diff --git a/cmake/cmake.options b/cmake/cmake.options
index e84d02800c..e19c10f6b2 100644
--- a/cmake/cmake.options
+++ b/cmake/cmake.options
@@ -47,13 +47,13 @@ option(
 option(
     BUILD_WITH_UV
     "If build with libuv" 
-    OFF
+    ON  
 )
 
 option(
     BUILD_WITH_UV_TRANS
     "If build with libuv_trans " 
-    OFF 
+    ON 
 )
 
 option(
diff --git a/include/libs/transport/trpc.h b/include/libs/transport/trpc.h
index f913ba06d0..538aeb1a0e 100644
--- a/include/libs/transport/trpc.h
+++ b/include/libs/transport/trpc.h
@@ -64,6 +64,7 @@ typedef struct SRpcInit {
   int8_t   connType;      // TAOS_CONN_UDP, TAOS_CONN_TCPC, TAOS_CONN_TCPS
   int      idleTime;      // milliseconds, 0 means idle timer is disabled
 
+  bool noPool;  //  create conn pool or not
   // the following is for client app ecurity only
   char *user;     // user name
   char  spi;      // security parameter index
diff --git a/source/dnode/mgmt/impl/src/dndTransport.c b/source/dnode/mgmt/impl/src/dndTransport.c
index a0ba71a1eb..4e35baf905 100644
--- a/source/dnode/mgmt/impl/src/dndTransport.c
+++ b/source/dnode/mgmt/impl/src/dndTransport.c
@@ -155,7 +155,7 @@ static void dndInitMsgFp(STransMgmt *pMgmt) {
 }
 
 static void dndProcessResponse(void *parent, SRpcMsg *pRsp, SEpSet *pEpSet) {
-  SDnode     *pDnode = parent;
+  SDnode *    pDnode = parent;
   STransMgmt *pMgmt = &pDnode->tmgmt;
 
   tmsg_t msgType = pRsp->msgType;
@@ -193,6 +193,7 @@ static int32_t dndInitClient(SDnode *pDnode) {
   rpcInit.ckey = INTERNAL_CKEY;
   rpcInit.spi = 1;
   rpcInit.parent = pDnode;
+  rpcInit.noPool = true;
 
   char pass[TSDB_PASSWORD_LEN + 1] = {0};
   taosEncryptPass_c((uint8_t *)(INTERNAL_SECRET), strlen(INTERNAL_SECRET), pass);
@@ -218,7 +219,7 @@ static void dndCleanupClient(SDnode *pDnode) {
 }
 
 static void dndProcessRequest(void *param, SRpcMsg *pReq, SEpSet *pEpSet) {
-  SDnode     *pDnode = param;
+  SDnode *    pDnode = param;
   STransMgmt *pMgmt = &pDnode->tmgmt;
 
   tmsg_t msgType = pReq->msgType;
@@ -312,7 +313,7 @@ static int32_t dndRetrieveUserAuthInfo(void *parent, char *user, char *spi, char
   SAuthReq authReq = {0};
   tstrncpy(authReq.user, user, TSDB_USER_LEN);
   int32_t contLen = tSerializeSAuthReq(NULL, 0, &authReq);
-  void   *pReq = rpcMallocCont(contLen);
+  void *  pReq = rpcMallocCont(contLen);
   tSerializeSAuthReq(pReq, contLen, &authReq);
 
   SRpcMsg rpcMsg = {.pCont = pReq, .contLen = contLen, .msgType = TDMT_MND_AUTH, .ahandle = (void *)9528};
diff --git a/source/dnode/mgmt/impl/test/sut/inc/client.h b/source/dnode/mgmt/impl/test/sut/inc/client.h
index 9cf688fc02..925680d528 100644
--- a/source/dnode/mgmt/impl/test/sut/inc/client.h
+++ b/source/dnode/mgmt/impl/test/sut/inc/client.h
@@ -21,16 +21,21 @@ class TestClient {
   bool Init(const char* user, const char* pass, const char* fqdn, uint16_t port);
   void Cleanup();
 
+  void DoInit();
+
   SRpcMsg* SendReq(SRpcMsg* pReq);
   void     SetRpcRsp(SRpcMsg* pRsp);
   tsem_t*  GetSem();
+  void     Restart();
 
  private:
   char     fqdn[TSDB_FQDN_LEN];
   uint16_t port;
+  char     user[128];
+  char     pass[128];
   void*    clientRpc;
   SRpcMsg* pRsp;
   tsem_t   sem;
 };
 
-#endif /* _TD_TEST_CLIENT_H_ */
\ No newline at end of file
+#endif /* _TD_TEST_CLIENT_H_ */
diff --git a/source/dnode/mgmt/impl/test/sut/inc/sut.h b/source/dnode/mgmt/impl/test/sut/inc/sut.h
index 23913b0531..250d563a8b 100644
--- a/source/dnode/mgmt/impl/test/sut/inc/sut.h
+++ b/source/dnode/mgmt/impl/test/sut/inc/sut.h
@@ -20,10 +20,10 @@
 #include "os.h"
 
 #include "dnode.h"
-#include "tmsg.h"
 #include "tconfig.h"
 #include "tdataformat.h"
 #include "tglobal.h"
+#include "tmsg.h"
 #include "tnote.h"
 #include "trpc.h"
 #include "tthread.h"
@@ -39,6 +39,7 @@ class Testbase {
   void     Restart();
   void     ServerStop();
   void     ServerStart();
+  void     ClientRestart();
   SRpcMsg* SendReq(tmsg_t msgType, void* pCont, int32_t contLen);
 
  private:
@@ -100,7 +101,7 @@ class Testbase {
   {                                               \
     char* bytes = (char*)calloc(1, len);          \
     for (int32_t i = 0; i < len - 1; ++i) {       \
-      bytes[i] = b;                             \
+      bytes[i] = b;                               \
     }                                             \
     EXPECT_STREQ(test.GetShowBinary(len), bytes); \
   }
@@ -138,4 +139,4 @@ class Testbase {
 #define IgnoreTimestamp() \
   { test.GetShowTimestamp(); }
 
