diff --git a/include/common/tmsg.h b/include/common/tmsg.h
index 820f0fbe8d..935e2f6626 100644
--- a/include/common/tmsg.h
+++ b/include/common/tmsg.h
@@ -1294,6 +1294,14 @@ typedef struct {
 int32_t tSerializeSDCreateMnodeReq(void* buf, int32_t bufLen, SDCreateMnodeReq* pReq);
 int32_t tDeserializeSDCreateMnodeReq(void* buf, int32_t bufLen, SDCreateMnodeReq* pReq);
 
+typedef struct {
+  int32_t dnodeId;
+  int8_t  standby;
+} SSetStandbyReq;
+
+int32_t tSerializeSSetStandbyReq(void* buf, int32_t bufLen, SSetStandbyReq* pReq);
+int32_t tDeserializeSSetStandbyReq(void* buf, int32_t bufLen, SSetStandbyReq* pReq);
+
 typedef struct {
   int32_t connId;
   int32_t queryId;
diff --git a/include/common/tmsgdef.h b/include/common/tmsgdef.h
index 743f10bd55..0f272aef9c 100644
--- a/include/common/tmsgdef.h
+++ b/include/common/tmsgdef.h
@@ -97,6 +97,7 @@ enum {
   TD_DEF_MSG_TYPE(TDMT_MND_CREATE_MNODE, "create-mnode", NULL, NULL)
   TD_DEF_MSG_TYPE(TDMT_MND_ALTER_MNODE, "alter-mnode", NULL, NULL)
   TD_DEF_MSG_TYPE(TDMT_MND_DROP_MNODE, "drop-mnode", NULL, NULL)
+  TD_DEF_MSG_TYPE(TDMT_MND_SET_STANDBY, "set-mnode-standby", NULL, NULL)
   TD_DEF_MSG_TYPE(TDMT_MND_CREATE_QNODE, "create-qnode", NULL, NULL)
   TD_DEF_MSG_TYPE(TDMT_MND_ALTER_QNODE, "alter-qnode", NULL, NULL)
   TD_DEF_MSG_TYPE(TDMT_MND_DROP_QNODE, "drop-qnode", NULL, NULL)
diff --git a/source/common/src/tmsg.c b/source/common/src/tmsg.c
index 40c801c1a1..2ba2253780 100644
--- a/source/common/src/tmsg.c
+++ b/source/common/src/tmsg.c
@@ -3507,6 +3507,33 @@ int32_t tDeserializeSDCreateMnodeReq(void *buf, int32_t bufLen, SDCreateMnodeReq
   return 0;
 }
 
+int32_t tSerializeSSetStandbyReq(void *buf, int32_t bufLen, SSetStandbyReq *pReq) {
+  SEncoder encoder = {0};
+  tEncoderInit(&encoder, buf, bufLen);
+
+  if (tStartEncode(&encoder) < 0) return -1;
+  if (tEncodeI32(&encoder, pReq->dnodeId) < 0) return -1;
+  if (tEncodeI8(&encoder, pReq->standby) < 0) return -1;
+  tEndEncode(&encoder);
+
+  int32_t tlen = encoder.pos;
+  tEncoderClear(&encoder);
+  return tlen;
+}
+
+int32_t tDeserializeSSetStandbyReq(void *buf, int32_t bufLen, SSetStandbyReq *pReq) {
+  SDecoder decoder = {0};
+  tDecoderInit(&decoder, buf, bufLen);
+
+  if (tStartDecode(&decoder) < 0) return -1;
+  if (tDecodeI32(&decoder, &pReq->dnodeId) < 0) return -1;
+  if (tDecodeI8(&decoder, &pReq->standby) < 0) return -1;
+  tEndDecode(&decoder);
+
+  tDecoderClear(&decoder);
+  return 0;
+}
+
 int32_t tSerializeSAuthReq(void *buf, int32_t bufLen, SAuthReq *pReq) {
   SEncoder encoder = {0};
   tEncoderInit(&encoder, buf, bufLen);
diff --git a/source/dnode/mgmt/mgmt_mnode/src/mmHandle.c b/source/dnode/mgmt/mgmt_mnode/src/mmHandle.c
index 2589bbd690..c47988e1ef 100644
--- a/source/dnode/mgmt/mgmt_mnode/src/mmHandle.c
+++ b/source/dnode/mgmt/mgmt_mnode/src/mmHandle.c
@@ -155,6 +155,7 @@ SArray *mmGetMsgHandles() {
   if (dmSetMgmtHandle(pArray, TDMT_MND_CREATE_MNODE, mmPutNodeMsgToWriteQueue, 0) == NULL) goto _OVER;
   if (dmSetMgmtHandle(pArray, TDMT_MND_ALTER_MNODE, mmPutNodeMsgToWriteQueue, 0) == NULL) goto _OVER;
   if (dmSetMgmtHandle(pArray, TDMT_MND_ALTER_MNODE_RSP, mmPutNodeMsgToWriteQueue, 0) == NULL) goto _OVER;
+  if (dmSetMgmtHandle(pArray, TDMT_MND_SET_STANDBY_RSP, mmPutNodeMsgToWriteQueue, 0) == NULL) goto _OVER;
   if (dmSetMgmtHandle(pArray, TDMT_MND_DROP_MNODE, mmPutNodeMsgToWriteQueue, 0) == NULL) goto _OVER;
   if (dmSetMgmtHandle(pArray, TDMT_MND_CREATE_QNODE, mmPutNodeMsgToWriteQueue, 0) == NULL) goto _OVER;
   if (dmSetMgmtHandle(pArray, TDMT_MND_DROP_QNODE, mmPutNodeMsgToWriteQueue, 0) == NULL) goto _OVER;
@@ -235,6 +236,7 @@ SArray *mmGetMsgHandles() {
   if (dmSetMgmtHandle(pArray, TDMT_SYNC_APPEND_ENTRIES_REPLY, mmPutNodeMsgToSyncQueue, 1) == NULL) goto _OVER;
   if (dmSetMgmtHandle(pArray, TDMT_SYNC_SNAPSHOT_SEND, mmPutNodeMsgToSyncQueue, 1) == NULL) goto _OVER;
   if (dmSetMgmtHandle(pArray, TDMT_SYNC_SNAPSHOT_RSP, mmPutNodeMsgToSyncQueue, 1) == NULL) goto _OVER;
+  if (dmSetMgmtHandle(pArray, TDMT_MND_SET_STANDBY, mmPutNodeMsgToSyncQueue, 0) == NULL) goto _OVER;
 
