diff --git a/include/libs/scheduler/scheduler.h b/include/libs/scheduler/scheduler.h
index 70ac7a630460a2917f11b93984e4c1434567e6ef..e6973cd390c10ff524f70549d161090582ee56ab 100644
--- a/include/libs/scheduler/scheduler.h
+++ b/include/libs/scheduler/scheduler.h
@@ -25,11 +25,6 @@ extern "C" {
 
 extern tsem_t schdRspSem;
 
-typedef struct SSchedulerCfg {
-  uint32_t maxJobNum;
-  int32_t  maxNodeTableNum;
-} SSchedulerCfg;
-
 typedef struct SQueryProfileSummary {
   int64_t startTs;      // Object created and added into the message queue
   int64_t endTs;        // the timestamp when the task is completed
@@ -84,7 +79,7 @@ typedef struct SSchedulerReq {
 } SSchedulerReq;
 
 
-int32_t schedulerInit(SSchedulerCfg *cfg);
+int32_t schedulerInit(void);
 
 int32_t schedulerExecJob(SSchedulerReq *pReq, int64_t *pJob);
 
@@ -96,6 +91,8 @@ int32_t schedulerGetTasksStatus(int64_t job, SArray *pSub);
 
 void schedulerStopQueryHb(void *pTrans);
 
+int32_t schedulerUpdatePolicy(int32_t policy);
+int32_t schedulerEnableReSchedule(bool enableResche);
 
 /**
  * Cancel query job
diff --git a/source/client/src/clientEnv.c b/source/client/src/clientEnv.c
index 9e67dc6571aae2401bda0a18f348a602dad1790d..da9d63fdfd6cd9cd6879130a20838a009c11e1de 100644
--- a/source/client/src/clientEnv.c
+++ b/source/client/src/clientEnv.c
@@ -363,8 +363,7 @@ void taos_init_imp(void) {
   SCatalogCfg cfg = {.maxDBCacheNum = 100, .maxTblCacheNum = 100};
   catalogInit(&cfg);
 
-  SSchedulerCfg scfg = {.maxJobNum = 100};
-  schedulerInit(&scfg);
+  schedulerInit();
   tscDebug("starting to initialize TAOS driver");
 
   taosSetCoreDump(true);
diff --git a/source/client/src/clientImpl.c b/source/client/src/clientImpl.c
index 04d6df3be01a707c55369c46059c98152a7dc2cc..5e620d106045f341af6ed1dde9653abd1da9ea4e 100644
--- a/source/client/src/clientImpl.c
+++ b/source/client/src/clientImpl.c
@@ -834,6 +834,7 @@ void schedulerExecCb(SExecResult* pResult, void* param, int32_t code) {
     tscDebug("0x%" PRIx64 " client retry to handle the error, code:%d - %s, tryCount:%d, reqId:0x%" PRIx64,
              pRequest->self, code, tstrerror(code), pRequest->retry, pRequest->requestId);
     pRequest->prevCode = code;
+    schedulerFreeJob(&pRequest->body.queryJob, 0);
     doAsyncQuery(pRequest, true);
     return;
   }
diff --git a/source/client/src/clientMain.c b/source/client/src/clientMain.c
index 6ab16b722e79dcdabc26cdf7c0bad25c6d3e6326..62052457fd61d8e0f408ef9c0d5cb0b5c6cc702d 100644
--- a/source/client/src/clientMain.c
+++ b/source/client/src/clientMain.c
@@ -131,6 +131,7 @@ void taos_close(TAOS *taos) {
 
   STscObj *pObj = acquireTscObj(*(int64_t *)taos);
   if (NULL == pObj) {
+    taosMemoryFree(taos);
     return;
   }
 
diff --git a/source/libs/command/CMakeLists.txt b/source/libs/command/CMakeLists.txt
index 51118f4a34be578a62ae9ec4de0f02cb7fbabb6b..a890972d149531d01620cebc9f0ca2db0166fd38 100644
--- a/source/libs/command/CMakeLists.txt
+++ b/source/libs/command/CMakeLists.txt
@@ -8,9 +8,9 @@ target_include_directories(
 
 target_link_libraries(
         command
-        PRIVATE os util nodes catalog function transport qcom
+        PRIVATE os util nodes catalog function transport qcom scheduler
 )
 
 if(${BUILD_TEST})
     ADD_SUBDIRECTORY(test)
-endif(${BUILD_TEST})
\ No newline at end of file
+endif(${BUILD_TEST})
diff --git a/source/libs/command/inc/commandInt.h b/source/libs/command/inc/commandInt.h
index 6aca581f45d186e76ab2c4b38a86f2851dd6810e..7012c889e9d216433342d785d207a5ecfc7d129b 100644
--- a/source/libs/command/inc/commandInt.h
+++ b/source/libs/command/inc/commandInt.h
@@ -77,6 +77,10 @@ extern "C" {
 #define EXPLAIN_MODE_FORMAT "mode=%s"
 #define EXPLAIN_STRING_TYPE_FORMAT "%s"
 
+#define COMMAND_RESET_LOG "resetLog"
+#define COMMAND_SCHEDULE_POLICY "schedulePolicy"
+#define COMMAND_ENABLE_RESCHEDULE "enableReSchedule"
+
 typedef struct SExplainGroup {
   int32_t   nodeNum;
   int32_t   physiPlanExecNum;
diff --git a/source/libs/command/src/command.c b/source/libs/command/src/command.c
index 034778e5bfd4f527ca4782d7e91015244db8b012..d22b3d88b4f33c1401e29a05726f92086c21f633 100644
--- a/source/libs/command/src/command.c
+++ b/source/libs/command/src/command.c
@@ -17,6 +17,8 @@
 #include "catalog.h"
 #include "tdatablock.h"
 #include "tglobal.h"
+#include "commandInt.h"
+#include "scheduler.h"
 
 extern SConfig* tsCfg;
 
@@ -479,7 +481,42 @@ static int32_t execShowCreateSTable(SShowCreateTableStmt* pStmt, SRetrieveTableR
   return execShowCreateTable(pStmt, pRsp);
 }
 
