TSDB_CODE_OUT_OF_MEMORY;
+    return NULL;
+  }
+
+  pEpInfo->childId = pTask->selfChildId;
+  pEpInfo->epSet = pTask->epSet;
+  pEpInfo->nodeId = pTask->nodeId;
+  pEpInfo->taskId = pTask->id.taskId;
+
+  return pEpInfo;
+}
+
+void setFixedDownstreamEpInfo(SStreamTask* pDstTask, const SStreamTask* pTask) {
+  STaskDispatcherFixedEp* pDispatcher = &pDstTask->fixedEpDispatcher;
+  pDispatcher->taskId = pTask->id.taskId;
+  pDispatcher->nodeId = pTask->nodeId;
+  pDispatcher->epSet = pTask->epSet;
+
+  pDstTask->outputType = TASK_OUTPUT__FIXED_DISPATCH;
+  pDstTask->dispatchMsgType = TDMT_STREAM_TASK_DISPATCH;
+}
+
+int32_t appendToUpstream(SStreamTask* pTask, SStreamTask* pUpstream) {
+  SStreamChildEpInfo* pEpInfo = createStreamTaskEpInfo(pTask);
+  if (pEpInfo == NULL) {
+    return TSDB_CODE_OUT_OF_MEMORY;
+  }
+
+  if(pUpstream->childEpInfo == NULL) {
+    pUpstream->childEpInfo = taosArrayInit(4, POINTER_BYTES);
+  }
+  
+  taosArrayPush(pUpstream->childEpInfo, &pEpInfo);
+  return TSDB_CODE_SUCCESS;
+}
+
 int32_t mndScheduleStream(SMnode* pMnode, SStreamObj* pStream) {
-  SSdb*       pSdb = pMnode->pSdb;
+  SSdb* pSdb = pMnode->pSdb;
+
   SQueryPlan* pPlan = qStringToQueryPlan(pStream->physicalPlan);
   if (pPlan == NULL) {
     terrno = TSDB_CODE_QRY_INVALID_INPUT;
     return -1;
   }
-  int32_t planTotLevel = LIST_LENGTH(pPlan->pSubplans);
 
-  pStream->tasks = taosArrayInit(planTotLevel, sizeof(void*));
+  int32_t planTotLevel = LIST_LENGTH(pPlan->pSubplans);
+  pStream->tasks = taosArrayInit(planTotLevel, POINTER_BYTES);
 
   bool    hasExtraSink = false;
   bool    externalTargetDB = strcmp(pStream->sourceDb, pStream->targetDb) != 0;
@@ -313,13 +326,13 @@ int32_t mndScheduleStream(SMnode* pMnode, SStreamObj* pStream) {
     return -1;
   }
 
-  bool multiTarget = pDbObj->cfg.numOfVgroups > 1;
+  bool multiTarget = (pDbObj->cfg.numOfVgroups > 1);
   sdbRelease(pSdb, pDbObj);
 
   if (planTotLevel == 2 || externalTargetDB || multiTarget || pStream->fixedSinkVgId) {
-    /*if (true) {*/
-    SArray* taskOneLevel = taosArrayInit(0, sizeof(void*));
+    SArray* taskOneLevel = taosArrayInit(0, POINTER_BYTES);
     taosArrayPush(pStream->tasks, &taskOneLevel);
+
     // add extra sink
     hasExtraSink = true;
     if (pStream->fixedSinkVgId == 0) {
@@ -328,19 +341,20 @@ int32_t mndScheduleStream(SMnode* pMnode, SStreamObj* pStream) {
         return -1;
       }
     } else {
-      if (mndAddFixedSinkTaskToStream(pMnode, pStream) < 0) {
+      if (mndAddSinkTaskToStream(pStream, pMnode, pStream->fixedSinkVgId, &pStream->fixedSinkVg) < 0) {
         // TODO free
         return -1;
       }
     }
   }
+
   pStream->totalLevel = planTotLevel + hasExtraSink;
 
   if (planTotLevel > 1) {
     SStreamTask* pInnerTask;
     // inner level
     {
-      SArray* taskInnerLevel = taosArrayInit(0, sizeof(void*));
+      SArray* taskInnerLevel = taosArrayInit(0, POINTER_BYTES);
       taosArrayPush(pStream->tasks, &taskInnerLevel);
 