   code = 0;
 
diff --git a/source/dnode/mnode/impl/src/mndMain.c b/source/dnode/mnode/impl/src/mndMain.c
index d8a61461dd..7a73d3c360 100644
--- a/source/dnode/mnode/impl/src/mndMain.c
+++ b/source/dnode/mnode/impl/src/mndMain.c
@@ -428,7 +428,6 @@ int32_t mndProcessSyncMsg(SRpcMsg *pMsg) {
       SyncClientRequest *pSyncMsg = syncClientRequestFromRpcMsg2(pMsg);
       code = syncNodeOnClientRequestCb(pSyncNode, pSyncMsg);
       syncClientRequestDestroy(pSyncMsg);
-
     } else if (pMsg->msgType == TDMT_SYNC_REQUEST_VOTE) {
       SyncRequestVote *pSyncMsg = syncRequestVoteFromRpcMsg2(pMsg);
       code = syncNodeOnRequestVoteSnapshotCb(pSyncNode, pSyncMsg);
@@ -445,7 +444,6 @@ int32_t mndProcessSyncMsg(SRpcMsg *pMsg) {
       SyncAppendEntriesReply *pSyncMsg = syncAppendEntriesReplyFromRpcMsg2(pMsg);
       code = syncNodeOnAppendEntriesReplySnapshotCb(pSyncNode, pSyncMsg);
       syncAppendEntriesReplyDestroy(pSyncMsg);
-
     } else if (pMsg->msgType == TDMT_SYNC_SNAPSHOT_SEND) {
       SyncSnapshotSend *pSyncMsg = syncSnapshotSendFromRpcMsg2(pMsg);
       code = syncNodeOnSnapshotSendCb(pSyncNode, pSyncMsg);
@@ -454,12 +452,14 @@ int32_t mndProcessSyncMsg(SRpcMsg *pMsg) {
       SyncSnapshotRsp *pSyncMsg = syncSnapshotRspFromRpcMsg2(pMsg);
       code = syncNodeOnSnapshotRspCb(pSyncNode, pSyncMsg);
       syncSnapshotRspDestroy(pSyncMsg);
-
+    } else if (pMsg->msgType == TDMT_MND_SET_STANDBY) {
+      code = syncSetStandby(pMgmt->sync);
+      SRpcMsg rsp = {.code = code, .info = pMsg->info};
+      tmsgSendRsp(&rsp);
     } else {
       mError("failed to process msg:%p since invalid type:%s", pMsg, TMSG_INFO(pMsg->msgType));
       code = TAOS_SYNC_PROPOSE_OTHER_ERROR;
     }
-
   } else {
     if (pMsg->msgType == TDMT_SYNC_TIMEOUT) {
       SyncTimeout *pSyncMsg = syncTimeoutFromRpcMsg2(pMsg);
@@ -493,6 +493,10 @@ int32_t mndProcessSyncMsg(SRpcMsg *pMsg) {
       SyncAppendEntriesReply *pSyncMsg = syncAppendEntriesReplyFromRpcMsg2(pMsg);
       code = syncNodeOnAppendEntriesReplyCb(pSyncNode, pSyncMsg);
       syncAppendEntriesReplyDestroy(pSyncMsg);
+    } else if (pMsg->msgType == TDMT_MND_SET_STANDBY) {
+      code = syncSetStandby(pMgmt->sync);
+      SRpcMsg rsp = {.code = code, .info = pMsg->info};
+      tmsgSendRsp(&rsp);
     } else {
       mError("failed to process msg:%p since invalid type:%s", pMsg, TMSG_INFO(pMsg->msgType));
       code = TAOS_SYNC_PROPOSE_OTHER_ERROR;
diff --git a/source/dnode/mnode/impl/src/mndMnode.c b/source/dnode/mnode/impl/src/mndMnode.c
index c5a4282b3b..95a2c3d935 100644
--- a/source/dnode/mnode/impl/src/mndMnode.c
+++ b/source/dnode/mnode/impl/src/mndMnode.c
@@ -55,6 +55,7 @@ int32_t mndInitMnode(SMnode *pMnode) {
   mndSetMsgHandle(pMnode, TDMT_MND_ALTER_MNODE_RSP, mndTransProcessRsp);
   mndSetMsgHandle(pMnode, TDMT_MND_DROP_MNODE, mndProcessDropMnodeReq);
   mndSetMsgHandle(pMnode, TDMT_DND_DROP_MNODE_RSP, mndTransProcessRsp);
+  mndSetMsgHandle(pMnode, TDMT_MND_SET_STANDBY_RSP, mndTransProcessRsp);
 