+static int32_t execAlterCmd(char* cmd, char* value, bool* processed) {
+  int32_t code = 0;
+  
+  if (0 == strcasecmp(cmd, COMMAND_RESET_LOG)) {
+    taosResetLog();
+    cfgDumpCfg(tsCfg, 0, false);
+  } else if (0 == strcasecmp(cmd, COMMAND_SCHEDULE_POLICY)) {
+    code = schedulerUpdatePolicy(atoi(value));
+  } else if (0 == strcasecmp(cmd, COMMAND_ENABLE_RESCHEDULE)) {
+    code = schedulerEnableReSchedule(atoi(value));
+  } else {
+    goto _return;
+  }
+
+  *processed = true;
+
+_return:
+
+  if (code) {
+    terrno = code;
+  }
+  
+  return code;  
+}
+
 static int32_t execAlterLocal(SAlterLocalStmt* pStmt) {
+  bool processed = false;
+  
+  if (execAlterCmd(pStmt->config, pStmt->value, &processed)) {
+    return terrno;
+  }
+
+  if (processed) {
+    goto _return;
+  }
+  
   if (cfgSetItem(tsCfg, pStmt->config, pStmt->value, CFG_STYPE_ALTER_CMD)) {
     return terrno;
   }
@@ -488,6 +525,8 @@ static int32_t execAlterLocal(SAlterLocalStmt* pStmt) {
     return terrno;
   }
 
+_return:
+
   return TSDB_CODE_SUCCESS;
 }
 
diff --git a/source/libs/nodes/src/nodesUtilFuncs.c b/source/libs/nodes/src/nodesUtilFuncs.c
index b00b08a66d4835f0a01fdde843582910b0ac8f3d..7265e7ee7802081b37c04dbc774532ea56e73883 100644
--- a/source/libs/nodes/src/nodesUtilFuncs.c
+++ b/source/libs/nodes/src/nodesUtilFuncs.c
@@ -388,6 +388,11 @@ static void destroyDataSinkNode(SDataSinkNode* pNode) { nodesDestroyNode((SNode*
 
 static void destroyExprNode(SExprNode* pExpr) { taosArrayDestroy(pExpr->pAssociation); }
 
+static void nodesDestroyNodePointer(void* node) {
+  SNode* pNode = *(SNode**)node;
+  nodesDestroyNode(pNode);
+}
+
 void nodesDestroyNode(SNode* pNode) {
   if (NULL == pNode) {
     return;
@@ -718,6 +723,7 @@ void nodesDestroyNode(SNode* pNode) {
       }
       taosArrayDestroy(pQuery->pDbList);
       taosArrayDestroy(pQuery->pTableList);
+      taosArrayDestroyEx(pQuery->pPlaceholderValues, nodesDestroyNodePointer);
       break;
     }
     case QUERY_NODE_LOGIC_PLAN_SCAN: {
diff --git a/source/libs/qworker/inc/qwInt.h b/source/libs/qworker/inc/qwInt.h
index 539643c3907cc20de3bee586d21135fbe8adb748..d8d7c5a0ea82543118e9570c3ce9358d01ff49bf 100644
--- a/source/libs/qworker/inc/qwInt.h
+++ b/source/libs/qworker/inc/qwInt.h
@@ -378,6 +378,7 @@ void qwDbgDumpMgmtInfo(SQWorker *mgmt);
 int32_t qwDbgValidateStatus(QW_FPARAMS_DEF, int8_t oriStatus, int8_t newStatus, bool *ignore);
 int32_t qwDbgBuildAndSendRedirectRsp(int32_t rspType, SRpcHandleInfo *pConn, int32_t code, SEpSet *pEpSet);
 int32_t qwAddTaskCtx(QW_FPARAMS_DEF);
+int32_t qwDbgResponseRedirect(SQWMsg *qwMsg, SQWTaskCtx *ctx);
 
 
 #ifdef __cplusplus
diff --git a/source/libs/qworker/inc/qwMsg.h b/source/libs/qworker/inc/qwMsg.h
index 704cd3142845c07976f1d8a4b8a798bc99e775d3..acb7004a510cb171562cbe94775f5149fabc7847 100644
--- a/source/libs/qworker/inc/qwMsg.h
+++ b/source/libs/qworker/inc/qwMsg.h
@@ -24,7 +24,7 @@ extern "C" {
 #include "dataSinkMgt.h"
 
 int32_t qwAbortPrerocessQuery(QW_FPARAMS_DEF);
-int32_t qwPrerocessQuery(QW_FPARAMS_DEF, SQWMsg *qwMsg);
+int32_t qwPreprocessQuery(QW_FPARAMS_DEF, SQWMsg *qwMsg);
 int32_t qwProcessQuery(QW_FPARAMS_DEF, SQWMsg *qwMsg, const char* sql);
 int32_t qwProcessCQuery(QW_FPARAMS_DEF, SQWMsg *qwMsg);
 int32_t qwProcessReady(QW_FPARAMS_DEF, SQWMsg *qwMsg);
diff --git a/source/libs/qworker/src/qwDbg.c b/source/libs/qworker/src/qwDbg.c
index 869eedf8f6e4970f548300b33b10c8bba246d92e..fa63cf2c3ae16d424ac702b7ef47fadadcc14235 100644
--- a/source/libs/qworker/src/qwDbg.c
+++ b/source/libs/qworker/src/qwDbg.c
@@ -9,7 +9,7 @@
 #include "tmsg.h"
 #include "tname.h"
 
-SQWDebug     gQWDebug = {.statusEnable = true, .dumpEnable = false, .tmp = true};
+SQWDebug     gQWDebug = {.statusEnable = true, .dumpEnable = false, .tmp = false};
 
 int32_t qwDbgValidateStatus(QW_FPARAMS_DEF, int8_t oriStatus, int8_t newStatus, bool *ignore) {
   if (!gQWDebug.statusEnable) {
@@ -147,9 +147,9 @@ int32_t qwDbgBuildAndSendRedirectRsp(int32_t rspType, SRpcHandleInfo *pConn, int
   return TSDB_CODE_SUCCESS;
 }
 