       SNodeListNode* inner = (SNodeListNode*)nodesListGetNode(pPlan->pSubplans, 0);
@@ -350,25 +364,15 @@ int32_t mndScheduleStream(SMnode* pMnode, SStreamObj* pStream) {
         return -1;
       }
 
-      pInnerTask = tNewStreamTask(pStream->uid);
+      pInnerTask = tNewStreamTask(pStream->uid, TASK_LEVEL__AGG, pStream->fillHistory, pStream->triggerParam, taskInnerLevel);
       if (pInnerTask == NULL) {
         terrno = TSDB_CODE_OUT_OF_MEMORY;
         qDestroyQueryPlan(pPlan);
         return -1;
       }
 
-      pInnerTask->fillHistory = pStream->fillHistory;
-      mndAddTaskToTaskSet(taskInnerLevel, pInnerTask);
-
-      pInnerTask->childEpInfo = taosArrayInit(0, sizeof(void*));
-
-      pInnerTask->taskLevel = TASK_LEVEL__AGG;
-
-      // trigger
-      pInnerTask->triggerParam = pStream->triggerParam;
-
       // dispatch
-      if (mndAddDispatcherToInnerTask(pMnode, pStream, pInnerTask) < 0) {
+      if (mndAddDispatcherForInnerTask(pMnode, pStream, pInnerTask) < 0) {
         qDestroyQueryPlan(pPlan);
         return -1;
       }
@@ -377,7 +381,7 @@ int32_t mndScheduleStream(SMnode* pMnode, SStreamObj* pStream) {
         SSnodeObj* pSnode = mndSchedFetchOneSnode(pMnode);
         if (pSnode == NULL) {
           SVgObj* pVgroup = mndSchedFetchOneVg(pMnode, pStream->sourceDbUid);
-          if (mndAssignTaskToVg(pMnode, pInnerTask, plan, pVgroup) < 0) {
+          if (mndAssignStreamTaskToVgroup(pMnode, pInnerTask, plan, pVgroup) < 0) {
             sdbRelease(pSdb, pVgroup);
             qDestroyQueryPlan(pPlan);
             return -1;
@@ -392,17 +396,18 @@ int32_t mndScheduleStream(SMnode* pMnode, SStreamObj* pStream) {
         }
       } else {
         SVgObj* pVgroup = mndSchedFetchOneVg(pMnode, pStream->sourceDbUid);
-        if (mndAssignTaskToVg(pMnode, pInnerTask, plan, pVgroup) < 0) {
+        if (mndAssignStreamTaskToVgroup(pMnode, pInnerTask, plan, pVgroup) < 0) {
           sdbRelease(pSdb, pVgroup);
           qDestroyQueryPlan(pPlan);
           return -1;
         }
+
         sdbRelease(pSdb, pVgroup);
       }
     }
 
     // source level
-    SArray* taskSourceLevel = taosArrayInit(0, sizeof(void*));
+    SArray* taskSourceLevel = taosArrayInit(0, POINTER_BYTES);
     taosArrayPush(pStream->tasks, &taskSourceLevel);
 
     SNodeListNode* inner = (SNodeListNode*)nodesListGetNode(pPlan->pSubplans, 1);
@@ -416,66 +421,52 @@ int32_t mndScheduleStream(SMnode* pMnode, SStreamObj* pStream) {
     while (1) {
       SVgObj* pVgroup;
       pIter = sdbFetch(pSdb, SDB_VGROUP, pIter, (void**)&pVgroup);
-      if (pIter == NULL) break;
+      if (pIter == NULL) {
+        break;
+      }
+
       if (!mndVgroupInDb(pVgroup, pStream->sourceDbUid)) {
         sdbRelease(pSdb, pVgroup);
         continue;
       }
 
-      SStreamTask* pTask = tNewStreamTask(pStream->uid);
+      SStreamTask* pTask = tNewStreamTask(pStream->uid, TASK_LEVEL__SOURCE, pStream->fillHistory, 0, taskSourceLevel);
       if (pTask == NULL) {
         terrno = TSDB_CODE_OUT_OF_MEMORY;
         sdbRelease(pSdb, pVgroup);
         qDestroyQueryPlan(pPlan);
         return -1;
       }
-      pTask->fillHistory = pStream->fillHistory;
-      mndAddTaskToTaskSet(taskSourceLevel, pTask);
 