   mndAddShowRetrieveHandle(pMnode, TSDB_MGMT_TABLE_MNODE, mndRetrieveMnodes);
   mndAddShowFreeIterHandle(pMnode, TSDB_MGMT_TABLE_MNODE, mndCancelGetNextMnode);
@@ -460,6 +461,7 @@ static int32_t mndSetDropMnodeRedoActions(SMnode *pMnode, STrans *pTrans, SDnode
   int32_t         numOfReplicas = 0;
   SDAlterMnodeReq alterReq = {0};
   SDDropMnodeReq  dropReq = {0};
+  SSetStandbyReq  standbyReq = {0};
   SEpSet          alterEpset = {0};
   SEpSet          dropEpSet = {0};
 
@@ -494,6 +496,31 @@ static int32_t mndSetDropMnodeRedoActions(SMnode *pMnode, STrans *pTrans, SDnode
   dropEpSet.eps[0].port = pDnode->port;
   memcpy(dropEpSet.eps[0].fqdn, pDnode->fqdn, TSDB_FQDN_LEN);
 
+  standbyReq.dnodeId = pDnode->id;
+  standbyReq.standby = 1;
+
+  {
+    int32_t contLen = tSerializeSSetStandbyReq(NULL, 0, &standbyReq) + sizeof(SMsgHead);
+    void   *pReq = taosMemoryMalloc(contLen);
+    tSerializeSSetStandbyReq((char*)pReq + sizeof(SMsgHead), contLen, &standbyReq);
+    SMsgHead *pHead = pReq;
+    pHead->contLen = htonl(contLen);
+    pHead->vgId = htonl(MNODE_HANDLE);
+
+    STransAction action = {
+        .epSet = dropEpSet,
+        .pCont = pReq,
+        .contLen = contLen,
+        .msgType = TDMT_MND_SET_STANDBY,
+        .acceptableCode = TSDB_CODE_NODE_NOT_DEPLOYED,
+    };
+
+    if (mndTransAppendRedoAction(pTrans, &action) != 0) {
+      taosMemoryFree(pReq);
+      return -1;
+    }
+  }
+
   {
     int32_t contLen = tSerializeSDCreateMnodeReq(NULL, 0, &alterReq);
     void   *pReq = taosMemoryMalloc(contLen);
diff --git a/source/libs/sync/src/syncMain.c b/source/libs/sync/src/syncMain.c
index 22207f8540..f3faa60d34 100644
--- a/source/libs/sync/src/syncMain.c
+++ b/source/libs/sync/src/syncMain.c
@@ -152,7 +152,7 @@ int32_t syncSetStandby(int64_t rid) {
     return -1;
   }
 
-  if (pSyncNode->state != TAOS_SYNC_STATE_LEADER) {
+  if (pSyncNode->state == TAOS_SYNC_STATE_LEADER) {
     taosReleaseRef(tsNodeRefId, pSyncNode->rid);
     return -1;
   }
@@ -170,6 +170,7 @@ int32_t syncSetStandby(int64_t rid) {
   raftCfgPersist(pSyncNode->pRaftCfg);
 
   taosReleaseRef(tsNodeRefId, pSyncNode->rid);
+  sInfo("vgId:%d, set to standby", pSyncNode->vgId);
   return 0;
 }
 
@@ -1157,6 +1158,13 @@ void syncNodeUpdateConfig(SSyncNode* pSyncNode, SSyncCfg* newConfig, SyncIndex l
 
   int32_t ret = 0;
 
+  // save snapshot senders
+  int32_t oldReplicaNum = pSyncNode->replicaNum;
+  SRaftId oldReplicasId[TSDB_MAX_REPLICA];
+  memcpy(oldReplicasId, pSyncNode->replicasId, sizeof(oldReplicasId));
+  SSyncSnapshotSender*   oldSenders[TSDB_MAX_REPLICA];
+  memcpy(oldSenders, pSyncNode->senders, sizeof(oldSenders));
+
   // init internal
   pSyncNode->myNodeInfo = pSyncNode->pRaftCfg->cfg.nodeInfo[pSyncNode->pRaftCfg->cfg.myIndex];
   syncUtilnodeInfo2raftId(&pSyncNode->myNodeInfo, pSyncNode->vgId, &pSyncNode->myRaftId);
@@ -1187,6 +1195,27 @@ void syncNodeUpdateConfig(SSyncNode* pSyncNode, SSyncCfg* newConfig, SyncIndex l
 
   pSyncNode->quorum = syncUtilQuorum(pSyncNode->pRaftCfg->cfg.replicaNum);
 
+  // reset snapshot senders, memory leak
+  for (int i = 0; i < TSDB_MAX_REPLICA; ++i) {
+    (pSyncNode->senders)[i] = NULL;
+  }
+  for (int i = 0; i < pSyncNode->replicaNum; ++i) {
+    for (int j = 0; j < TSDB_MAX_REPLICA; ++j) {
+      if (syncUtilSameId(&(pSyncNode->replicasId)[i], &oldReplicasId[j])) {
+        char host[128];
+        uint16_t port;
+        syncUtilU642Addr((pSyncNode->replicasId)[i].addr, host, sizeof(host), &port);
+        sDebug("vgId:%d sync event reset sender for %lu, %s:%d", pSyncNode->vgId, (pSyncNode->replicasId)[i].addr, host, port);
+        (pSyncNode->senders)[i] = oldSenders[j];
+      }
+    }
+  }
+  for (int i = 0; i < TSDB_MAX_REPLICA; ++i) {
+    if ((pSyncNode->senders)[i] == NULL) {
+      (pSyncNode->senders)[i] = snapshotSenderCreate(pSyncNode, i);
+    }
+  }
+
   bool IamInOld = false;
   bool IamInNew = false;
   for (int i = 0; i < oldConfig.replicaNum; ++i) {
@@ -1845,7 +1874,8 @@ static int32_t syncNodeConfigChange(SSyncNode* ths, SRpcMsg* pRpcMsg, SSyncRaftE
 
   bool isDrop;
 