-int32_t qwDbgResponseREdirect(SQWMsg *qwMsg, SQWTaskCtx *ctx) {
+int32_t qwDbgResponseRedirect(SQWMsg *qwMsg, SQWTaskCtx *ctx) {
   if (gQWDebug.tmp) {
-    if (TDMT_SCH_QUERY == qwMsg->msgType) {
+    if (TDMT_SCH_QUERY == qwMsg->msgType && (0 == taosRand() % 3)) {
       SEpSet epSet = {0};
       epSet.inUse = 1;
       epSet.numOfEps = 3;
@@ -159,16 +159,15 @@ int32_t qwDbgResponseREdirect(SQWMsg *qwMsg, SQWTaskCtx *ctx) {
       epSet.eps[1].port = 7200;
       strcpy(epSet.eps[2].fqdn, "localhost");
       epSet.eps[2].port = 7300;
-      
+
+      ctx->phase = QW_PHASE_POST_QUERY;      
       qwDbgBuildAndSendRedirectRsp(qwMsg->msgType + 1, &qwMsg->connInfo, TSDB_CODE_RPC_REDIRECT, &epSet);
-      gQWDebug.tmp = false;
       return TSDB_CODE_SUCCESS;
     }
     
-    if (TDMT_SCH_MERGE_QUERY == qwMsg->msgType) {
+    if (TDMT_SCH_MERGE_QUERY == qwMsg->msgType && (0 == taosRand() % 3)) {
       ctx->phase = QW_PHASE_POST_QUERY;
       qwDbgBuildAndSendRedirectRsp(qwMsg->msgType + 1, &qwMsg->connInfo, TSDB_CODE_RPC_REDIRECT, NULL);
-      gQWDebug.tmp = false;
       return TSDB_CODE_SUCCESS;
     }
   }
diff --git a/source/libs/qworker/src/qwMsg.c b/source/libs/qworker/src/qwMsg.c
index 73110472f7e35e71ee4bf478c422664212e9660c..93268e1bccd35640660f911f07c8066effbd07bf 100644
--- a/source/libs/qworker/src/qwMsg.c
+++ b/source/libs/qworker/src/qwMsg.c
@@ -315,10 +315,10 @@ int32_t qWorkerPreprocessQueryMsg(void *qWorkerMgmt, SRpcMsg *pMsg) {
   int64_t  rId = msg->refId;
   int32_t  eId = msg->execId;
 
-  SQWMsg qwMsg = {.msg = msg->msg + msg->sqlLen, .msgLen = msg->phyLen, .connInfo = pMsg->info};
+  SQWMsg qwMsg = {.msgType = pMsg->msgType, .msg = msg->msg + msg->sqlLen, .msgLen = msg->phyLen, .connInfo = pMsg->info};
 
   QW_SCH_TASK_DLOG("prerocessQuery start, handle:%p", pMsg->info.handle);
-  QW_ERR_RET(qwPrerocessQuery(QW_FPARAMS(), &qwMsg));
+  QW_ERR_RET(qwPreprocessQuery(QW_FPARAMS(), &qwMsg));
   QW_SCH_TASK_DLOG("prerocessQuery end, handle:%p", pMsg->info.handle);
 
   return TSDB_CODE_SUCCESS;
diff --git a/source/libs/qworker/src/qworker.c b/source/libs/qworker/src/qworker.c
index 3e8ced318c4baa2f1eec3aee85db03c6c67547ba..1b58dc28244fce3971392ecdcda66aec4d4ed876 100644
--- a/source/libs/qworker/src/qworker.c
+++ b/source/libs/qworker/src/qworker.c
@@ -469,7 +469,7 @@ int32_t qwAbortPrerocessQuery(QW_FPARAMS_DEF) {
 }
 
 
-int32_t qwPrerocessQuery(QW_FPARAMS_DEF, SQWMsg *qwMsg) {
+int32_t qwPreprocessQuery(QW_FPARAMS_DEF, SQWMsg *qwMsg) {
   int32_t        code = 0;
   bool           queryRsped = false;
   SSubplan      *plan = NULL;
@@ -488,6 +488,8 @@ int32_t qwPrerocessQuery(QW_FPARAMS_DEF, SQWMsg *qwMsg) {
 
   QW_ERR_JRET(qwAddTaskStatus(QW_FPARAMS(), JOB_TASK_STATUS_INIT));
 
+  qwDbgResponseRedirect(qwMsg, ctx);
+
 _return:
 
   if (ctx) {
diff --git a/source/libs/scheduler/inc/schInt.h b/source/libs/scheduler/inc/schInt.h
index b6b17cb1066e738e360bd7a8cd2d80c5b0d7def3..bc0270635d237df97b88823c0ea7a6badf2493d8 100644
--- a/source/libs/scheduler/inc/schInt.h
+++ b/source/libs/scheduler/inc/schInt.h
@@ -28,15 +28,6 @@ extern "C" {
 #include "trpc.h"
 #include "command.h"
 
-#define SCHEDULE_DEFAULT_MAX_JOB_NUM 1000
-#define SCHEDULE_DEFAULT_MAX_TASK_NUM 1000
-#define SCHEDULE_DEFAULT_MAX_NODE_TABLE_NUM 200  // unit is TSDB_TABLE_NUM_UNIT
-
-#define SCH_DEFAULT_TASK_TIMEOUT_USEC 10000000
-#define SCH_MAX_TASK_TIMEOUT_USEC 60000000
-
-#define SCH_MAX_CANDIDATE_EP_NUM TSDB_MAX_REPLICA
-
 enum {
   SCH_READ = 1,
   SCH_WRITE,
@@ -54,6 +45,24 @@ typedef enum {
   SCH_OP_GET_STATUS,
 } SCH_OP_TYPE;
 