-#endif /* _TD_TEST_BASE_H_ */
\ No newline at end of file
+#endif /* _TD_TEST_BASE_H_ */
diff --git a/source/dnode/mgmt/impl/test/sut/src/client.cpp b/source/dnode/mgmt/impl/test/sut/src/client.cpp
index 8403dbf034..589c015013 100644
--- a/source/dnode/mgmt/impl/test/sut/src/client.cpp
+++ b/source/dnode/mgmt/impl/test/sut/src/client.cpp
@@ -13,33 +13,38 @@
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  */
 
-#include "tep.h"
 #include "sut.h"
+#include "tep.h"
 
 static void processClientRsp(void* parent, SRpcMsg* pRsp, SEpSet* pEpSet) {
   TestClient* client = (TestClient*)parent;
   client->SetRpcRsp(pRsp);
-  uInfo("response:%s from dnode, code:0x%x", TMSG_INFO(pRsp->msgType), pRsp->code);
+  uInfo("x response:%s from dnode, code:0x%x, msgSize: %d", TMSG_INFO(pRsp->msgType), pRsp->code, pRsp->contLen);
   tsem_post(client->GetSem());
 }
 
-void TestClient::SetRpcRsp(SRpcMsg* pRsp) { this->pRsp = pRsp; };
+void TestClient::SetRpcRsp(SRpcMsg* rsp) {
+  this->pRsp = (SRpcMsg*)calloc(1, sizeof(SRpcMsg));
+  this->pRsp->msgType = rsp->msgType;
+  this->pRsp->code = rsp->code;
+  this->pRsp->pCont = rsp->pCont;
+  this->pRsp->contLen = rsp->contLen;
+};
 
 tsem_t* TestClient::GetSem() { return &sem; }
 
-bool TestClient::Init(const char* user, const char* pass, const char* fqdn, uint16_t port) {
+void TestClient::DoInit() {
   char secretEncrypt[TSDB_PASSWORD_LEN + 1] = {0};
   taosEncryptPass_c((uint8_t*)pass, strlen(pass), secretEncrypt);
-
   SRpcInit rpcInit;
   memset(&rpcInit, 0, sizeof(rpcInit));
-  rpcInit.label = (char*)"DND-C";
+  rpcInit.label = (char*)"shell";
   rpcInit.numOfThreads = 1;
   rpcInit.cfp = processClientRsp;
   rpcInit.sessions = 1024;
   rpcInit.connType = TAOS_CONN_CLIENT;
   rpcInit.idleTime = 30 * 1000;
-  rpcInit.user = (char*)user;
+  rpcInit.user = (char*)this->user;
   rpcInit.ckey = (char*)"key";
   rpcInit.parent = this;
   rpcInit.secret = (char*)secretEncrypt;
@@ -47,11 +52,16 @@ bool TestClient::Init(const char* user, const char* pass, const char* fqdn, uint
 
   clientRpc = rpcOpen(&rpcInit);
   ASSERT(clientRpc);
+  tsem_init(&this->sem, 0, 0);
+}
 
-  tsem_init(&sem, 0, 0);
+bool TestClient::Init(const char* user, const char* pass, const char* fqdn, uint16_t port) {
   strcpy(this->fqdn, fqdn);
+  strcpy(this->user, user);
+  strcpy(this->pass, pass);
   this->port = port;
-
+  // this->pRsp = NULL;
+  this->DoInit();
   return true;
 }
 
@@ -60,11 +70,16 @@ void TestClient::Cleanup() {
   rpcClose(clientRpc);
 }
 
+void TestClient::Restart() {
+  this->Cleanup();
+  this->DoInit();
+}
 SRpcMsg* TestClient::SendReq(SRpcMsg* pReq) {
   SEpSet epSet = {0};
   addEpIntoEpSet(&epSet, fqdn, port);
   rpcSendRequest(clientRpc, &epSet, pReq, NULL);
   tsem_wait(&sem);
+  uInfo("y response:%s from dnode, code:0x%x, msgSize: %d", TMSG_INFO(pRsp->msgType), pRsp->code, pRsp->contLen);
 
   return pRsp;
 }
diff --git a/source/dnode/mgmt/impl/test/sut/src/sut.cpp b/source/dnode/mgmt/impl/test/sut/src/sut.cpp
index 09a738be3b..771c5886ef 100644
--- a/source/dnode/mgmt/impl/test/sut/src/sut.cpp
+++ b/source/dnode/mgmt/impl/test/sut/src/sut.cpp
@@ -21,9 +21,9 @@ void Testbase::InitLog(const char* path) {
   mDebugFlag = 143;
   cDebugFlag = 0;
   jniDebugFlag = 0;
-  tmrDebugFlag = 0;
-  uDebugFlag = 0;
-  rpcDebugFlag = 0;
+  tmrDebugFlag = 143;
+  uDebugFlag = 143;
+  rpcDebugFlag = 143;
   qDebugFlag = 0;
   wDebugFlag = 0;
   sDebugFlag = 0;
@@ -66,16 +66,21 @@ void Testbase::Init(const char* path, int16_t port) {
 
 void Testbase::Cleanup() {
   tFreeSTableMetaRsp(&metaRsp);
-  server.Stop();
   client.Cleanup();
+  taosMsleep(10);
+  server.Stop();
   dndCleanup();
 }
 
-void Testbase::Restart() { server.Restart(); }
+void Testbase::Restart() {
+  server.Restart();
+  client.Restart();
+}
 
 void Testbase::ServerStop() { server.Stop(); }
 
 void Testbase::ServerStart() { server.DoStart(); }
+void Testbase::ClientRestart() { client.Restart(); }
 
 SRpcMsg* Testbase::SendReq(tmsg_t msgType, void* pCont, int32_t contLen) {
   SRpcMsg rpcMsg = {0};
@@ -194,4 +199,4 @@ int32_t Testbase::GetShowRows() { return pRetrieveRsp->numOfRows; }
 