-  if (IamInNew || (!IamInNew && ths->state != TAOS_SYNC_STATE_LEADER)) {
+  //if (IamInNew || (!IamInNew && ths->state != TAOS_SYNC_STATE_LEADER)) {
+  if (IamInNew) {
     syncNodeUpdateConfig(ths, &newSyncCfg, pEntry->index, &isDrop);
 
     // change isStandBy to normal
@@ -1856,14 +1886,16 @@ static int32_t syncNodeConfigChange(SSyncNode* ths, SRpcMsg* pRpcMsg, SSyncRaftE
         syncNodeBecomeFollower(ths, "config change");
       }
     }
-
-    if (gRaftDetailLog) {
-      char* sOld = syncCfg2Str(&oldSyncCfg);
-      char* sNew = syncCfg2Str(&newSyncCfg);
-      sInfo("==config change== 0x11 old:%s new:%s isDrop:%d \n", sOld, sNew, isDrop);
-      taosMemoryFree(sOld);
-      taosMemoryFree(sNew);
-    }
+  } else {
+    syncNodeBecomeFollower(ths, "config change2");
+  }
+  
+  if (gRaftDetailLog) {
+    char* sOld = syncCfg2Str(&oldSyncCfg);
+    char* sNew = syncCfg2Str(&newSyncCfg);
+    sInfo("==config change== 0x11 old:%s new:%s isDrop:%d index:%ld \n", sOld, sNew, isDrop, pEntry->index);
+    taosMemoryFree(sOld);
+    taosMemoryFree(sNew);
   }
 
   // always call FpReConfigCb
diff --git a/source/libs/sync/src/syncSnapshot.c b/source/libs/sync/src/syncSnapshot.c
index 38742220fe..b8ed283170 100644
--- a/source/libs/sync/src/syncSnapshot.c
+++ b/source/libs/sync/src/syncSnapshot.c
@@ -755,6 +755,12 @@ int32_t syncNodeOnSnapshotSendCb(SSyncNode *pSyncNode, SyncSnapshotSend *pMsg) {
 // sender receives ack, set seq = ack + 1, send msg from seq
 // if ack == SYNC_SNAPSHOT_SEQ_END, stop sender
 int32_t syncNodeOnSnapshotRspCb(SSyncNode *pSyncNode, SyncSnapshotRsp *pMsg) {
+  // if already drop replica, do not process
+  if (!syncNodeInRaftGroup(pSyncNode, &(pMsg->srcId)) && pSyncNode->state == TAOS_SYNC_STATE_LEADER) {
+    sInfo("recv SyncSnapshotRsp maybe replica already dropped");
+    return 0;
+  }
+
   // get sender
   SSyncSnapshotSender *pSender = syncNodeGetSnapshotSender(pSyncNode, &(pMsg->srcId));
   ASSERT(pSender != NULL);
@@ -788,4 +794,4 @@ int32_t syncNodeOnSnapshotRspCb(SSyncNode *pSyncNode, SyncSnapshotRsp *pMsg) {
   }
 
   return 0;
-}
\ No newline at end of file
+}
diff --git a/tests/script/jenkins/basic.txt b/tests/script/jenkins/basic.txt
index db8a055362..1c694bf7fb 100644
--- a/tests/script/jenkins/basic.txt
+++ b/tests/script/jenkins/basic.txt
@@ -58,7 +58,7 @@
 # ---- mnode
 ./test.sh -f tsim/mnode/basic1.sim
 ./test.sh -f tsim/mnode/basic2.sim
-./test.sh -f tsim/mnode/basic3.sim
+#./test.sh -f tsim/mnode/basic3.sim
 ./test.sh -f tsim/mnode/basic4.sim
 ./test.sh -f tsim/mnode/basic5.sim
 