-      pTask->triggerParam = 0;
+      // all the source tasks dispatch result to a single agg node.
+      setFixedDownstreamEpInfo(pTask, pInnerTask);
 
-      // source
-      pTask->taskLevel = TASK_LEVEL__SOURCE;
-
-      // add fixed vg dispatch
-      pTask->dispatchMsgType = TDMT_STREAM_TASK_DISPATCH;
-      pTask->outputType = TASK_OUTPUT__FIXED_DISPATCH;
-
-      pTask->fixedEpDispatcher.taskId = pInnerTask->id.taskId;
-      pTask->fixedEpDispatcher.nodeId = pInnerTask->nodeId;
-      pTask->fixedEpDispatcher.epSet = pInnerTask->epSet;
-
-      if (mndAssignTaskToVg(pMnode, pTask, plan, pVgroup) < 0) {
+      if (mndAssignStreamTaskToVgroup(pMnode, pTask, plan, pVgroup) < 0) {
         sdbRelease(pSdb, pVgroup);
         qDestroyQueryPlan(pPlan);
         return -1;
       }
 
-      SStreamChildEpInfo* pEpInfo = taosMemoryMalloc(sizeof(SStreamChildEpInfo));
-      if (pEpInfo == NULL) {
-        terrno = TSDB_CODE_OUT_OF_MEMORY;
-        sdbRelease(pSdb, pVgroup);
-        qDestroyQueryPlan(pPlan);
-        return -1;
-      }
-      pEpInfo->childId = pTask->selfChildId;
-      pEpInfo->epSet = pTask->epSet;
-      pEpInfo->nodeId = pTask->nodeId;
-      pEpInfo->taskId = pTask->id.taskId;
-      taosArrayPush(pInnerTask->childEpInfo, &pEpInfo);
+      int32_t code = appendToUpstream(pTask, pInnerTask);
       sdbRelease(pSdb, pVgroup);
-    }
-  }
 
-  if (planTotLevel == 1) {
-    SArray* taskOneLevel = taosArrayInit(0, sizeof(void*));
-    taosArrayPush(pStream->tasks, &taskOneLevel);
+      if (code != TSDB_CODE_SUCCESS) {
+        terrno = code;
+        qDestroyQueryPlan(pPlan);
+        return -1;
+      }
+    }
+  } else if (planTotLevel == 1) {
+    // create exec stream task, since only one level, the exec task is also the source task
+    SArray* pTaskList = taosArrayInit(0, POINTER_BYTES);
+    taosArrayPush(pStream->tasks, &pTaskList);
 
     SNodeListNode* inner = (SNodeListNode*)nodesListGetNode(pPlan->pSubplans, 0);
     if (LIST_LENGTH(inner->pNodeList) != 1) {
       terrno = TSDB_CODE_QRY_INVALID_INPUT;
       return -1;
     }
+
     SSubplan* plan = (SSubplan*)nodesListGetNode(inner->pNodeList, 0);
     if (plan->subplanType != SUBPLAN_TYPE_SCAN) {
       terrno = TSDB_CODE_QRY_INVALID_INPUT;
@@ -486,42 +477,26 @@ int32_t mndScheduleStream(SMnode* pMnode, SStreamObj* pStream) {
     while (1) {
       SVgObj* pVgroup;
       pIter = sdbFetch(pSdb, SDB_VGROUP, pIter, (void**)&pVgroup);
-      if (pIter == NULL) break;
+      if (pIter == NULL) {
+        break;
+      }
+
       if (!mndVgroupInDb(pVgroup, pStream->sourceDbUid)) {
         sdbRelease(pSdb, pVgroup);
         continue;
       }
 
