diff --git a/src/sync/src/syncMain.c b/src/sync/src/syncMain.c
index ef635e6efc1ca5f071c64dbe00920c3987837494..6f5e3be8ab4965331f23d2e2b7307823981205a5 100644
--- a/src/sync/src/syncMain.c
+++ b/src/sync/src/syncMain.c
@@ -20,6 +20,7 @@
 #include "tlog.h"
 #include "tutil.h"
 #include "ttimer.h"
+#include "tref.h"
 #include "tsocket.h"
 #include "tglobal.h"
 #include "taoserror.h"
@@ -43,6 +44,7 @@ char tsNodeFqdn[TSDB_FQDN_LEN];
 static ttpool_h tsTcpPool;
 static void *   syncTmrCtrl = NULL;
 static void *   vgIdHash;
+static int      tsSyncRefId = -1;
 
 // local functions
 static void  syncProcessSyncRequest(char *pMsg, SSyncPeer *pPeer);
@@ -54,13 +56,13 @@ static int   syncProcessPeerMsg(void *param, void *buffer);
 static void  syncProcessIncommingConnection(int connFd, uint32_t sourceIp); 
 static void  syncRemovePeer(SSyncPeer *pPeer);
 static void  syncAddArbitrator(SSyncNode *pNode);
-static void  syncAddNodeRef(SSyncNode *pNode);
-static void  syncDecNodeRef(SSyncNode *pNode);
+static void  syncFreeNode(void *);
 static void  syncRemoveConfirmedFwdInfo(SSyncNode *pNode);
 static void  syncMonitorFwdInfos(void *param, void *tmrId);
 static void  syncProcessFwdAck(SSyncNode *pNode, SFwdInfo *pFwdInfo, int32_t code);
 static void  syncSaveFwdInfo(SSyncNode *pNode, uint64_t version, void *mhandle); 
 static void  syncRestartPeer(SSyncPeer *pPeer);
+static int32_t syncForwardToPeerImpl(SSyncNode *pNode, void *data, void *mhandle, int qtyp);
 static SSyncPeer *syncAddPeer(SSyncNode *pNode, const SNodeInfo *pInfo);
 
 char* syncRole[] = {
@@ -106,6 +108,12 @@ int32_t syncInit() {
     return -1;
   }
 
+  tsSyncRefId = taosOpenRef(200, syncFreeNode);
+  if (tsSyncRefId < 0) {
+    syncCleanUp();
+    return -1;
+  }
+
   tstrncpy(tsNodeFqdn, tsLocalFqdn, sizeof(tsNodeFqdn));
   sInfo("sync module initialized successfully");
 
@@ -128,6 +136,9 @@ void syncCleanUp() {
     vgIdHash = NULL;
   }
 
+  taosCloseRef(tsSyncRefId);
+  tsSyncRefId = -1;
+
   sInfo("sync module is cleaned up");
 }
 
@@ -159,6 +170,12 @@ void *syncStart(const SSyncInfo *pInfo) {
   pNode->quorum = pCfg->quorum;
   if (pNode->quorum > pNode->replica) pNode->quorum = pNode->replica;
 
+  int ret = taosAddRef(tsSyncRefId, pNode);
+  if (ret < 0) {
+    syncFreeNode(pNode);
+    return NULL;
+  }
+
   for (int i = 0; i < pCfg->replica; ++i) {
     const SNodeInfo *pNodeInfo = pCfg->nodeInfo + i;
     pNode->peerInfo[i] = syncAddPeer(pNode, pNodeInfo);
@@ -167,8 +184,6 @@ void *syncStart(const SSyncInfo *pInfo) {
     }
   }
 
-  syncAddNodeRef(pNode);
-
   if (pNode->selfIndex < 0) {
     sInfo("vgId:%d, this node is not configured", pNode->vgId);
     terrno = TSDB_CODE_SYN_INVALID_CONFIG;
@@ -210,7 +225,9 @@ void syncStop(void *param) {
   SSyncNode *pNode = param;
   SSyncPeer *pPeer;
 