 STableMetaRsp* Testbase::GetShowMeta() { return &metaRsp; }
 
-SRetrieveTableRsp* Testbase::GetRetrieveRsp() { return pRetrieveRsp; }
\ No newline at end of file
+SRetrieveTableRsp* Testbase::GetRetrieveRsp() { return pRetrieveRsp; }
diff --git a/source/dnode/mnode/impl/src/mnode.c b/source/dnode/mnode/impl/src/mnode.c
index 699ccab92c..64b4aa6dd7 100644
--- a/source/dnode/mnode/impl/src/mnode.c
+++ b/source/dnode/mnode/impl/src/mnode.c
@@ -77,7 +77,7 @@ static void mndTransReExecute(void *param, void *tmrId) {
   SMnode *pMnode = param;
   if (mndIsMaster(pMnode)) {
     int32_t contLen = 0;
-    void   *pReq = mndBuildTimerMsg(&contLen);
+    void *  pReq = mndBuildTimerMsg(&contLen);
     SRpcMsg rpcMsg = {.msgType = TDMT_MND_TRANS, .pCont = pReq, .contLen = contLen};
     pMnode->putReqToMWriteQFp(pMnode->pDnode, &rpcMsg);
   }
@@ -89,7 +89,7 @@ static void mndCalMqRebalance(void *param, void *tmrId) {
   SMnode *pMnode = param;
   if (mndIsMaster(pMnode)) {
     int32_t contLen = 0;
-    void   *pReq = mndBuildTimerMsg(&contLen);
+    void *  pReq = mndBuildTimerMsg(&contLen);
     SRpcMsg rpcMsg = {.msgType = TDMT_MND_MQ_TIMER, .pCont = pReq, .contLen = contLen};
     pMnode->putReqToMReadQFp(pMnode->pDnode, &rpcMsg);
   }
@@ -404,7 +404,8 @@ SMnodeMsg *mndInitMsg(SMnode *pMnode, SRpcMsg *pRpcMsg) {
     return NULL;
   }
 
-  if (pRpcMsg->msgType != TDMT_MND_TRANS && pRpcMsg->msgType != TDMT_MND_MQ_TIMER && pRpcMsg->msgType != TDMT_MND_MQ_DO_REBALANCE) {
+  if (pRpcMsg->msgType != TDMT_MND_TRANS && pRpcMsg->msgType != TDMT_MND_MQ_TIMER &&
+      pRpcMsg->msgType != TDMT_MND_MQ_DO_REBALANCE) {
     SRpcConnInfo connInfo = {0};
     if ((pRpcMsg->msgType & 1U) && rpcGetConnInfo(pRpcMsg->handle, &connInfo) != 0) {
       taosFreeQitem(pMsg);
@@ -439,7 +440,7 @@ void mndProcessMsg(SMnodeMsg *pMsg) {
   SMnode *pMnode = pMsg->pMnode;
   int32_t code = 0;
   tmsg_t  msgType = pMsg->rpcMsg.msgType;
-  void   *ahandle = pMsg->rpcMsg.ahandle;
+  void *  ahandle = pMsg->rpcMsg.ahandle;
   bool    isReq = (msgType & 1U);
 
   mTrace("msg:%p, type:%s will be processed, app:%p", pMsg, TMSG_INFO(msgType), ahandle);
diff --git a/source/dnode/mnode/impl/test/qnode/qnode.cpp b/source/dnode/mnode/impl/test/qnode/qnode.cpp
index d4e308268a..b8a0e61ca3 100644
--- a/source/dnode/mnode/impl/test/qnode/qnode.cpp
+++ b/source/dnode/mnode/impl/test/qnode/qnode.cpp
@@ -190,6 +190,9 @@ TEST_F(MndTestQnode, 03_Create_Qnode_Rollback) {
     tSerializeSMCreateDropQSBNodeReq(pReq, contLen, &createReq);
 
     server2.Stop();
+    taosMsleep(1000);
+    // test.ClientRestart();
+
     SRpcMsg* pRsp = test.SendReq(TDMT_MND_CREATE_QNODE, pReq, contLen);
     ASSERT_NE(pRsp, nullptr);
     ASSERT_EQ(pRsp->code, TSDB_CODE_RPC_NETWORK_UNAVAIL);
@@ -226,6 +229,7 @@ TEST_F(MndTestQnode, 03_Create_Qnode_Rollback) {
   {
     // server start, wait until the rollback finished
     server2.DoStart();
+    test.ClientRestart();
     taosMsleep(1000);
 
     int32_t retry = 0;
@@ -248,7 +252,6 @@ TEST_F(MndTestQnode, 03_Create_Qnode_Rollback) {
     ASSERT_NE(retry, retryMax);
   }
 }
-
 TEST_F(MndTestQnode, 04_Drop_Qnode_Rollback) {
   {
     // send message first, then dnode2 crash, result is returned, and rollback is started
@@ -315,4 +318,4 @@ TEST_F(MndTestQnode, 04_Drop_Qnode_Rollback) {
 
     ASSERT_NE(retry, retryMax);
   }
-}
\ No newline at end of file
+}
diff --git a/source/dnode/mnode/impl/test/trans/trans.cpp b/source/dnode/mnode/impl/test/trans/trans.cpp
index d4c40dd428..88d4fc4f75 100644
--- a/source/dnode/mnode/impl/test/trans/trans.cpp
+++ b/source/dnode/mnode/impl/test/trans/trans.cpp
@@ -46,8 +46,10 @@ class MndTestTrans : public ::testing::Test {
     free(buffer);
     taosFsyncFile(fd);
     taosCloseFile(fd);
+    taosMsleep(1000);
 
     test.ServerStart();
+    test.ClientRestart();
   }
 
   static Testbase   test;
@@ -284,6 +286,7 @@ TEST_F(MndTestTrans, 03_Create_Qnode2_Crash) {
   }
 }
 
+
 // create db
 // partial create stb
 // drop db failed
diff --git a/source/dnode/mnode/impl/test/user/user.cpp b/source/dnode/mnode/impl/test/user/user.cpp
index d8ce599be1..61b99beeb7 100644
--- a/source/dnode/mnode/impl/test/user/user.cpp
+++ b/source/dnode/mnode/impl/test/user/user.cpp
@@ -617,6 +617,7 @@ TEST_F(MndTestUser, 06_Create_Drop_Alter_User) {
   // restart
   test.Restart();
 
+  taosMsleep(1000);
   test.SendShowMetaReq(TSDB_MGMT_TABLE_USER, "");
   CHECK_META("show users", 4);
 