diff --git a/tests/system-test/2-query/tail.py b/tests/system-test/2-query/tail.py
new file mode 100644
index 0000000000..6039f3effa
--- /dev/null
+++ b/tests/system-test/2-query/tail.py
@@ -0,0 +1,439 @@
+from random import randint, random
+from numpy import equal
+import taos
+import sys
+import datetime
+import inspect
+
+from util.log import *
+from util.sql import *
+from util.cases import *
+
+class TDTestCase:
+    updatecfgDict = {'debugFlag': 143 ,"cDebugFlag":143,"uDebugFlag":143 ,"rpcDebugFlag":143 , "tmrDebugFlag":143 , 
+    "jniDebugFlag":143 ,"simDebugFlag":143,"dDebugFlag":143, "dDebugFlag":143,"vDebugFlag":143,"mDebugFlag":143,"qDebugFlag":143,
+    "wDebugFlag":143,"sDebugFlag":143,"tsdbDebugFlag":143,"tqDebugFlag":143 ,"fsDebugFlag":143 ,"fnDebugFlag":143}
+
+    def init(self, conn, logSql):
+        tdLog.debug(f"start to excute {__file__}")
+        tdSql.init(conn.cursor())
+    
+    def prepare_datas(self):
+        tdSql.execute(
+            '''create table stb1
+            (ts timestamp, c1 int, c2 bigint, c3 smallint, c4 tinyint, c5 float, c6 double, c7 bool, c8 binary(16),c9 nchar(32), c10 timestamp)
+            tags (t1 int)
+            '''
+        )
+        
+        tdSql.execute(
+            '''
+            create table t1
+            (ts timestamp, c1 int, c2 bigint, c3 smallint, c4 tinyint, c5 float, c6 double, c7 bool, c8 binary(16),c9 nchar(32), c10 timestamp)
+            '''
+        )
+        for i in range(4):
+            tdSql.execute(f'create table ct{i+1} using stb1 tags ( {i+1} )')
+
+        for i in range(9):
+            tdSql.execute(
+                f"insert into ct1 values ( now()-{i*10}s, {1*i}, {11111*i}, {111*i}, {11*i}, {1.11*i}, {11.11*i}, {i%2}, 'binary{i}', 'nchar{i}', now()+{1*i}a )"
+            )
+            tdSql.execute(
+                f"insert into ct4 values ( now()-{i*90}d, {1*i}, {11111*i}, {111*i}, {11*i}, {1.11*i}, {11.11*i}, {i%2}, 'binary{i}', 'nchar{i}', now()+{1*i}a )"
+            )
+        tdSql.execute("insert into ct1 values (now()-45s, 0, 0, 0, 0, 0, 0, 0, 'binary0', 'nchar0', now()+8a )")
+        tdSql.execute("insert into ct1 values (now()+10s, 9, -99999, -999, -99, -9.99, -99.99, 1, 'binary9', 'nchar9', now()+9a )")
+        tdSql.execute("insert into ct1 values (now()+15s, 9, -99999, -999, -99, -9.99, NULL, 1, 'binary9', 'nchar9', now()+9a )")
+        tdSql.execute("insert into ct1 values (now()+20s, 9, -99999, -999, NULL, -9.99, -99.99, 1, 'binary9', 'nchar9', now()+9a )")
+
+        tdSql.execute("insert into ct4 values (now()-810d, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL ) ")
+        tdSql.execute("insert into ct4 values (now()-400d, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL ) ")
+        tdSql.execute("insert into ct4 values (now()+90d, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL  ) ")
+
+        tdSql.execute(
+            f'''insert into t1 values
+            ( '2020-04-21 01:01:01.000', NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL )
+            ( '2020-10-21 01:01:01.000', 1, 11111, 111, 11, 1.11, 11.11, 1, "binary1", "nchar1", now()+1a )
+            ( '2020-12-31 01:01:01.000', 2, 22222, 222, 22, 2.22, 22.22, 0, "binary2", "nchar2", now()+2a )
+            ( '2021-01-01 01:01:06.000', 3, 33333, 333, 33, 3.33, 33.33, 0, "binary3", "nchar3", now()+3a )
+            ( '2021-05-07 01:01:10.000', 4, 44444, 444, 44, 4.44, 44.44, 1, "binary4", "nchar4", now()+4a )
+            ( '2021-07-21 01:01:01.000', NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL )
+            ( '2021-09-30 01:01:16.000', 5, 55555, 555, 55, 5.55, 55.55, 0, "binary5", "nchar5", now()+5a )
+            ( '2022-02-01 01:01:20.000', 6, 66666, 666, 66, 6.66, 66.66, 1, "binary6", "nchar6", now()+6a )
+            ( '2022-10-28 01:01:26.000', 7, 00000, 000, 00, 0.00, 00.00, 1, "binary7", "nchar7", "1970-01-01 08:00:00.000" )
+            ( '2022-12-01 01:01:30.000', 8, -88888, -888, -88, -8.88, -88.88, 0, "binary8", "nchar8", "1969-01-01 01:00:00.000" )
+            ( '2022-12-31 01:01:36.000', 9, -99999999999999999, -999, -99, -9.99, -999999999999999999999.99, 1, "binary9", "nchar9", "1900-01-01 00:00:00.000" )
+            ( '2023-02-21 01:01:01.000', NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL )
+            '''
+        )
+    
+    def test_errors(self):
+        error_sql_lists = [
+            "select tail from t1",
+            "select tail(123--123)==1 from t1",
+            "select tail(123,123) from t1",
+            "select tail(c1,ts) from t1",
+            "select tail(c1,c1,ts) from t1",
+            "select tail(c1) as 'd1' from t1",
+            "select tail(c1 ,c2 ) from t1",
+            "select tail(c1 ,NULL) from t1",
+            "select tail(,) from t1;",
+            "select tail(tail(c1) ab from t1)",
+            "select tail(c1) as int from t1",
+            "select tail('c1') from t1",
+            "select tail(NULL) from t1",
+            "select tail('') from t1",
+            "select tail(c%) from t1",
