diff --git a/source/libs/stream/inc/streamsm.h b/source/libs/stream/inc/streamsm.h
index 4b87dcfe84..c2a351a297 100644
--- a/source/libs/stream/inc/streamsm.h
+++ b/source/libs/stream/inc/streamsm.h
@@ -55,6 +55,7 @@ struct SStreamTaskSM {
   SArray*          pTransList;  // SArray<STaskStateTrans>
   int64_t          stateTs;
   SStreamTask*     pTask;
+  STaskStateTrans* pActiveTrans;
 };
 
 typedef struct SStreamEventInfo {
diff --git a/source/libs/stream/src/streamTaskSm.c b/source/libs/stream/src/streamTaskSm.c
index b6bd53eb87..c219556c6f 100644
--- a/source/libs/stream/src/streamTaskSm.c
+++ b/source/libs/stream/src/streamTaskSm.c
@@ -38,6 +38,7 @@ static int32_t         initStateTransferTable(SStreamTaskSM* pSM);
 static int32_t dummyFn(SStreamTask* UNUSED_PARAM(p)) { return 0; }
 static int32_t streamTaskStartCheckDownstream(SStreamTask* pTask) {
   stDebug("s-task:%s start to check downstream tasks", pTask->id.idStr);
+  streamTaskCheckDownstream(pTask);
   return 0;
 }
 static int32_t streamTaskDoPause(SStreamTask* pTask) {
@@ -84,21 +85,33 @@ SStreamTaskSM* streamCreateStateMachine(SStreamTask* pTask) {
     taosMemoryFree(pSM);
     return NULL;
   }
-
   return pSM;
 }
 
 int32_t taskSMHandleEvent(SStreamTaskSM* pSM, const EStreamTaskEvent* pEvent) {
   STaskStateTrans* pTrans = streamTaskFindTransform(pSM, pEvent);
-  qDebug("start to handle event:%d", *pEvent);
+  ASSERT(pSM->pActiveTrans == NULL);
 
-  pSM->current = pTrans->next;
+  stDebug("start to handle event:%d, state:%s", *pEvent, pSM->current.name);
+  pSM->pActiveTrans = pTrans;
   pSM->stateTs = taosGetTimestampMs();
-  qDebug("new state:%s from %s", pTrans->next.name, pSM->current.name);
-
   return pTrans->pAction(pSM->pTask);
 }
 
+int32_t taskSMOnHandleEventSuccess(SStreamTaskSM* pSM) {
+  STaskStateTrans*  pTrans = pSM->pActiveTrans;
+  EStreamTaskEvent* pEvent = &pTrans->event;
+
+  int64_t el = (taosGetTimestampMs() - pSM->stateTs);
+  stDebug("handle event:%d completed, elapsd time:%" PRId64 "ms new state:%s from %s", *pEvent, el, pTrans->next.name,
+          pSM->current.name);
+
+  // todo: add lock
+  pSM->current = pTrans->next;
+}
+
+
+
 STaskStateTrans createStateTransform(ETaskStatus current, ETaskStatus next, EStreamTaskEvent event, __state_trans_fn fn) {
   STaskStateTrans trans = {0};
   trans.state = StreamTaskStatusList[current];