@@ -631,4 +632,4 @@ TEST_F(MndTestUser, 06_Create_Drop_Alter_User) {
   CheckTimestamp();
   CheckBinary("root", TSDB_USER_LEN);
   CheckBinary("root", TSDB_USER_LEN);
-}
\ No newline at end of file
+}
diff --git a/source/libs/transport/inc/transComm.h b/source/libs/transport/inc/transComm.h
index d5a8cf5f84..2078a218ee 100644
--- a/source/libs/transport/inc/transComm.h
+++ b/source/libs/transport/inc/transComm.h
@@ -217,7 +217,7 @@ typedef struct SConnBuffer {
   char* buf;
   int   len;
   int   cap;
-  int   left;
+  int   total;
 } SConnBuffer;
 
 typedef void (*AsyncCB)(uv_async_t* handle);
diff --git a/source/libs/transport/inc/transportInt.h b/source/libs/transport/inc/transportInt.h
index 3c8c922d83..a36b671eb4 100644
--- a/source/libs/transport/inc/transportInt.h
+++ b/source/libs/transport/inc/transportInt.h
@@ -56,6 +56,7 @@ typedef struct {
   int8_t   connType;
   int64_t  index;
   char     label[TSDB_LABEL_LEN];
+  bool     noPool;  // pool or not
 
   char user[TSDB_UNI_LEN];         // meter ID
   char spi;                        // security parameter index
diff --git a/source/libs/transport/src/rpcMain.c b/source/libs/transport/src/rpcMain.c
index 3bb7d103d7..72c1ff6893 100644
--- a/source/libs/transport/src/rpcMain.c
+++ b/source/libs/transport/src/rpcMain.c
@@ -64,6 +64,7 @@ typedef struct {
   void (*cfp)(void *parent, SRpcMsg *, SEpSet *);
   int (*afp)(void *parent, char *user, char *spi, char *encrypt, char *secret, char *ckey);
 
+  bool             noPool;
   int32_t          refCount;
   void *           parent;
   void *           idPool;     // handle to ID pool
diff --git a/source/libs/transport/src/trans.c b/source/libs/transport/src/trans.c
index c3d3cfa2ab..48c15ca286 100644
--- a/source/libs/transport/src/trans.c
+++ b/source/libs/transport/src/trans.c
@@ -27,7 +27,7 @@ void* rpcOpen(const SRpcInit* pInit) {
     return NULL;
   }
   if (pInit->label) {
-    tstrncpy(pRpc->label, pInit->label, strlen(pInit->label));
+    tstrncpy(pRpc->label, pInit->label, strlen(pInit->label) + 1);
   }
   pRpc->cfp = pInit->cfp;
   if (pInit->connType == TAOS_CONN_SERVER) {
@@ -35,6 +35,8 @@ void* rpcOpen(const SRpcInit* pInit) {
   } else {
     pRpc->numOfThreads = pInit->numOfThreads;
   }
+
+  pRpc->noPool = pInit->noPool;
   pRpc->connType = pInit->connType;
   pRpc->idleTime = pInit->idleTime;
   pRpc->tcphandle = (*taosInitHandle[pRpc->connType])(0, pInit->localPort, pRpc->label, pRpc->numOfThreads, NULL, pRpc);
diff --git a/source/libs/transport/src/transCli.c b/source/libs/transport/src/transCli.c
index f1bd1ba980..c70cd933d5 100644
--- a/source/libs/transport/src/transCli.c
+++ b/source/libs/transport/src/transCli.c
@@ -126,6 +126,9 @@ static void clientHandleResp(SCliConn* conn) {
   pHead->code = htonl(pHead->code);
   pHead->msgLen = htonl(pHead->msgLen);
 
+  // buf's mem alread translated to rpcMsg.pCont
+  transClearBuffer(&conn->readBuf);
+
   SRpcMsg rpcMsg;
   rpcMsg.contLen = transContLenFromMsg(pHead->msgLen);
   rpcMsg.pCont = transContFromHead((char*)pHead);
@@ -134,15 +137,15 @@ static void clientHandleResp(SCliConn* conn) {
   rpcMsg.ahandle = pCtx->ahandle;
 
   if (rpcMsg.msgType == TDMT_VND_QUERY_RSP || rpcMsg.msgType == TDMT_VND_FETCH_RSP ||
-      rpcMsg.msgType == TDMT_VND_RES_READY) {
+      rpcMsg.msgType == TDMT_VND_RES_READY_RSP) {
     rpcMsg.handle = conn;
     conn->persist = 1;
     tDebug("client conn %p persist by app", conn);
   }
 
-  tDebug("client conn %p %s received from %s:%d, local info: %s:%d", conn, TMSG_INFO(pHead->msgType),
-         inet_ntoa(conn->addr.sin_addr), ntohs(conn->addr.sin_port), inet_ntoa(conn->locaddr.sin_addr),
-         ntohs(conn->locaddr.sin_port));
+  tDebug("%s client conn %p %s received from %s:%d, local info: %s:%d, msg size: %d", pRpc->label, conn,
+         TMSG_INFO(pHead->msgType), inet_ntoa(conn->addr.sin_addr), ntohs(conn->addr.sin_port),
+         inet_ntoa(conn->locaddr.sin_addr), ntohs(conn->locaddr.sin_port), rpcMsg.contLen);
 
   conn->secured = pHead->secured;
   if (conn->push != NULL && conn->ctnRdCnt != 0) {
@@ -150,26 +153,26 @@ static void clientHandleResp(SCliConn* conn) {
     conn->push = NULL;
   } else {
     if (pCtx->pSem == NULL) {
-      tTrace("client conn %p handle resp", conn);
+      tTrace("%s client conn %p handle resp", pRpc->label, conn);
       (pRpc->cfp)(pRpc->parent, &rpcMsg, NULL);
     } else {
-      tTrace("client conn(sync) %p handle resp", conn);
+      tTrace("%s client conn(sync) %p handle resp", pRpc->label, conn);
       memcpy((char*)pCtx->pRsp, (char*)&rpcMsg, sizeof(rpcMsg));
       tsem_post(pCtx->pSem);
     }
   }
   conn->ctnRdCnt += 1;
 