+typedef enum {
+  SCH_LOAD_SEQ = 1,
+  SCH_RANDOM,
+  SCH_ALL,
+} SCH_POLICY;
+
+#define SCHEDULE_DEFAULT_MAX_JOB_NUM 1000
+#define SCHEDULE_DEFAULT_MAX_TASK_NUM 1000
+#define SCHEDULE_DEFAULT_MAX_NODE_TABLE_NUM 200  // unit is TSDB_TABLE_NUM_UNIT
+#define SCHEDULE_DEFAULT_POLICY SCH_LOAD_SEQ
+
+#define SCH_DEFAULT_TASK_TIMEOUT_USEC 10000000
+#define SCH_MAX_TASK_TIMEOUT_USEC 60000000
+#define SCH_MAX_CANDIDATE_EP_NUM TSDB_MAX_REPLICA
+
+
+
+
 typedef struct SSchDebug {
   bool     lockEnable;
   bool     apiEnable;
@@ -126,6 +135,13 @@ typedef struct SSchStatusFps {
   schStatusEventFp eventFp;
 } SSchStatusFps;
 
+typedef struct SSchedulerCfg {
+  uint32_t   maxJobNum;
+  int32_t    maxNodeTableNum;
+  SCH_POLICY schPolicy;
+  bool       enableReSchedule;
+} SSchedulerCfg;
+
 typedef struct SSchedulerMgmt {
   uint64_t        taskId; // sequential taksId
   uint64_t        sId;    // schedulerId
@@ -184,34 +200,36 @@ typedef struct SSchLevel {
 
 typedef struct SSchTaskProfile {
   int64_t  startTs;
-  int64_t* execTime;
+  SArray*  execTime;
   int64_t  waitTime;
   int64_t  endTs;
 } SSchTaskProfile;
 
 typedef struct SSchTask {
-  uint64_t             taskId;         // task id
-  SRWLatch             lock;           // task reentrant lock
-  int32_t              maxExecTimes;   // task may exec times
-  int32_t              execId;        // task current execute try index
-  SSchLevel           *level;          // level
-  SRWLatch             planLock;       // task update plan lock
-  SSubplan            *plan;           // subplan
-  char                *msg;            // operator tree
-  int32_t              msgLen;         // msg length
-  int8_t               status;         // task status
-  int32_t              lastMsgType;    // last sent msg type
-  int64_t              timeoutUsec;    // taks timeout useconds before reschedule
-  SQueryNodeAddr       succeedAddr;    // task executed success node address
-  int8_t               candidateIdx;   // current try condidation index
-  SArray              *candidateAddrs; // condidate node addresses, element is SQueryNodeAddr
-  SHashObj            *execNodes;      // all tried node for current task, element is SSchNodeInfo
-  SSchTaskProfile      profile;        // task execution profile
-  int32_t              childReady;     // child task ready number
-  SArray              *children;       // the datasource tasks,from which to fetch the result, element is SQueryTask*
-  SArray              *parents;        // the data destination tasks, get data from current task, element is SQueryTask*
-  void*                handle;         // task send handle 
-  bool                 registerdHb;    // registered in hb
+  uint64_t             taskId;          // task id
+  SRWLatch             lock;            // task reentrant lock
+  int32_t              maxExecTimes;    // task max exec times
+  int32_t              maxRetryTimes;   // task max retry times
+  int32_t              retryTimes;      // task retry times
+  int32_t              execId;          // task current execute index
+  SSchLevel           *level;           // level
+  SRWLatch             planLock;        // task update plan lock
+  SSubplan            *plan;            // subplan
+  char                *msg;             // operator tree
+  int32_t              msgLen;          // msg length
+  int8_t               status;          // task status
+  int32_t              lastMsgType;     // last sent msg type
+  int64_t              timeoutUsec;     // task timeout useconds before reschedule
+  SQueryNodeAddr       succeedAddr;     // task executed success node address
+  int8_t               candidateIdx;    // current try condidation index
+  SArray              *candidateAddrs;  // condidate node addresses, element is SQueryNodeAddr
+  SHashObj            *execNodes;       // all tried node for current task, element is SSchNodeInfo
+  SSchTaskProfile      profile;         // task execution profile
+  int32_t              childReady;      // child task ready number
+  SArray              *children;        // the datasource tasks,from which to fetch the result, element is SQueryTask*
+  SArray              *parents;         // the data destination tasks, get data from current task, element is SQueryTask*
+  void*                handle;          // task send handle 
+  bool                 registerdHb;     // registered in hb
 } SSchTask;
 
 typedef struct SSchJobAttr {
@@ -265,7 +283,7 @@ typedef struct SSchJob {
 
 extern SSchedulerMgmt schMgmt;
 
-#define SCH_TASK_TIMEOUT(_task) ((taosGetTimestampUs() - (_task)->profile.execTime[(_task)->execId % (_task)->maxExecTimes]) > (_task)->timeoutUsec)
+#define SCH_TASK_TIMEOUT(_task) ((taosGetTimestampUs() - *(int64_t*)taosArrayGet((_task)->profile.execTime, (_task)->execId)) > (_task)->timeoutUsec)
 
 #define SCH_TASK_READY_FOR_LAUNCH(readyNum, task) ((readyNum) >= taosArrayGetSize((task)->children))
 
@@ -299,7 +317,6 @@ extern SSchedulerMgmt schMgmt;
 #define SCH_TASK_NEED_FLOW_CTRL(_job, _task) (SCH_IS_DATA_BIND_QRY_TASK(_task) && SCH_JOB_NEED_FLOW_CTRL(_job) && SCH_IS_LEVEL_UNFINISHED((_task)->level))
 #define SCH_FETCH_TYPE(_pSrcTask) (SCH_IS_DATA_BIND_QRY_TASK(_pSrcTask) ? TDMT_SCH_FETCH : TDMT_SCH_MERGE_FETCH)
 #define SCH_TASK_NEED_FETCH(_task) ((_task)->plan->subplanType != SUBPLAN_TYPE_MODIFY)
-#define SCH_TASK_MAX_EXEC_TIMES(_levelIdx, _levelNum) (SCH_MAX_CANDIDATE_EP_NUM * ((_levelNum) - (_levelIdx)))
 