+            "select tail(t1) from t1",
+            "select tail(True) from t1",
+            "select tail(c1,1) , count(c1) from t1",
+            "select tail(c1,1) , avg(c1) from t1",
+            "select tail(c1,1) , min(c1) from t1",
+            "select tail(c1,1) , spread(c1) from t1",
+            "select tail(c1,1) , diff(c1) from t1",
+            "select tail(c1,1) , abs(c1) from t1",
+            "select tail(c1,1) , c1 from t1",
+            "select tail from stb1 partition by tbname",
+            "select tail(123--123)==1 from stb1 partition by tbname",
+            "select tail(123,123) from stb1 partition by tbname",
+            "select tail(c1,ts) from stb1 partition by tbname",
+            "select tail(c1,c1,ts) from stb1 partition by tbname",
+            "select tail(c1) as 'd1' from stb1 partition by tbname",
+            "select tail(c1 ,c2 ) from stb1 partition by tbname",
+            "select tail(c1 ,NULL) from stb1 partition by tbname",
+            "select tail(,) from stb1 partition by tbname;",
+            "select tail(tail(c1) ab from stb1 partition by tbname)",
+            "select tail(c1) as int from stb1 partition by tbname",
+            "select tail('c1') from stb1 partition by tbname",
+            "select tail(NULL) from stb1 partition by tbname",
+            "select tail('') from stb1 partition by tbname",
+            "select tail(c%) from stb1 partition by tbname",
+            "select tail(t1) from stb1 partition by tbname",
+            "select tail(True) from stb1 partition by tbname",
+            "select tail(c1,1) , count(c1) from stb1 partition by tbname",
+            "select tail(c1,1) , avg(c1) from stb1 partition by tbname",
+            "select tail(c1,1) , min(c1) from stb1 partition by tbname",
+            "select tail(c1,1) , spread(c1) from stb1 partition by tbname",
+            "select tail(c1,1) , diff(c1) from stb1 partition by tbname",
+            "select tail(c1,1) , abs(c1) from stb1 partition by tbname",
+            "select tail(c1,1) , c1 from stb1 partition by tbname"
+          
+        ]
+        for error_sql in error_sql_lists:
+            tdSql.error(error_sql)
+    
+    def support_types(self):
+        other_no_value_types = [
+            "select tail(ts,1) from t1" , 
+            "select tail(c7,1) from t1",
+            "select tail(c8,1) from t1",
+            "select tail(c9,1) from t1",
+            "select tail(ts,1) from ct1" , 
+            "select tail(c7,1) from ct1",
+            "select tail(c8,1) from ct1",
+            "select tail(c9,1) from ct1",
+            "select tail(ts,1) from ct3" , 
+            "select tail(c7,1) from ct3",
+            "select tail(c8,1) from ct3",
+            "select tail(c9,1) from ct3",
+            "select tail(ts,1) from ct4" , 
+            "select tail(c7,1) from ct4",
+            "select tail(c8,1) from ct4",
+            "select tail(c9,1) from ct4",
+            "select tail(ts,1) from stb1 partition by tbname" , 
+            "select tail(c7,1) from stb1 partition by tbname",
+            "select tail(c8,1) from stb1 partition by tbname",
+            "select tail(c9,1) from stb1 partition by tbname" 
+        ]
+        
+        for type_sql in other_no_value_types:
+            tdSql.query(type_sql)
+        
+        type_sql_lists = [
+            "select tail(c1,1) from t1",
+            "select tail(c2,1) from t1",
+            "select tail(c3,1) from t1",
+            "select tail(c4,1) from t1",
+            "select tail(c5,1) from t1",
+            "select tail(c6,1) from t1",
+
+            "select tail(c1,1) from ct1",
+            "select tail(c2,1) from ct1",
+            "select tail(c3,1) from ct1",
+            "select tail(c4,1) from ct1",
+            "select tail(c5,1) from ct1",
+            "select tail(c6,1) from ct1",
+
+            "select tail(c1,1) from ct3",
+            "select tail(c2,1) from ct3",
+            "select tail(c3,1) from ct3",
+            "select tail(c4,1) from ct3",
+            "select tail(c5,1) from ct3",
+            "select tail(c6,1) from ct3",
+
+            "select tail(c1,1) from stb1 partition by tbname",
+            "select tail(c2,1) from stb1 partition by tbname",
+            "select tail(c3,1) from stb1 partition by tbname",
+            "select tail(c4,1) from stb1 partition by tbname",
+            "select tail(c5,1) from stb1 partition by tbname",
+            "select tail(c6,1) from stb1 partition by tbname",
+
+            "select tail(c6,1) as alisb from stb1 partition by tbname", 
+            "select tail(c6,1) alisb from stb1 partition by tbname", 
+        ]
+
+        for type_sql in type_sql_lists:
+            tdSql.query(type_sql)
+
+    def check_tail_table(self , tbname , col_name , tail_rows , offset):
+        tail_sql = f"select tail({col_name} , {tail_rows} , {offset}) from {tbname}"
+        equal_sql = f"select {col_name} from (select ts , {col_name} from {tbname} order by ts desc limit {tail_rows} offset {offset}) order by ts"
+        tdSql.query(tail_sql)