-  // buf's mem alread translated to rpcMsg.pCont
-  transClearBuffer(&conn->readBuf);
-
   uv_read_start((uv_stream_t*)conn->stream, clientAllocBufferCb, clientReadCb);
 
   SCliThrdObj* pThrd = conn->hostThrd;
 
   // user owns conn->persist = 1
   if (conn->push == NULL && conn->persist == 0) {
-    addConnToPool(pThrd->pool, pCtx->ip, pCtx->port, conn);
+    if (pRpc->noPool == true) {
+    } else {
+      addConnToPool(pThrd->pool, pCtx->ip, pCtx->port, conn);
+    }
   }
   destroyCmsg(conn->data);
   conn->data = NULL;
@@ -184,7 +187,6 @@ static void clientHandleExcept(SCliConn* pConn) {
     clientConnDestroy(pConn, true);
     return;
   }
-  tTrace("client conn %p start to destroy", pConn);
   SCliMsg* pMsg = pConn->data;
 
   tmsg_t msgType = TDMT_MND_CONNECT;
@@ -213,6 +215,7 @@ static void clientHandleExcept(SCliConn* pConn) {
     }
     pConn->push = NULL;
   }
+  tTrace("%s client conn %p start to destroy", pCtx->pTransInst->label, pConn);
   if (pConn->push == NULL) {
     destroyCmsg(pConn->data);
     pConn->data = NULL;
@@ -226,7 +229,7 @@ static void clientTimeoutCb(uv_timer_t* handle) {
   SCliThrdObj* pThrd = handle->data;
   SRpcInfo*    pRpc = pThrd->pTransInst;
   int64_t      currentTime = pThrd->nextTimeout;
-  tTrace("client conn timeout, try to remove expire conn from conn pool");
+  tTrace("%s, client conn timeout, try to remove expire conn from conn pool", pRpc->label);
 
   SConnList* p = taosHashIterate((SHashObj*)pThrd->pool, NULL);
   while (p != NULL) {
@@ -307,21 +310,30 @@ static void addConnToPool(void* pool, char* ip, uint32_t port, SCliConn* conn) {
   QUEUE_PUSH(&plist->conn, &conn->conn);
 }
 static bool clientReadComplete(SConnBuffer* data) {
-  STransMsgHead head;
-  int32_t       headLen = sizeof(head);
-  if (data->len >= headLen) {
-    memcpy((char*)&head, data->buf, headLen);
-    int32_t msgLen = (int32_t)htonl((uint32_t)head.msgLen);
-    if (msgLen > data->len) {
-      data->left = msgLen - data->len;
-      return false;
-    } else if (msgLen == data->len) {
-      data->left = 0;
-      return true;
-    }
-  } else {
-    return false;
+  if (data->len >= sizeof(STransMsgHead)) {
+    STransMsgHead head;
+    memcpy((char*)&head, data->buf, sizeof(head));
+    int32_t msgLen = (int32_t)htonl(head.msgLen);
+    data->total = msgLen;
   }
+
+  if (data->len == data->cap && data->total == data->cap) {
+    return true;
+  }
+  return false;
+  // if (data->len >= headLen) {
+  //  memcpy((char*)&head, data->buf, headLen);
+  //  int32_t msgLen = (int32_t)htonl((uint32_t)head.msgLen);
+  //  if (msgLen > data->len) {
+  //    data->left = msgLen - data->len;
+  //    return false;
+  //  } else if (msgLen == data->len) {
+  //    data->left = 0;
+  //    return true;
+  //  }
+  //} else {
+  //  return false;
+  //}
 }
 static void clientAllocBufferCb(uv_handle_t* handle, size_t suggested_size, uv_buf_t* buf) {
   SCliConn*    conn = handle->data;
@@ -338,7 +350,6 @@ static void clientReadCb(uv_stream_t* handle, ssize_t nread, const uv_buf_t* buf
   if (nread > 0) {
     pBuf->len += nread;
     if (clientReadComplete(pBuf)) {
-      uv_read_stop((uv_stream_t*)conn->stream);
       tTrace("client conn %p read complete", conn);
       clientHandleResp(conn);
     } else {
@@ -346,6 +357,10 @@ static void clientReadCb(uv_stream_t* handle, ssize_t nread, const uv_buf_t* buf
     }
     return;
   }
+  if (nread == UV_EOF) {
+    tError("client conn %p read error: %s", conn, uv_err_name(nread));
+    clientHandleExcept(conn);
+  }
   assert(nread <= 0);
   if (nread == 0) {
     // ref http://docs.libuv.org/en/v1.x/stream.html?highlight=uv_read_start#c.uv_read_cb
@@ -353,7 +368,7 @@ static void clientReadCb(uv_stream_t* handle, ssize_t nread, const uv_buf_t* buf
     // read(2).
     return;
   }
-  if (nread < 0 || nread == UV_EOF) {
+  if (nread < 0) {
     tError("client conn %p read error: %s", conn, uv_err_name(nread));
     clientHandleExcept(conn);
   }
@@ -467,6 +482,7 @@ static void clientConnCb(uv_connect_t* req, int status) {
 static void clientHandleQuit(SCliMsg* pMsg, SCliThrdObj* pThrd) {
   tDebug("client work thread %p start to quit", pThrd);
   destroyCmsg(pMsg);
+  destroyConnPool(pThrd->pool);
   // transDestroyAsyncPool(pThr) uv_close((uv_handle_t*)pThrd->cliAsync, NULL);
   uv_timer_stop(pThrd->timer);
   pThrd->quit = true;
@@ -483,7 +499,10 @@ static void clientHandleReq(SCliMsg* pMsg, SCliThrdObj* pThrd) {
 