 #define SCH_SET_JOB_TYPE(_job, type) do { if ((type) != SUBPLAN_TYPE_MODIFY) { (_job)->attr.queryJob = true; } } while (0)
 #define SCH_IS_QUERY_JOB(_job) ((_job)->attr.queryJob) 
@@ -321,8 +338,7 @@ extern SSchedulerMgmt schMgmt;
 #define SCH_LOG_TASK_START_TS(_task)                          \
   do {                                                        \
     int64_t us = taosGetTimestampUs();                        \
-    int32_t idx = (_task)->execId % (_task)->maxExecTimes; \
-    (_task)->profile.execTime[idx] = us;                    \
+    taosArrayPush((_task)->profile.execTime, &us);           \
     if (0 == (_task)->execId) {                              \
       (_task)->profile.startTs = us;                          \
     }                                                         \
@@ -331,8 +347,7 @@ extern SSchedulerMgmt schMgmt;
 #define SCH_LOG_TASK_WAIT_TS(_task)                        \
   do {                                                    \
     int64_t us = taosGetTimestampUs();                    \
-    int32_t idx = (_task)->execId % (_task)->maxExecTimes; \
-    (_task)->profile.waitTime += us - (_task)->profile.execTime[idx];    \
+    (_task)->profile.waitTime += us - *(int64_t*)taosArrayGet((_task)->profile.execTime, (_task)->execId);    \
   } while (0)  
 
 
@@ -340,7 +355,8 @@ extern SSchedulerMgmt schMgmt;
   do {                                                    \
     int64_t us = taosGetTimestampUs();                    \
     int32_t idx = (_task)->execId % (_task)->maxExecTimes; \
-    (_task)->profile.execTime[idx] = us - (_task)->profile.execTime[idx];    \
+    int64_t *startts = taosArrayGet((_task)->profile.execTime, (_task)->execId); \
+    *startts = us - *startts;                        \
     (_task)->profile.endTs = us;                          \
   } while (0)  
 
@@ -471,9 +487,11 @@ void    schFreeTask(SSchJob *pJob, SSchTask *pTask);
 void    schDropTaskInHashList(SSchJob *pJob, SHashObj *list);
 int32_t schLaunchLevelTasks(SSchJob *pJob, SSchLevel *level);
 int32_t schGetTaskFromList(SHashObj *pTaskList, uint64_t taskId, SSchTask **pTask);
-int32_t schInitTask(SSchJob *pJob, SSchTask *pTask, SSubplan *pPlan, SSchLevel *pLevel, int32_t levelNum);
+int32_t schInitTask(SSchJob *pJob, SSchTask *pTask, SSubplan *pPlan, SSchLevel *pLevel);
 int32_t schSwitchTaskCandidateAddr(SSchJob *pJob, SSchTask *pTask);
 void    schDirectPostJobRes(SSchedulerReq* pReq, int32_t errCode);
+int32_t schHandleJobFailure(SSchJob *pJob, int32_t errCode);
+int32_t schHandleJobDrop(SSchJob *pJob, int32_t errCode);
 bool    schChkCurrentOp(SSchJob *pJob, int32_t op, bool sync);
 
 extern SSchDebug gSCHDebug;
diff --git a/source/libs/scheduler/src/schJob.c b/source/libs/scheduler/src/schJob.c
index 19bb93249f50d22bb535e25654fc93bbab11a981..1b1268baf1bb58e9fcf51ccef36dac8afe0f6a53 100644
--- a/source/libs/scheduler/src/schJob.c
+++ b/source/libs/scheduler/src/schJob.c
@@ -343,7 +343,7 @@ int32_t schValidateAndBuildJob(SQueryPlan *pDag, SSchJob *pJob) {
         SCH_ERR_JRET(TSDB_CODE_QRY_OUT_OF_MEMORY);
       }
 
-      SCH_ERR_JRET(schInitTask(pJob, pTask, plan, pLevel, levelNum));
+      SCH_ERR_JRET(schInitTask(pJob, pTask, plan, pLevel));
 
       SCH_ERR_JRET(schAppendJobDataSrc(pJob, pTask));
 
@@ -476,7 +476,7 @@ _return:
   SCH_UNLOCK(SCH_WRITE, &pJob->opStatus.lock);
 }
 
-int32_t schProcessOnJobFailureImpl(SSchJob *pJob, int32_t status, int32_t errCode) {
+int32_t schProcessOnJobFailure(SSchJob *pJob, int32_t errCode) {
   schUpdateJobErrCode(pJob, errCode);
   
   int32_t code = atomic_load_32(&pJob->errCode);
@@ -489,21 +489,29 @@ int32_t schProcessOnJobFailureImpl(SSchJob *pJob, int32_t status, int32_t errCod
   SCH_RET(TSDB_CODE_SCH_IGNORE_ERROR);
 }
 
-// Note: no more task error processing, handled in function internal
-int32_t schProcessOnJobFailure(SSchJob *pJob, int32_t errCode) {
+int32_t schHandleJobFailure(SSchJob *pJob, int32_t errCode) {
   if (TSDB_CODE_SCH_IGNORE_ERROR == errCode) {
     return TSDB_CODE_SCH_IGNORE_ERROR;
   }
 
-  schProcessOnJobFailureImpl(pJob, JOB_TASK_STATUS_FAIL, errCode);
+  schSwitchJobStatus(pJob, JOB_TASK_STATUS_FAIL, &errCode);
   return TSDB_CODE_SCH_IGNORE_ERROR;
 }
 
-// Note: no more error processing, handled in function internal
 int32_t schProcessOnJobDropped(SSchJob *pJob, int32_t errCode) {
-  SCH_RET(schProcessOnJobFailureImpl(pJob, JOB_TASK_STATUS_DROP, errCode));
+  SCH_RET(schProcessOnJobFailure(pJob, errCode));
+}
+
+int32_t schHandleJobDrop(SSchJob *pJob, int32_t errCode) {
+  if (TSDB_CODE_SCH_IGNORE_ERROR == errCode) {
+    return TSDB_CODE_SCH_IGNORE_ERROR;
+  }
+
+  schSwitchJobStatus(pJob, JOB_TASK_STATUS_DROP, &errCode);
+  return TSDB_CODE_SCH_IGNORE_ERROR;
 }
 