-  if (pNode == NULL) return;
+  int ret = taosAcquireRef(tsSyncRefId, pNode);
+  if (ret < 0) return;
+
   sInfo("vgId:%d, cleanup sync", pNode->vgId);
 
   pthread_mutex_lock(&(pNode->mutex));
@@ -228,14 +245,17 @@ void syncStop(void *param) {
 
   pthread_mutex_unlock(&(pNode->mutex));
 
-  syncDecNodeRef(pNode);
+  taosReleaseRef(tsSyncRefId, pNode);
+  taosRemoveRef(tsSyncRefId, pNode);
 }
 
 int32_t syncReconfig(void *param, const SSyncCfg *pNewCfg) {
   SSyncNode *pNode = param;
   int        i, j;
 
-  if (pNode == NULL) return TSDB_CODE_SYN_INVALID_CONFIG;
+  int ret = taosAcquireRef(tsSyncRefId, pNode);
+  if (ret < 0) return TSDB_CODE_SYN_INVALID_CONFIG;
+
   sInfo("vgId:%d, reconfig, role:%s replica:%d old:%d", pNode->vgId, syncRole[nodeRole], pNewCfg->replica,
         pNode->replica);
 
@@ -298,105 +318,63 @@ int32_t syncReconfig(void *param, const SSyncCfg *pNewCfg) {
         syncRole[nodeRole]);
   syncBroadcastStatus(pNode);
 
+  taosReleaseRef(tsSyncRefId, pNode);
+
   return 0;
 }
 
 int32_t syncForwardToPeer(void *param, void *data, void *mhandle, int qtype) {
   SSyncNode *pNode = param;
-  SSyncPeer *pPeer;
-  SSyncHead *pSyncHead;
-  SWalHead * pWalHead = data;
-  int        fwdLen;
-  int        code = 0;
-
-  if (pNode == NULL) return 0;
-
-  if (nodeRole == TAOS_SYNC_ROLE_SLAVE && pWalHead->version != nodeVersion + 1) {
-    sError("vgId:%d, received ver:%" PRIu64 ", inconsistent with last ver:%" PRIu64 ", restart connection", pNode->vgId,
-           pWalHead->version, nodeVersion);
-    for (int i = 0; i < pNode->replica; ++i) {
-      pPeer = pNode->peerInfo[i];
-      syncRestartConnection(pPeer);
-    }
-    return TSDB_CODE_SYN_INVALID_VERSION;
-  }
-
-  // always update version
-  nodeVersion = pWalHead->version;
-  sDebug("vgId:%d, replica:%d nodeRole:%s qtype:%d ver:%" PRIu64, pNode->vgId, pNode->replica, syncRole[nodeRole],
-         qtype, pWalHead->version);
-
-  if (pNode->replica == 1 || nodeRole != TAOS_SYNC_ROLE_MASTER) return 0;
-
-  // only pkt from RPC or CQ can be forwarded
-  if (qtype != TAOS_QTYPE_RPC && qtype != TAOS_QTYPE_CQ) return 0;
 
-  // a hacker way to improve the performance
-  pSyncHead = (SSyncHead *)(((char *)pWalHead) - sizeof(SSyncHead));
-  pSyncHead->type = TAOS_SMSG_FORWARD;
-  pSyncHead->pversion = 0;
-  pSyncHead->len = sizeof(SWalHead) + pWalHead->len;
-  fwdLen = pSyncHead->len + sizeof(SSyncHead);  // include the WAL and SYNC head
+  int ret = taosAcquireRef(tsSyncRefId, pNode);
+  if (ret < 0) return 0; 
 
-  pthread_mutex_lock(&(pNode->mutex));
+  int32_t code = syncForwardToPeerImpl(pNode, data, mhandle, qtype);
 