   SCliConn* conn = NULL;
   if (pMsg->msg.handle == NULL) {
-    conn = getConnFromPool(pThrd->pool, pCtx->ip, pCtx->port);
+    if (pCtx->pTransInst->noPool == true) {
+    } else {
+      conn = getConnFromPool(pThrd->pool, pCtx->ip, pCtx->port);
+    }
     if (conn != NULL) {
       tTrace("client conn %p get from conn pool", conn);
     }
@@ -512,7 +531,11 @@ static void clientHandleReq(SCliMsg* pMsg, SCliThrdObj* pThrd) {
     conn->stream = (uv_stream_t*)malloc(sizeof(uv_tcp_t));
     uv_tcp_init(pThrd->loop, (uv_tcp_t*)(conn->stream));
     conn->stream->data = conn;
-
+    uv_tcp_nodelay((uv_tcp_t*)conn->stream, 1);
+    int ret = uv_tcp_keepalive((uv_tcp_t*)conn->stream, 1, 1);
+    if (ret) {
+      tTrace("client conn %p failed to set keepalive, %s", conn, uv_err_name(ret));
+    }
     // write req handle
     conn->writeReq = malloc(sizeof(uv_write_t));
     conn->writeReq->data = conn;
diff --git a/source/libs/transport/src/transComm.c b/source/libs/transport/src/transComm.c
index 7aa5aa16f1..388e0da4e0 100644
--- a/source/libs/transport/src/transComm.c
+++ b/source/libs/transport/src/transComm.c
@@ -205,6 +205,7 @@ int transInitBuffer(SConnBuffer* buf) {
 }
 int transClearBuffer(SConnBuffer* buf) {
   memset(buf, 0, sizeof(*buf));
+  buf->total = -1;
   return 0;
 }
 int transAllocBuffer(SConnBuffer* connBuf, uv_buf_t* uvBuf) {
@@ -214,27 +215,25 @@ int transAllocBuffer(SConnBuffer* connBuf, uv_buf_t* uvBuf) {
    * |<------STransMsgHead------->|<-------------------userdata--------------->|<-----auth data----->|<----user
    * info--->|
    */
-  static const int CAPACITY = 1024;
+  static const int CAPACITY = sizeof(STransMsgHead);
 
   SConnBuffer* p = connBuf;
   if (p->cap == 0) {
     p->buf = (char*)calloc(CAPACITY, sizeof(char));
     p->len = 0;
     p->cap = CAPACITY;
-    p->left = -1;
+    p->total = 0;
 
     uvBuf->base = p->buf;
     uvBuf->len = CAPACITY;
   } else {
-    if (p->len >= p->cap) {
-      if (p->left == -1) {
-        p->cap *= 2;
-        p->buf = realloc(p->buf, p->cap);
-      } else if (p->len + p->left > p->cap) {
-        p->cap = p->len + p->left;
-        p->buf = realloc(p->buf, p->len + p->left);
-      }
-    }
+    STransMsgHead head;
+    memcpy((char*)&head, p->buf, sizeof(head));
+    int32_t msgLen = (int32_t)htonl(head.msgLen);
+
+    p->total = msgLen;
+    p->cap = msgLen;
+    p->buf = realloc(p->buf, p->cap);
     uvBuf->base = p->buf + p->len;
     uvBuf->len = p->cap - p->len;
   }
diff --git a/source/libs/transport/src/transSrv.c b/source/libs/transport/src/transSrv.c
index 7ddeb99c9d..a038f72adc 100644
--- a/source/libs/transport/src/transSrv.c
+++ b/source/libs/transport/src/transSrv.c
@@ -61,6 +61,7 @@ typedef struct SWorkThrdObj {
   SAsyncPool* asyncPool;
   // uv_async_t*     workerAsync;  //
   queue           msg;
+  queue           conn;
   pthread_mutex_t msgMtx;
   void*           pTransInst;
 } SWorkThrdObj;
@@ -95,6 +96,7 @@ static void uvOnAcceptCb(uv_stream_t* stream, int status);
 static void uvOnConnectionCb(uv_stream_t* q, ssize_t nread, const uv_buf_t* buf);
 static void uvWorkerAsyncCb(uv_async_t* handle);
 static void uvAcceptAsyncCb(uv_async_t* handle);
+static void uvShutDownCb(uv_shutdown_t* req, int status);
 
 static void uvStartSendRespInternal(SSrvMsg* smsg);
 static void uvPrepareSendData(SSrvMsg* msg, uv_buf_t* wb);
@@ -103,7 +105,7 @@ static void uvStartSendResp(SSrvMsg* msg);
 static void destroySmsg(SSrvMsg* smsg);
 // check whether already read complete packet
 static bool      readComplete(SConnBuffer* buf);
-static SSrvConn* createConn();
+static SSrvConn* createConn(void* hThrd);
 static void      destroyConn(SSrvConn* conn, bool clear /*clear handle or not*/);
 
 static void uvDestroyConn(uv_handle_t* handle);
@@ -117,11 +119,6 @@ static bool addHandleToWorkloop(void* arg);
 static bool addHandleToAcceptloop(void* arg);
 
 void uvAllocReadBufferCb(uv_handle_t* handle, size_t suggested_size, uv_buf_t* buf) {
-  /*
-   * formate of data buffer:
-   * |<--------------------------data from socket------------------------------->|
-   * |<------STransMsgHead------->|<-------------------other data--------------->|
-   */
   SSrvConn*    conn = handle->data;
   SConnBuffer* pBuf = &conn->readBuf;
   transAllocBuffer(pBuf, buf);
@@ -131,23 +128,27 @@ void uvAllocReadBufferCb(uv_handle_t* handle, size_t suggested_size, uv_buf_t* b
 //
 static bool readComplete(SConnBuffer* data) {
   // TODO(yihao): handle pipeline later
-  STransMsgHead head;
-  int32_t       headLen = sizeof(head);
-  if (data->len >= headLen) {
-    memcpy((char*)&head, data->buf, headLen);
-    int32_t msgLen = (int32_t)htonl((uint32_t)head.msgLen);
-    if (msgLen > data->len) {
-      data->left = msgLen - data->len;
-      return false;
-    } else if (msgLen == data->len) {
-      return true;
-    } else if (msgLen < data->len) {
-      return false;
-      // handle other packet later
-    }
-  } else {
-    return false;
+  if (data->len == data->cap && data->total == data->cap) {
+    return true;
   }
+  return false;
+  // STransMsgHead head;
+  // int32_t       headLen = sizeof(head);
+  // if (data->len >= headLen) {
+  //  memcpy((char*)&head, data->buf, headLen);
+  //  int32_t msgLen = (int32_t)htonl((uint32_t)head.msgLen);
+  //  if (msgLen > data->len) {
+  //    data->left = msgLen - data->len;
+  //    return false;
+  //  } else if (msgLen == data->len) {
+  //    return true;
+  //  } else if (msgLen < data->len) {
+  //    return false;
+  //    // handle other packet later
+  //  }
+  //} else {
+  //  return false;
+  //}
 }
 