+
 int32_t schProcessOnJobPartialSuccess(SSchJob *pJob) {
   schPostJobRes(pJob, SCH_OP_EXEC);
 
@@ -828,7 +836,7 @@ void schProcessOnOpEnd(SSchJob *pJob, SCH_OP_TYPE type, SSchedulerReq* pReq, int
   }
 
   if (errCode) {
-    schSwitchJobStatus(pJob, JOB_TASK_STATUS_FAIL, (void*)&errCode);
+    schHandleJobFailure(pJob, errCode);
   }
 
   SCH_JOB_DLOG("job end %s operation with code %s", schGetOpStr(type), tstrerror(errCode));
@@ -907,7 +915,7 @@ void schProcessOnCbEnd(SSchJob *pJob, SSchTask *pTask, int32_t errCode) {
   }
 
   if (errCode) {
-    schSwitchJobStatus(pJob, JOB_TASK_STATUS_FAIL, (void*)&errCode);
+    schHandleJobFailure(pJob, errCode);
   }
   
   if (pJob) {
diff --git a/source/libs/scheduler/src/schTask.c b/source/libs/scheduler/src/schTask.c
index 236257666b23b93d174f8f1126497f061dfd90c9..9483ecd6ebfbfd17d301280eed0191b6c26b6255 100644
--- a/source/libs/scheduler/src/schTask.c
+++ b/source/libs/scheduler/src/schTask.c
@@ -42,32 +42,47 @@ void schFreeTask(SSchJob *pJob, SSchTask *pTask) {
     taosHashCleanup(pTask->execNodes);
   }
 
-  taosMemoryFree(pTask->profile.execTime);
+  taosArrayDestroy(pTask->profile.execTime);
 }
 
-int32_t schInitTask(SSchJob *pJob, SSchTask *pTask, SSubplan *pPlan, SSchLevel *pLevel, int32_t levelNum) {
+void schInitTaskRetryTimes(SSchJob *pJob, SSchTask *pTask, SSchLevel *pLevel) {
+  if (SCH_IS_DATA_BIND_TASK(pTask) || (!SCH_IS_QUERY_JOB(pJob)) || (SCH_ALL != schMgmt.cfg.schPolicy)) {
+    pTask->maxRetryTimes = SCH_MAX_CANDIDATE_EP_NUM;
+  } else {
+    int32_t nodeNum = taosArrayGetSize(pJob->nodeList);
+    pTask->maxRetryTimes = TMAX(nodeNum, SCH_MAX_CANDIDATE_EP_NUM);
+  }
+  
+  pTask->maxExecTimes = pTask->maxRetryTimes * (pLevel->level + 1);
+}
+
+int32_t schInitTask(SSchJob *pJob, SSchTask *pTask, SSubplan *pPlan, SSchLevel *pLevel) {
   int32_t code = 0;
 
   pTask->plan = pPlan;
   pTask->level = pLevel;
   pTask->execId = -1;
-  pTask->maxExecTimes = SCH_TASK_MAX_EXEC_TIMES(pLevel->level, levelNum);
   pTask->timeoutUsec = SCH_DEFAULT_TASK_TIMEOUT_USEC;
   pTask->taskId = schGenTaskId();
   pTask->execNodes =
       taosHashInit(SCH_MAX_CANDIDATE_EP_NUM, taosGetDefaultHashFunction(TSDB_DATA_TYPE_INT), true, HASH_NO_LOCK);
-  pTask->profile.execTime = taosMemoryCalloc(pTask->maxExecTimes, sizeof(int64_t));
+
+  schInitTaskRetryTimes(pJob, pTask, pLevel);
+
+  pTask->profile.execTime = taosArrayInit(pTask->maxExecTimes, sizeof(int64_t));
   if (NULL == pTask->execNodes || NULL == pTask->profile.execTime) {
     SCH_ERR_JRET(TSDB_CODE_QRY_OUT_OF_MEMORY);
   }
 
   SCH_SET_TASK_STATUS(pTask, JOB_TASK_STATUS_INIT);
 
+  SCH_TASK_DLOG("task initialized, max times %d:%d", pTask->maxRetryTimes, pTask->maxExecTimes);
+
   return TSDB_CODE_SUCCESS;
 
 _return:
 
-  taosMemoryFreeClear(pTask->profile.execTime);
+  taosArrayDestroy(pTask->profile.execTime);
   taosHashCleanup(pTask->execNodes);
 
   SCH_RET(code);
@@ -105,7 +120,7 @@ int32_t schDropTaskExecNode(SSchJob *pJob, SSchTask *pTask, void *handle, int32_
   }
 
   if (taosHashRemove(pTask->execNodes, &execId, sizeof(execId))) {
-    SCH_TASK_ELOG("fail to remove execId %d from execNodeList", execId);
+    SCH_TASK_DLOG("execId %d already not in execNodeList", execId);
   } else {
     SCH_TASK_DLOG("execId %d removed from execNodeList", execId);
   }
@@ -235,7 +250,7 @@ int32_t schProcessOnTaskSuccess(SSchJob *pJob, SSchTask *pTask) {
       }
 
       if (pTask->level->taskFailed > 0) {
-        SCH_RET(schSwitchJobStatus(pJob, JOB_TASK_STATUS_FAIL, NULL));
+        SCH_RET(schHandleJobFailure(pJob, pJob->errCode));
       } else {
         SCH_RET(schSwitchJobStatus(pJob, JOB_TASK_STATUS_PART_SUCC, NULL));
       }
@@ -285,6 +300,10 @@ int32_t schProcessOnTaskSuccess(SSchJob *pJob, SSchTask *pTask) {
 }
 
 int32_t schRescheduleTask(SSchJob *pJob, SSchTask *pTask) {
+  if (!schMgmt.cfg.enableReSchedule) {
+    return TSDB_CODE_SUCCESS;
+  }
+  
   if (SCH_IS_DATA_BIND_TASK(pTask)) {
     return TSDB_CODE_SUCCESS;
   }
@@ -304,13 +323,17 @@ int32_t schRescheduleTask(SSchJob *pJob, SSchTask *pTask) {
 int32_t schDoTaskRedirect(SSchJob *pJob, SSchTask *pTask, SDataBuf *pData, int32_t rspCode) {
   int32_t code = 0;
 