-  for (int i = 0; i < pNode->replica; ++i) {
-    pPeer = pNode->peerInfo[i];
-    if (pPeer == NULL || pPeer->peerFd < 0) continue;
-    if (pPeer->role != TAOS_SYNC_ROLE_SLAVE && pPeer->sstatus != TAOS_SYNC_STATUS_CACHE) continue;
-
-    if (pNode->quorum > 1 && code == 0) {
-      syncSaveFwdInfo(pNode, pWalHead->version, mhandle);
-      code = 1;
-    }
-
-    int retLen = write(pPeer->peerFd, pSyncHead, fwdLen);
-    if (retLen == fwdLen) {
-      sDebug("%s, forward is sent, ver:%" PRIu64 " contLen:%d", pPeer->id, pWalHead->version, pWalHead->len);
-    } else {
-      sError("%s, failed to forward, ver:%" PRIu64 " retLen:%d", pPeer->id, pWalHead->version, retLen);
-      syncRestartConnection(pPeer);
-    }
-  }
-
-  pthread_mutex_unlock(&(pNode->mutex));
+  taosReleaseRef(tsSyncRefId, pNode);
 
   return code;
 }
 
 void syncConfirmForward(void *param, uint64_t version, int32_t code) {
   SSyncNode *pNode = param;
-  if (pNode == NULL) return;
-  if (pNode->quorum <= 1) return;
 
-  SSyncPeer *pPeer = pNode->pMaster;
-  if (pPeer == NULL) return;
+  int ret = taosAcquireRef(tsSyncRefId, pNode);
+  if (ret < 0) return;
 
-  char msg[sizeof(SSyncHead) + sizeof(SFwdRsp)] = {0};
+  SSyncPeer *pPeer = pNode->pMaster;
+  if (pPeer && pNode->quorum > 1) {
+    char msg[sizeof(SSyncHead) + sizeof(SFwdRsp)] = {0};
 
-  SSyncHead *pHead = (SSyncHead *)msg;
-  pHead->type = TAOS_SMSG_FORWARD_RSP;
-  pHead->len = sizeof(SFwdRsp);
+    SSyncHead *pHead = (SSyncHead *)msg;
+    pHead->type = TAOS_SMSG_FORWARD_RSP;
+    pHead->len = sizeof(SFwdRsp);
 
-  SFwdRsp *pFwdRsp = (SFwdRsp *)(msg + sizeof(SSyncHead));
-  pFwdRsp->version = version;
-  pFwdRsp->code = code;
+    SFwdRsp *pFwdRsp = (SFwdRsp *)(msg + sizeof(SSyncHead));
+    pFwdRsp->version = version;
+    pFwdRsp->code = code;
 
-  int msgLen = sizeof(SSyncHead) + sizeof(SFwdRsp);
-  int retLen = write(pPeer->peerFd, msg, msgLen);
+    int msgLen = sizeof(SSyncHead) + sizeof(SFwdRsp);
+    int retLen = write(pPeer->peerFd, msg, msgLen);
 
-  if (retLen == msgLen) {
-    sDebug("%s, forward-rsp is sent, ver:%" PRIu64, pPeer->id, version);
-  } else {
-    sDebug("%s, failed to send forward ack, restart", pPeer->id);
-    syncRestartConnection(pPeer);
+    if (retLen == msgLen) {
+      sDebug("%s, forward-rsp is sent, ver:%" PRIu64, pPeer->id, version);
+    } else {
+      sDebug("%s, failed to send forward ack, restart", pPeer->id);
+      syncRestartConnection(pPeer);
+    }
   }
+
+  taosReleaseRef(tsSyncRefId, pNode);
 }
 
 void syncRecover(void *param) {
   SSyncNode *pNode = param;
   SSyncPeer *pPeer;
 
+  int ret = taosAcquireRef(tsSyncRefId, pNode);
+  if (ret < 0) return;
+
   // to do: add a few lines to check if recover is OK
   // if take this node to unsync state, the whole system may not work
 