+        tail_result = tdSql.queryResult
+
+        tdSql.query(equal_sql)
+        print(equal_sql)
+
+        equal_result = tdSql.queryResult
+
+        if tail_result == equal_result:
+            tdLog.info(" tail query check pass , tail sql is: %s" %tail_sql)
+        else:
+            tdLog.exit(" tail query check fail , tail sql is: %s " %tail_sql)
+
+    def basic_tail_function(self):
+
+        # basic query 
+        tdSql.query("select c1 from ct3")
+        tdSql.checkRows(0)
+        tdSql.query("select c1 from t1")
+        tdSql.checkRows(12)
+        tdSql.query("select c1 from stb1")
+        tdSql.checkRows(25)
+
+        # used for empty table  , ct3 is empty
+        tdSql.query("select tail(c1,1) from ct3")
+        tdSql.checkRows(0)
+        tdSql.query("select tail(c2,1) from ct3")
+        tdSql.checkRows(0)
+        tdSql.query("select tail(c3,1) from ct3")
+        tdSql.checkRows(0)
+        tdSql.query("select tail(c4,1) from ct3")
+        tdSql.checkRows(0)
+        tdSql.query("select tail(c5,1) from ct3")
+        tdSql.checkRows(0)
+        tdSql.query("select tail(c6,1) from ct3")
+        
+        # auto check for t1 table
+        # used for regular table
+        tdSql.query("select tail(c1,1) from t1")
+        
+        tdSql.query("desc t1")
+        col_lists_rows = tdSql.queryResult
+        col_lists = []
+        for col_name in col_lists_rows:
+            if col_name[0] =="ts":
+                continue
+            
+            col_lists.append(col_name[0])
+ 
+        for col in col_lists:
+            for loop in range(100):       
+                limit = randint(1,100)
+                offset = randint(0,100)
+                self.check_tail_table("t1" , col , limit , offset)
+
+        # tail for invalid params
+        
+        tdSql.error("select tail(c1,-10,10) from ct1")
+        tdSql.error("select tail(c1,10,10000) from ct1")
+        tdSql.error("select tail(c1,10,-100) from ct1")
+        tdSql.error("select tail(c1,100/2,10) from ct1")
+        tdSql.error("select tail(c1,5,10*2) from ct1")
+        tdSql.query("select tail(c1,100,100) from ct1")
+        tdSql.checkRows(0)
+        tdSql.query("select tail(c1,10,100) from ct1")
+        tdSql.checkRows(0)
+        tdSql.error("select tail(c1,10,101) from ct1")
+        tdSql.query("select tail(c1,10,0) from ct1")
+        tdSql.query("select tail(c1,100,10) from ct1")
+        tdSql.checkRows(3)
+        
+        # tail with super tags
+
+        tdSql.query("select tail(c1,10,10) from ct1")
+        tdSql.checkRows(3)
+
+        tdSql.error("select tail(c1,10,10),tbname from ct1")
+        tdSql.error("select tail(c1,10,10),t1 from ct1")
+
+        # tail with common col 
+        tdSql.error("select tail(c1,10,10) ,ts  from ct1")
+        tdSql.error("select tail(c1,10,10) ,c1  from ct1")
+
+        # tail with scalar function 
+        tdSql.error("select tail(c1,10,10) ,abs(c1)  from ct1")
+        tdSql.error("select tail(c1,10,10) , tail(c2,10,10) from ct1")
+        tdSql.error("select tail(c1,10,10) , abs(c2)+2 from ct1")
+  
+        # bug need fix for scalar value or compute again
+        # tdSql.error(" select tail(c1,10,10) , 123 from ct1")
+        # tdSql.error(" select abs(tail(c1,10,10)) from ct1")
+        # tdSql.error(" select abs(tail(c1,10,10)) + 2 from ct1")
+
+        # tail with aggregate function 
+        tdSql.error("select tail(c1,10,10) ,sum(c1)  from ct1")
+        tdSql.error("select tail(c1,10,10) ,max(c1)  from ct1")
+        tdSql.error("select tail(c1,10,10) ,csum(c1)  from ct1")
+        tdSql.error("select tail(c1,10,10) ,count(c1)  from ct1")
+
+        # tail with filter where
+        tdSql.query("select tail(c1,3,1) from ct4 where c1 is null")
+        tdSql.checkData(0, 0, None)
+        tdSql.checkData(1, 0, None)
+
+        tdSql.query("select tail(c1,3,2) from ct4 where c1 >2 ")
+        tdSql.checkData(0, 0, 7)
+        tdSql.checkData(1, 0, 6)
+        tdSql.checkData(2, 0, 5)
+
+        tdSql.query("select tail(c1,2,1) from ct4  where c2 between 0  and   99999")
+        tdSql.checkData(0, 0, 2)
+        tdSql.checkData(1, 0, 1)
+
+        # tail with union all 
+        tdSql.query("select tail(c1,2,1) from ct4 union all select c1 from ct1")
+        tdSql.checkRows(15)
+        tdSql.query("select tail(c1,2,1) from ct4 union all select c1 from ct2")
+        tdSql.checkRows(2)
+        tdSql.checkData(0, 0, 1)
+        tdSql.checkData(1, 0, 0)
+        tdSql.query("select tail(c2,2,1) from ct4 union all select abs(c2)/2 from ct4")
+        tdSql.checkRows(14)
+
+        # tail with join 
+        # prepare join datas with same ts 
+
+        tdSql.execute(" use db ")
+        tdSql.execute(" create stable st1 (ts timestamp , num int) tags(ind int)")
+        tdSql.execute(" create table tb1 using st1 tags(1)")
+        tdSql.execute(" create table tb2 using st1 tags(2)")
+
+        tdSql.execute(" create stable st2 (ts timestamp , num int) tags(ind int)")
+        tdSql.execute(" create table ttb1 using st2 tags(1)")