-  if ((pTask->execId + 1) >= pTask->maxExecTimes) {
-    SCH_TASK_DLOG("task no more retry since reach max try times, execId:%d", pTask->execId);
-    schSwitchJobStatus(pJob, JOB_TASK_STATUS_FAIL, (void *)&rspCode);
-    return TSDB_CODE_SUCCESS;
+  SCH_TASK_DLOG("task will be redirected now, status:%s", SCH_GET_TASK_STATUS_STR(pTask));
+
+  if (NULL == pData) {
+    pTask->retryTimes = 0;
   }
 
-  SCH_TASK_DLOG("task will be redirected now, status:%s", SCH_GET_TASK_STATUS_STR(pTask));
+  if (((pTask->execId + 1) >= pTask->maxExecTimes) || ((pTask->retryTimes + 1) > pTask->maxRetryTimes)) {
+    SCH_TASK_DLOG("task no more retry since reach max times %d:%d, execId %d", pTask->maxRetryTimes, pTask->maxExecTimes, pTask->execId);
+    schHandleJobFailure(pJob, rspCode);
+    return TSDB_CODE_SUCCESS;
+  }
 
   schDropTaskOnExecNode(pJob, pTask);
   taosHashClear(pTask->execNodes);
@@ -493,9 +516,15 @@ int32_t schTaskCheckSetRetry(SSchJob *pJob, SSchTask *pTask, int32_t errCode, bo
     }
   }
 
+  if ((pTask->retryTimes + 1) > pTask->maxRetryTimes) {
+    *needRetry = false;
+    SCH_TASK_DLOG("task no more retry since reach max retry times, retryTimes:%d/%d", pTask->retryTimes, pTask->maxRetryTimes);
+    return TSDB_CODE_SUCCESS;
+  }
+
   if ((pTask->execId + 1) >= pTask->maxExecTimes) {
     *needRetry = false;
-    SCH_TASK_DLOG("task no more retry since reach max try times, execId:%d", pTask->execId);
+    SCH_TASK_DLOG("task no more retry since reach max exec times, execId:%d/%d", pTask->execId, pTask->maxExecTimes);
     return TSDB_CODE_SUCCESS;
   }
 
@@ -649,10 +678,31 @@ int32_t schUpdateTaskCandidateAddr(SSchJob *pJob, SSchTask *pTask, SEpSet *pEpSe
 
 int32_t schSwitchTaskCandidateAddr(SSchJob *pJob, SSchTask *pTask) {
   int32_t candidateNum = taosArrayGetSize(pTask->candidateAddrs);
-  if (++pTask->candidateIdx >= candidateNum) {
-    pTask->candidateIdx = 0;
+  if (candidateNum <= 1) {
+    goto _return;
+  }
+  
+  switch (schMgmt.cfg.schPolicy) {
+    case SCH_LOAD_SEQ:
+    case SCH_ALL: 
+    default:
+      if (++pTask->candidateIdx >= candidateNum) {
+        pTask->candidateIdx = 0;
+      }
+      break;
+    case SCH_RANDOM: {
+      int32_t lastIdx = pTask->candidateIdx;
+      while (lastIdx == pTask->candidateIdx) {
+        pTask->candidateIdx = taosRand() % candidateNum;
+      }
+      break;
+    }
   }
-  SCH_TASK_DLOG("switch task candiateIdx to %d", pTask->candidateIdx);
+
+_return:
+
+  SCH_TASK_DLOG("switch task candiateIdx to %d/%d", pTask->candidateIdx, candidateNum);
+  
   return TSDB_CODE_SUCCESS;
 }
 
@@ -739,8 +789,9 @@ int32_t schLaunchTaskImpl(SSchJob *pJob, SSchTask *pTask) {
 
   atomic_add_fetch_32(&pTask->level->taskLaunchedNum, 1);
   pTask->execId++;
+  pTask->retryTimes++;
 
-  SCH_TASK_DLOG("start to launch task's %dth exec", pTask->execId);
+  SCH_TASK_DLOG("start to launch task, execId %d, retry %d", pTask->execId, pTask->retryTimes);
 
   SCH_LOG_TASK_START_TS(pTask);
 
diff --git a/source/libs/scheduler/src/scheduler.c b/source/libs/scheduler/src/scheduler.c
index 39465f3064e9b117ca97c345223b17ce83e95a3d..3a15523040f7c0c108273563c17f8000c43ff582 100644
--- a/source/libs/scheduler/src/scheduler.c
+++ b/source/libs/scheduler/src/scheduler.c
@@ -22,26 +22,19 @@ SSchedulerMgmt schMgmt = {
     .jobRef = -1,
 };
 
-int32_t schedulerInit(SSchedulerCfg *cfg) {
+int32_t schedulerInit() {
   if (schMgmt.jobRef >= 0) {
     qError("scheduler already initialized");
     return TSDB_CODE_QRY_INVALID_INPUT;
   }
 
-  if (cfg) {
-    schMgmt.cfg = *cfg;
-
-    if (schMgmt.cfg.maxJobNum == 0) {
-      schMgmt.cfg.maxJobNum = SCHEDULE_DEFAULT_MAX_JOB_NUM;
-    }
-    if (schMgmt.cfg.maxNodeTableNum <= 0) {
-      schMgmt.cfg.maxNodeTableNum = SCHEDULE_DEFAULT_MAX_NODE_TABLE_NUM;
-    }
-  } else {
-    schMgmt.cfg.maxJobNum = SCHEDULE_DEFAULT_MAX_JOB_NUM;
-    schMgmt.cfg.maxNodeTableNum = SCHEDULE_DEFAULT_MAX_NODE_TABLE_NUM;
-  }
+  schMgmt.cfg.maxJobNum = SCHEDULE_DEFAULT_MAX_JOB_NUM;
+  schMgmt.cfg.maxNodeTableNum = SCHEDULE_DEFAULT_MAX_NODE_TABLE_NUM;
+  schMgmt.cfg.schPolicy = SCHEDULE_DEFAULT_POLICY;
+  schMgmt.cfg.enableReSchedule = true;
 