@@ -414,17 +392,24 @@ void syncRecover(void *param) {
   }
 
   pthread_mutex_unlock(&(pNode->mutex));
+
+  taosReleaseRef(tsSyncRefId, pNode);
 }
 
 int syncGetNodesRole(void *param, SNodesRole *pNodesRole) {
   SSyncNode *pNode = param;
 
+  int ret = taosAcquireRef(tsSyncRefId, pNode);
+  if (ret < 0) return -1;
+
   pNodesRole->selfIndex = pNode->selfIndex;
   for (int i = 0; i < pNode->replica; ++i) {
     pNodesRole->nodeId[i] = pNode->peerInfo[i]->nodeId;
     pNodesRole->role[i] = pNode->peerInfo[i]->role;
   }
 
+  taosReleaseRef(tsSyncRefId, pNode);
+
   return 0;
 }
 
@@ -457,22 +442,20 @@ static void syncAddArbitrator(SSyncNode *pNode) {
   pNode->peerInfo[TAOS_SYNC_MAX_REPLICA] = syncAddPeer(pNode, &nodeInfo);
 }
 
-static void syncAddNodeRef(SSyncNode *pNode) { atomic_add_fetch_8(&pNode->refCount, 1); }
+static void syncFreeNode(void *param) {
+  SSyncNode *pNode = param;
 
-static void syncDecNodeRef(SSyncNode *pNode) {
-  if (atomic_sub_fetch_8(&pNode->refCount, 1) == 0) {
-    pthread_mutex_destroy(&pNode->mutex);
-    taosTFree(pNode->pRecv);
-    taosTFree(pNode->pSyncFwds);
-    taosTFree(pNode);
-  }
+  pthread_mutex_destroy(&pNode->mutex);
+  taosTFree(pNode->pRecv);
+  taosTFree(pNode->pSyncFwds);
+  taosTFree(pNode);
 }
 
 void syncAddPeerRef(SSyncPeer *pPeer) { atomic_add_fetch_8(&pPeer->refCount, 1); }
 
 int syncDecPeerRef(SSyncPeer *pPeer) {
   if (atomic_sub_fetch_8(&pPeer->refCount, 1) == 0) {
-    syncDecNodeRef(pPeer->pSyncNode);
+    taosReleaseRef(tsSyncRefId, pPeer->pSyncNode);
 
     sDebug("%s, resource is freed", pPeer->id);
     taosTFree(pPeer->watchFd);
@@ -529,7 +512,7 @@ static SSyncPeer *syncAddPeer(SSyncNode *pNode, const SNodeInfo *pInfo) {
     taosTmrReset(syncCheckPeerConnection, checkMs, pPeer, syncTmrCtrl, &pPeer->timer);
   }
 
-  syncAddNodeRef(pNode);
+  taosAcquireRef(tsSyncRefId, pNode);  
   return pPeer;
 }
 
@@ -1122,7 +1105,7 @@ static void syncProcessBrokenLink(void *param) {
   SSyncPeer *pPeer = param;
   SSyncNode *pNode = pPeer->pSyncNode;
 
-  syncAddNodeRef(pNode);
+  if (taosAcquireRef(tsSyncRefId, pNode) < 0) return;
   pthread_mutex_lock(&(pNode->mutex));
 
   sDebug("%s, TCP link is broken(%s)", pPeer->id, strerror(errno));
@@ -1133,7 +1116,7 @@ static void syncProcessBrokenLink(void *param) {
   }
 
   pthread_mutex_unlock(&(pNode->mutex));
-  syncDecNodeRef(pNode);
+  taosReleaseRef(tsSyncRefId, pNode);
 }
 
 static void syncSaveFwdInfo(SSyncNode *pNode, uint64_t version, void *mhandle) {
@@ -1202,22 +1185,90 @@ static void syncProcessFwdAck(SSyncNode *pNode, SFwdInfo *pFwdInfo, int32_t code
 
 static void syncMonitorFwdInfos(void *param, void *tmrId) {
   SSyncNode *pNode = param;
+
+  int ret = taosAcquireRef(tsSyncRefId, pNode);
+  if ( ret < 0) return;
+
   SSyncFwds *pSyncFwds = pNode->pSyncFwds;
-  if (pSyncFwds == NULL) return;
 