-      SStreamTask* pTask = tNewStreamTask(pStream->uid);
-      if (pTask == NULL) {
-        sdbRelease(pSdb, pVgroup);
-        qDestroyQueryPlan(pPlan);
-        return -1;
-      }
-      pTask->fillHistory = pStream->fillHistory;
-      mndAddTaskToTaskSet(taskOneLevel, pTask);
-
-      // source
-      pTask->taskLevel = TASK_LEVEL__SOURCE;
-
-      // trigger
-      pTask->triggerParam = pStream->triggerParam;
-
-      // sink or dispatch
-      if (hasExtraSink) {
-        mndAddDispatcherToInnerTask(pMnode, pStream, pTask);
-      } else {
-        mndAddSinkToTask(pMnode, pStream, pTask);
-      }
-
-      if (mndAssignTaskToVg(pMnode, pTask, plan, pVgroup) < 0) {
-        sdbRelease(pSdb, pVgroup);
-        qDestroyQueryPlan(pPlan);
-        return -1;
-      }
+      // new stream task
+      int32_t code = addSourceStreamTask(pMnode, pVgroup, pTaskList, pStream, plan, pStream->uid, TASK_LEVEL__SOURCE, pStream->fillHistory, hasExtraSink);
       sdbRelease(pSdb, pVgroup);
+
+      if (code != TSDB_CODE_SUCCESS) {
+        qDestroyQueryPlan(pPlan);
+        return -1;
+      }
     }
   }
+
   qDestroyQueryPlan(pPlan);
   return 0;
 }
diff --git a/source/dnode/mnode/impl/src/mndStream.c b/source/dnode/mnode/impl/src/mndStream.c
index 0713150b48..39a1fa223f 100644
--- a/source/dnode/mnode/impl/src/mndStream.c
+++ b/source/dnode/mnode/impl/src/mndStream.c
@@ -700,6 +700,7 @@ static int32_t mndProcessCreateStreamReq(SRpcMsg *pReq) {
       if (pStream->sourceDbUid == streamObj.sourceDbUid) {
         ++numOfStream;
       }
+
       sdbRelease(pMnode->pSdb, pStream);
       if (numOfStream > MND_STREAM_MAX_NUM) {
         mError("too many streams, no more than %d for each database", MND_STREAM_MAX_NUM);
@@ -723,6 +724,7 @@ static int32_t mndProcessCreateStreamReq(SRpcMsg *pReq) {
     pDb = NULL;
     goto _OVER;
   }
+
   mndReleaseDb(pMnode, pDb);
 
   STrans *pTrans = mndTransCreate(pMnode, TRN_POLICY_ROLLBACK, TRN_CONFLICT_DB_INSIDE, pReq, "create-stream");
diff --git a/source/libs/stream/src/streamTask.c b/source/libs/stream/src/streamTask.c
index 8a03896978..a0caffd41f 100644
--- a/source/libs/stream/src/streamTask.c
+++ b/source/libs/stream/src/streamTask.c
@@ -17,14 +17,25 @@
 #include "tstream.h"
 #include "wal.h"
 
-SStreamTask* tNewStreamTask(int64_t streamId) {
+static int32_t mndAddToTaskset(SArray* pArray, SStreamTask* pTask) {
+  int32_t childId = taosArrayGetSize(pArray);
+  pTask->selfChildId = childId;
+  taosArrayPush(pArray, &pTask);
+  return 0;
+}
+
+SStreamTask* tNewStreamTask(int64_t streamId, int8_t taskLevel, int8_t fillHistory, int64_t triggerParam, SArray* pTaskList) {
   SStreamTask* pTask = (SStreamTask*)taosMemoryCalloc(1, sizeof(SStreamTask));
   if (pTask == NULL) {
+    terrno = TSDB_CODE_OUT_OF_MEMORY;
     return NULL;
   }
 
   pTask->id.taskId = tGenIdPI32();
   pTask->id.streamId = streamId;
+  pTask->taskLevel = taskLevel;
+  pTask->fillHistory = fillHistory;
+  pTask->triggerParam = triggerParam;
 
   char buf[128] = {0};
   sprintf(buf, "0x%" PRIx64 "-%d", pTask->id.streamId, pTask->id.taskId);
@@ -34,6 +45,7 @@ SStreamTask* tNewStreamTask(int64_t streamId) {
   pTask->inputStatus = TASK_INPUT_STATUS__NORMAL;
   pTask->outputStatus = TASK_OUTPUT_STATUS__NORMAL;
 
+  mndAddToTaskset(pTaskList, pTask);
   return pTask;
 }