+  qDebug("schedule policy init to %d", schMgmt.cfg.schPolicy);
+  
   schMgmt.jobRef = taosOpenRef(schMgmt.cfg.maxJobNum, schFreeJobImpl);
   if (schMgmt.jobRef < 0) {
     qError("init schduler jobRef failed, num:%u", schMgmt.cfg.maxJobNum);
@@ -130,6 +123,26 @@ void schedulerStopQueryHb(void *pTrans) {
   schCleanClusterHb(pTrans);
 }
 
+int32_t schedulerUpdatePolicy(int32_t policy) {
+  switch (policy) {
+    case SCH_LOAD_SEQ:
+    case SCH_RANDOM:
+    case SCH_ALL:
+      schMgmt.cfg.schPolicy = policy;
+      qDebug("schedule policy updated to %d", schMgmt.cfg.schPolicy);
+      break;
+    default:
+      return TSDB_CODE_TSC_INVALID_INPUT;
+  }
+
+  return TSDB_CODE_SUCCESS;
+}
+
+int32_t schedulerEnableReSchedule(bool enableResche) {
+  schMgmt.cfg.enableReSchedule = enableResche;
+  return TSDB_CODE_SUCCESS;
+}
+
 void schedulerFreeJob(int64_t* jobId, int32_t errCode) {
   if (0 == *jobId) {
     return;
@@ -141,7 +154,7 @@ void schedulerFreeJob(int64_t* jobId, int32_t errCode) {
     return;
   }
 
-  schSwitchJobStatus(pJob, JOB_TASK_STATUS_DROP, (void*)&errCode);
+  schHandleJobDrop(pJob, errCode);
   
   schReleaseJob(*jobId);
   *jobId = 0;
diff --git a/source/libs/scheduler/test/schedulerTests.cpp b/source/libs/scheduler/test/schedulerTests.cpp
index d6b1baf978bdc823b3337e80830ec89f5de4e790..ca2122ed8f433c4b8dd70eb120e0eba972dda9fe 100644
--- a/source/libs/scheduler/test/schedulerTests.cpp
+++ b/source/libs/scheduler/test/schedulerTests.cpp
@@ -477,7 +477,7 @@ void* schtRunJobThread(void *aa) {
   schtInitLogFile();
 
   
-  int32_t code = schedulerInit(NULL);
+  int32_t code = schedulerInit();
   assert(code == 0);
 
 
@@ -649,7 +649,7 @@ TEST(queryTest, normalCase) {
   qnodeAddr.port = 6031;
   taosArrayPush(qnodeList, &qnodeAddr);
   
-  int32_t code = schedulerInit(NULL);
+  int32_t code = schedulerInit();
   ASSERT_EQ(code, 0);
 
   schtBuildQueryDag(&dag);
@@ -756,7 +756,7 @@ TEST(queryTest, readyFirstCase) {
   qnodeAddr.port = 6031;
   taosArrayPush(qnodeList, &qnodeAddr);
   
-  int32_t code = schedulerInit(NULL);
+  int32_t code = schedulerInit();
   ASSERT_EQ(code, 0);
 
   schtBuildQueryDag(&dag);
@@ -866,7 +866,7 @@ TEST(queryTest, flowCtrlCase) {
   qnodeAddr.port = 6031;
   taosArrayPush(qnodeList, &qnodeAddr);
   
-  int32_t code = schedulerInit(NULL);
+  int32_t code = schedulerInit();
   ASSERT_EQ(code, 0);
 
   schtBuildQueryFlowCtrlDag(&dag);
@@ -975,7 +975,7 @@ TEST(insertTest, normalCase) {
   qnodeAddr.port = 6031;
   taosArrayPush(qnodeList, &qnodeAddr);
   
-  int32_t code = schedulerInit(NULL);
+  int32_t code = schedulerInit();
   ASSERT_EQ(code, 0);
 
   schtBuildInsertDag(&dag);
diff --git a/source/util/src/terror.c b/source/util/src/terror.c
index 2364c53a9abd9c15a858e912eeb856d44e25474d..95334b553579b9f8f45b6c152479207e71317754 100644
--- a/source/util/src/terror.c
+++ b/source/util/src/terror.c
@@ -135,7 +135,7 @@ TAOS_DEFINE_ERROR(TSDB_CODE_TSC_STMT_API_ERROR,           "Stmt API usage error"
 TAOS_DEFINE_ERROR(TSDB_CODE_TSC_STMT_TBNAME_ERROR,        "Stmt table name not set")
 TAOS_DEFINE_ERROR(TSDB_CODE_TSC_STMT_CLAUSE_ERROR,        "not supported stmt clause")
 TAOS_DEFINE_ERROR(TSDB_CODE_TSC_QUERY_KILLED,             "Query killed")
-TAOS_DEFINE_ERROR(TSDB_CODE_TSC_NO_EXEC_NODE,             "No available execution node")
+TAOS_DEFINE_ERROR(TSDB_CODE_TSC_NO_EXEC_NODE,             "No available execution node in current query policy configuration")
 TAOS_DEFINE_ERROR(TSDB_CODE_TSC_NOT_STABLE_ERROR,         "Table is not a super table")
 
 // mnode-common
diff --git a/tests/script/api/batchprepare.c b/tests/script/api/batchprepare.c
index b31c39718ca9addbf4e8e2980d57665bb3d19156..29c1fdb015689db8c2bd700adde4112dafe48e0b 100644
--- a/tests/script/api/batchprepare.c
+++ b/tests/script/api/batchprepare.c
@@ -2685,6 +2685,8 @@ int main(int argc, char *argv[])
 
   runAll(taos);
 
+  taos_close(taos);
+
   return 0;
 }