-  uint64_t   time = taosGetTimestampMs();
+  if (pSyncFwds) {;
+    uint64_t   time = taosGetTimestampMs();
 
-  if (pSyncFwds->fwds > 0) {
-    pthread_mutex_lock(&(pNode->mutex));
-    for (int i = 0; i < pSyncFwds->fwds; ++i) {
-      SFwdInfo *pFwdInfo = pSyncFwds->fwdInfo + (pSyncFwds->first + i) % tsMaxFwdInfo;
-      if (time - pFwdInfo->time < 2000) break;
-      syncProcessFwdAck(pNode, pFwdInfo, TSDB_CODE_RPC_NETWORK_UNAVAIL);
+    if (pSyncFwds->fwds > 0) {
+      pthread_mutex_lock(&(pNode->mutex));
+      for (int i = 0; i < pSyncFwds->fwds; ++i) {
+        SFwdInfo *pFwdInfo = pSyncFwds->fwdInfo + (pSyncFwds->first + i) % tsMaxFwdInfo;
+        if (time - pFwdInfo->time < 2000) break;
+        syncProcessFwdAck(pNode, pFwdInfo, TSDB_CODE_RPC_NETWORK_UNAVAIL);
+      }
+
+      syncRemoveConfirmedFwdInfo(pNode);
+      pthread_mutex_unlock(&(pNode->mutex));
     }
 
-    syncRemoveConfirmedFwdInfo(pNode);
-    pthread_mutex_unlock(&(pNode->mutex));
+    pNode->pFwdTimer = taosTmrStart(syncMonitorFwdInfos, 300, pNode, syncTmrCtrl);
   }
 