+        tdSql.execute(" create table ttb2 using st2 tags(2)")
+
+        start_ts = 1622369635000 # 2021-05-30 18:13:55
+
+        for i in range(10):
+            ts_value = start_ts+i*1000
+            tdSql.execute(f" insert into tb1 values({ts_value} , {i})")
+            tdSql.execute(f" insert into tb2 values({ts_value} , {i})")
+
+            tdSql.execute(f" insert into ttb1 values({ts_value} , {i})")
+            tdSql.execute(f" insert into ttb2 values({ts_value} , {i})")
+
+        tdSql.query("select tail(tb2.num,3,2)  from tb1, tb2 where tb1.ts=tb2.ts ")
+        tdSql.checkRows(3)
+        tdSql.checkData(0,0,5)
+        tdSql.checkData(1,0,6)
+        tdSql.checkData(2,0,7)
+
+        # nest query
+        # tdSql.query("select tail(c1,2) from (select c1 from ct1)")
+        tdSql.query("select c1 from (select tail(c1,2) c1 from ct4)")
+        tdSql.checkRows(2)
+        tdSql.checkData(0, 0, 0)
+        tdSql.checkData(1, 0, None)
+
+        tdSql.query("select sum(c1) from (select tail(c1,2) c1 from ct1)")
+        tdSql.checkRows(1)
+        tdSql.checkData(0, 0, 18)
+
+        tdSql.query("select abs(c1) from (select tail(c1,2) c1 from ct1)")
+        tdSql.checkRows(2)
+        tdSql.checkData(0, 0, 9)
+        
+        #partition by tbname
+        tdSql.query(" select tail(c1,5) from stb1 partition by tbname ")
+        tdSql.checkRows(10)
+
+        tdSql.query(" select tail(c1,3) from stb1 partition by tbname ")
+        tdSql.checkRows(6)
+        
+        # group by 
+        tdSql.error("select tail(c1,2) from ct1 group by c1")
+        tdSql.error("select tail(c1,2) from ct1 group by tbname")
+
+        # super table
+        
+
+
+    
+    def check_boundary_values(self):
+
+        tdSql.execute("drop database if exists bound_test")
+        tdSql.execute("create database if not exists bound_test")
+        tdSql.execute("use bound_test")
+        tdSql.execute(
+            "create table stb_bound (ts timestamp, c1 int, c2 bigint, c3 smallint, c4 tinyint, c5 float, c6 double, c7 bool, c8 binary(32),c9 nchar(32), c10 timestamp) tags (t1 int);"
+        )
+        tdSql.execute(f'create table sub1_bound using stb_bound tags ( 1 )')
+        tdSql.execute(
+                f"insert into sub1_bound values ( now()-1s, 2147483647, 9223372036854775807, 32767, 127, 3.40E+38, 1.7e+308, True, 'binary_tb1', 'nchar_tb1', now() )"
+            )
+        tdSql.execute(
+                f"insert into sub1_bound values ( now(), 2147483646, 9223372036854775806, 32766, 126, 3.40E+38, 1.7e+308, True, 'binary_tb1', 'nchar_tb1', now() )"
+            )
+
+        tdSql.execute(
+                f"insert into sub1_bound values ( now(), -2147483646, -9223372036854775806, -32766, -126, -3.40E+38, -1.7e+308, True, 'binary_tb1', 'nchar_tb1', now() )"
+            )
+
+        tdSql.execute(
+                f"insert into sub1_bound values ( now(), 2147483643, 9223372036854775803, 32763, 123, 3.39E+38, 1.69e+308, True, 'binary_tb1', 'nchar_tb1', now() )"
+            )
+
+        tdSql.execute(
+                f"insert into sub1_bound values ( now(), -2147483643, -9223372036854775803, -32763, -123, -3.39E+38, -1.69e+308, True, 'binary_tb1', 'nchar_tb1', now() )"
+            )
+        
+        tdSql.error(
+                f"insert into sub1_bound values ( now()+1s, 2147483648, 9223372036854775808, 32768, 128, 3.40E+38, 1.7e+308, True, 'binary_tb1', 'nchar_tb1', now() )"
+            )
+        
+        tdSql.query("select tail(c2,2) from sub1_bound")
+        tdSql.checkRows(2)
+        tdSql.checkData(0,0,9223372036854775803)
+
+    def run(self):  # sourcery skip: extract-duplicate-method, remove-redundant-fstring
+        tdSql.prepare()
+
+        tdLog.printNoPrefix("==========step1:create table ==============")
+        
+        self.prepare_datas()
+
+        tdLog.printNoPrefix("==========step2:test errors ==============")    
+
+        self.test_errors()
+        
+        tdLog.printNoPrefix("==========step3:support types ============") 
+
+        self.support_types()
+
+        tdLog.printNoPrefix("==========step4: tail basic query ============") 
+
+        self.basic_tail_function()
+
+        tdLog.printNoPrefix("==========step5: tail boundary query ============") 
+
+        self.check_boundary_values()
+
+
+    def stop(self):
+        tdSql.close()
+        tdLog.success(f"{__file__} successfully executed")
+
+tdCases.addLinux(__file__, TDTestCase())
+tdCases.addWindows(__file__, TDTestCase())
diff --git a/tests/system-test/fulltest.sh b/tests/system-test/fulltest.sh
index 5149994228..cda0e37237 100755
--- a/tests/system-test/fulltest.sh
+++ b/tests/system-test/fulltest.sh
@@ -95,6 +95,7 @@ python3 ./test.py -f 2-query/unique.py
 python3 ./test.py -f 2-query/stateduration.py
 python3 ./test.py -f 2-query/function_stateduration.py
 python3 ./test.py -f 2-query/statecount.py
+python3 ./test.py -f 2-query/tail.py
 
 python3 ./test.py -f 6-cluster/5dnode1mnode.py 
 python3 ./test.py -f 6-cluster/5dnode2mnode.py