 // static void uvDoProcess(SRecvInfo* pRecv) {
@@ -241,7 +242,7 @@ static void uvHandleReq(SSrvConn* pConn) {
   }
 
   pConn->inType = pHead->msgType;
-  assert(transIsReq(pHead->msgType));
+  // assert(transIsReq(pHead->msgType));
 
   SRpcInfo* pRpc = (SRpcInfo*)p->shandle;
   pHead->code = htonl(pHead->code);
@@ -266,9 +267,9 @@ static void uvHandleReq(SSrvConn* pConn) {
 
   transClearBuffer(&pConn->readBuf);
   pConn->ref++;
-  tDebug("server conn %p %s received from %s:%d, local info: %s:%d", pConn, TMSG_INFO(rpcMsg.msgType),
+  tDebug("server conn %p %s received from %s:%d, local info: %s:%d, msg size: %d", pConn, TMSG_INFO(rpcMsg.msgType),
          inet_ntoa(pConn->addr.sin_addr), ntohs(pConn->addr.sin_port), inet_ntoa(pConn->locaddr.sin_addr),
-         ntohs(pConn->locaddr.sin_port));
+         ntohs(pConn->locaddr.sin_port), rpcMsg.contLen);
   (*(pRpc->cfp))(pRpc->parent, &rpcMsg, NULL);
   // uv_timer_start(pConn->pTimer, uvHandleActivityTimeout, pRpc->idleTime * 10000, 0);
   // auth
@@ -290,6 +291,14 @@ void uvOnReadCb(uv_stream_t* cli, ssize_t nread, const uv_buf_t* buf) {
     }
     return;
   }
+  if (nread == UV_EOF) {
+    tError("server conn %p read error: %s", conn, uv_err_name(nread));
+    if (conn->ref > 1) {
+      conn->ref++;  // ref > 1 signed that write is in progress
+    }
+    destroyConn(conn, true);
+    return;
+  }
   if (nread == 0) {
     return;
   }
@@ -302,8 +311,8 @@ void uvOnReadCb(uv_stream_t* cli, ssize_t nread, const uv_buf_t* buf) {
   }
 }
 void uvAllocConnBufferCb(uv_handle_t* handle, size_t suggested_size, uv_buf_t* buf) {
-  buf->base = malloc(sizeof(char));
   buf->len = 2;
+  buf->base = calloc(1, sizeof(char) * buf->len);
 }
 
 void uvOnTimeoutCb(uv_timer_t* handle) {
@@ -386,6 +395,7 @@ static void uvStartSendRespInternal(SSrvMsg* smsg) {
 static void uvStartSendResp(SSrvMsg* smsg) {
   // impl
   SSrvConn* pConn = smsg->pConn;
+  pConn->ref--;  //
   if (taosArrayGetSize(pConn->srvMsgs) > 0) {
     tDebug("server conn %p push data to client %s:%d, local info: %s:%d", pConn, inet_ntoa(pConn->addr.sin_addr),
            ntohs(pConn->addr.sin_port), inet_ntoa(pConn->locaddr.sin_addr), ntohs(pConn->locaddr.sin_port));
@@ -403,6 +413,16 @@ static void destroySmsg(SSrvMsg* smsg) {
   transFreeMsg(smsg->msg.pCont);
   free(smsg);
 }
+static void destroyAllConn(SWorkThrdObj* pThrd) {
+  while (!QUEUE_IS_EMPTY(&pThrd->conn)) {
+    queue* h = QUEUE_HEAD(&pThrd->conn);
+    QUEUE_REMOVE(h);
+    QUEUE_INIT(h);
+
+    SSrvConn* c = QUEUE_DATA(h, SSrvConn, queue);
+    destroyConn(c, true);
+  }
+}
 void uvWorkerAsyncCb(uv_async_t* handle) {
   SAsyncItem*   item = handle->data;
   SWorkThrdObj* pThrd = item->pThrd;
@@ -424,8 +444,11 @@ void uvWorkerAsyncCb(uv_async_t* handle) {
       continue;
     }
     if (msg->pConn == NULL) {
-      //
       free(msg);
+
+      destroyAllConn(pThrd);
+
+      uv_loop_close(pThrd->loop);
       uv_stop(pThrd->loop);
     } else {
       uvStartSendResp(msg);
@@ -439,9 +462,16 @@ void uvWorkerAsyncCb(uv_async_t* handle) {
 }
 static void uvAcceptAsyncCb(uv_async_t* async) {
   SServerObj* srv = async->data;
+  uv_close((uv_handle_t*)&srv->server, NULL);
   uv_stop(srv->loop);
 }
 
+static void uvShutDownCb(uv_shutdown_t* req, int status) {
+  tDebug("conn failed to shut down: %s", uv_err_name(status));
+  uv_close((uv_handle_t*)req->handle, uvDestroyConn);
+  free(req);
+}
+
 void uvOnAcceptCb(uv_stream_t* stream, int status) {
   if (status == -1) {
     return;
@@ -491,7 +521,7 @@ void uvOnConnectionCb(uv_stream_t* q, ssize_t nread, const uv_buf_t* buf) {
   uv_handle_type pending = uv_pipe_pending_type(pipe);
   assert(pending == UV_TCP);
 
-  SSrvConn* pConn = createConn();
+  SSrvConn* pConn = createConn(pThrd);
 
   pConn->pTransInst = pThrd->pTransInst;
   /* init conn timer*/
@@ -507,6 +537,9 @@ void uvOnConnectionCb(uv_stream_t* q, ssize_t nread, const uv_buf_t* buf) {
   uv_tcp_init(pThrd->loop, pConn->pTcp);
   pConn->pTcp->data = pConn;
 