-  pNode->pFwdTimer = taosTmrStart(syncMonitorFwdInfos, 300, pNode, syncTmrCtrl);
+  taosReleaseRef(tsSyncRefId, pNode);
 }
+
+static int32_t syncForwardToPeerImpl(SSyncNode *pNode, void *data, void *mhandle, int qtype) {
+  SSyncPeer *pPeer;
+  SSyncHead *pSyncHead;
+  SWalHead * pWalHead = data;
+  int        fwdLen;
+  int32_t    code = 0;
+
+  if (nodeRole == TAOS_SYNC_ROLE_SLAVE && pWalHead->version != nodeVersion + 1) {
+    sError("vgId:%d, received ver:%" PRIu64 ", inconsistent with last ver:%" PRIu64 ", restart connection", pNode->vgId,
+           pWalHead->version, nodeVersion);
+    for (int i = 0; i < pNode->replica; ++i) {
+      pPeer = pNode->peerInfo[i];
+      syncRestartConnection(pPeer);
+    }
+    return TSDB_CODE_SYN_INVALID_VERSION;
+  }
+
+  // always update version
+  nodeVersion = pWalHead->version;
+  sDebug("vgId:%d, replica:%d nodeRole:%s qtype:%d ver:%" PRIu64, pNode->vgId, pNode->replica, syncRole[nodeRole],
+         qtype, pWalHead->version);
+
+  if (pNode->replica == 1 || nodeRole != TAOS_SYNC_ROLE_MASTER) return 0;
+
+  // only pkt from RPC or CQ can be forwarded
+  if (qtype != TAOS_QTYPE_RPC && qtype != TAOS_QTYPE_CQ) return 0;
+
+  // a hacker way to improve the performance
+  pSyncHead = (SSyncHead *)(((char *)pWalHead) - sizeof(SSyncHead));
+  pSyncHead->type = TAOS_SMSG_FORWARD;
+  pSyncHead->pversion = 0;
+  pSyncHead->len = sizeof(SWalHead) + pWalHead->len;
+  fwdLen = pSyncHead->len + sizeof(SSyncHead);  // include the WAL and SYNC head
+
+  pthread_mutex_lock(&(pNode->mutex));
+
+  for (int i = 0; i < pNode->replica; ++i) {
+    pPeer = pNode->peerInfo[i];
+    if (pPeer == NULL || pPeer->peerFd < 0) continue;
+    if (pPeer->role != TAOS_SYNC_ROLE_SLAVE && pPeer->sstatus != TAOS_SYNC_STATUS_CACHE) continue;
+
+    if (pNode->quorum > 1 && code == 0) {
+      syncSaveFwdInfo(pNode, pWalHead->version, mhandle);
+      code = 1;
+    }
+
+    int retLen = write(pPeer->peerFd, pSyncHead, fwdLen);
+    if (retLen == fwdLen) {
+      sDebug("%s, forward is sent, ver:%" PRIu64 " contLen:%d", pPeer->id, pWalHead->version, pWalHead->len);
+    } else {
+      sError("%s, failed to forward, ver:%" PRIu64 " retLen:%d", pPeer->id, pWalHead->version, retLen);
+      syncRestartConnection(pPeer);
+    }
+  }
+
+  pthread_mutex_unlock(&(pNode->mutex));
+
+  return code;
+}
+
diff --git a/tests/script/general/parser/join_multivnode.sim b/tests/script/general/parser/join_multivnode.sim
index 5e4a0990c18245dfda6c38cd65836e0d217444bf..102d5ba93fb79ff8874660b240c26937cce6dce7 100644
--- a/tests/script/general/parser/join_multivnode.sim
+++ b/tests/script/general/parser/join_multivnode.sim
@@ -134,13 +134,66 @@ sql select join_mt0.ts, join_mt1.t1, join_mt0.t1, join_mt1.tbname, join_mt0.tbna
 
 #1970-01-01 08:01:40.800 |                    10 |              45.000000000 |         0 |     true |     false |           0 |
 #1970-01-01 08:01:40.790 |                    10 |             945.000000000 |        90 |     true |      true |           0 |
-
 sql select count(join_mt0.c1), sum(join_mt1.c2), first(join_mt0.c5), last(join_mt1.c7), first(join_mt1.c7) from join_mt0, join_mt1 where join_mt0.t1=join_mt1.t1 and join_mt0.ts=join_mt1.ts interval(10a) group by join_mt0.t1 order by join_mt0.ts desc limit 20 offset 19;
-if $rows != 100 then
+if $rows != 20 then
+  return -1
+endi
+
+if $data00 != @70-01-01 08:01:40.800@ then
+  return -1
+endi
+
+if $data01 != 10 then
+  return -1
+endi
+
+if $data02 != 45.000000000 then
   return -1
 endi
 
-# c5 is null ! error
+if $data03 != 0 then
+  return -1
+endi
+
+if $data04 != 1 then
+  return -1
+endi
+
+if $data05 != 0 then
+  return -1
+endi
+
+if $data06 != 0 then
+  return -1
+endi
+
+if $data10 != @70-01-01 08:01:40.790@ then
+  return -1
+endi
+
+if $data11 != 10 then
+  return -1
+endi
+
+if $data12 != 945.000000000 then
+  return -1
+endi
+
+if $data13 != 90 then
+  return -1
+endi
+
+if $data14 != 1 then
+  return -1
+endi
+
+if $data15 != 1 then
+  return -1
+endi
+
+if $data16 != 0 then
+  return -1
+endi
 
 sql select count(join_mt0.c1), sum(join_mt0.c2)/count(*), avg(c2), first(join_mt0.c5), last(c7) from join_mt0  interval(10a) group by join_mt0.t1 order by join_mt0.ts desc;
 if $rows != 100 then