+  // uv_tcp_nodelay(pConn->pTcp, 1);
+  // uv_tcp_keepalive(pConn->pTcp, 1, 1);
+
   // init write request, just
   pConn->pWriter = calloc(1, sizeof(uv_write_t));
   pConn->pWriter->data = pConn;
@@ -560,6 +593,9 @@ static bool addHandleToWorkloop(void* arg) {
   QUEUE_INIT(&pThrd->msg);
   pthread_mutex_init(&pThrd->msgMtx, NULL);
 
+  // conn set
+  QUEUE_INIT(&pThrd->conn);
+
   pThrd->asyncPool = transCreateAsyncPool(pThrd->loop, 4, pThrd, uvWorkerAsyncCb);
   uv_read_start((uv_stream_t*)pThrd->pipe, uvAllocConnBufferCb, uvOnConnectionCb);
   return true;
@@ -598,8 +634,13 @@ void* workerThread(void* arg) {
   uv_run(pThrd->loop, UV_RUN_DEFAULT);
 }
 
-static SSrvConn* createConn() {
+static SSrvConn* createConn(void* hThrd) {
+  SWorkThrdObj* pThrd = hThrd;
+
   SSrvConn* pConn = (SSrvConn*)calloc(1, sizeof(SSrvConn));
+  QUEUE_INIT(&pConn->queue);
+
+  QUEUE_PUSH(&pThrd->conn, &pConn->queue);
   pConn->srvMsgs = taosArrayInit(2, sizeof(void*));  //
   tTrace("conn %p created", pConn);
   ++pConn->ref;
@@ -610,7 +651,7 @@ static void destroyConn(SSrvConn* conn, bool clear) {
   if (conn == NULL) {
     return;
   }
-  tTrace("server conn %p try to destroy", conn);
+  tTrace("server conn %p try to destroy, ref: %d", conn, conn->ref);
   if (--conn->ref > 0) {
     return;
   }
@@ -621,20 +662,23 @@ static void destroyConn(SSrvConn* conn, bool clear) {
     destroySmsg(msg);
   }
   taosArrayDestroy(conn->srvMsgs);
-
-  // destroySmsg(conn->pSrvMsg);
-  // conn->pSrvMsg = NULL;
+  QUEUE_REMOVE(&conn->queue);
 
   if (clear) {
-    uv_close((uv_handle_t*)conn->pTcp, uvDestroyConn);
+    tTrace("try to destroy conn %p", conn);
+    uv_tcp_close_reset(conn->pTcp, uvDestroyConn);
+    // uv_shutdown_t* req = malloc(sizeof(uv_shutdown_t));
+    // uv_shutdown(req, (uv_stream_t*)conn->pTcp, uvShutDownCb);
+    // uv_unref((uv_handle_t*)conn->pTcp);
+    // uv_close((uv_handle_t*)conn->pTcp, uvDestroyConn);
   }
 }
 static void uvDestroyConn(uv_handle_t* handle) {
   SSrvConn* conn = handle->data;
   tDebug("server conn %p destroy", conn);
   uv_timer_stop(conn->pTimer);
-  free(conn->pTimer);
-  // free(conn->pTcp);
+  // free(conn->pTimer);
+  free(conn->pTcp);
   free(conn->pWriter);
   free(conn);
 }
diff --git a/source/libs/transport/test/transUT.cc b/source/libs/transport/test/transUT.cc
index 6f80ea42ac..d1fefe2c72 100644
--- a/source/libs/transport/test/transUT.cc
+++ b/source/libs/transport/test/transUT.cc
@@ -16,69 +16,168 @@
 #include <cstdio>
 #include <cstring>
 #include "tep.h"
+#include "tglobal.h"
 #include "trpc.h"
+#include "ulog.h"
 using namespace std;
 
-class TransObj {
- public:
-  TransObj() {
-    const char *label = "APP";
-    const char *secret = "secret";
-    const char *user = "user";
-    const char *ckey = "ckey";
+const char *label = "APP";
+const char *secret = "secret";
+const char *user = "user";
+const char *ckey = "ckey";
 
+class Server;
+int port = 7000;
+// server process
+static void processReq(void *parent, SRpcMsg *pMsg, SEpSet *pEpSet);
+// client process;
+static void processResp(void *parent, SRpcMsg *pMsg, SEpSet *pEpSet);
+class Client {
+ public:
+  void Init(int nThread) {
     memset(&rpcInit, 0, sizeof(rpcInit));
     rpcInit.localPort = 0;
     rpcInit.label = (char *)label;
-    rpcInit.numOfThreads = 5;
-    rpcInit.cfp = NULL;
-    rpcInit.sessions = 100;
-    rpcInit.idleTime = 100;
+    rpcInit.numOfThreads = nThread;
+    rpcInit.cfp = processResp;
     rpcInit.user = (char *)user;
     rpcInit.secret = (char *)secret;
     rpcInit.ckey = (char *)ckey;
     rpcInit.spi = 1;
-  }
-  bool startCli() {
-    trans = NULL;
+    rpcInit.parent = this;
     rpcInit.connType = TAOS_CONN_CLIENT;
-    trans = rpcOpen(&rpcInit);
-    return trans != NULL ? true : false;
+    this->transCli = rpcOpen(&rpcInit);
+    tsem_init(&this->sem, 0, 0);
   }
-  bool startSrv() {
-    trans = NULL;
-    rpcInit.connType = TAOS_CONN_SERVER;
-    trans = rpcOpen(&rpcInit);
-    return trans != NULL ? true : false;
+  void SetResp(SRpcMsg *pMsg) {
+    // set up resp;
+    this->resp = *pMsg;
+  }
+  SRpcMsg *Resp() { return &this->resp; }
+
+  void Restart() {
+    rpcClose(this->transCli);
+    this->transCli = rpcOpen(&rpcInit);
   }
 
-  bool sendAndRecv() {
+  void SendAndRecv(SRpcMsg *req, SRpcMsg *resp) {
     SEpSet epSet = {0};
     epSet.inUse = 0;
-    addEpIntoEpSet(&epSet, "192.168.1.1", 7000);
-    addEpIntoEpSet(&epSet, "192.168.0.1", 7000);
+    addEpIntoEpSet(&epSet, "127.0.0.1", 7000);
 
-    if (trans == NULL) {
-      return false;
-    }
-    SRpcMsg rpcMsg = {0}, reqMsg = {0};
-    reqMsg.pCont = rpcMallocCont(10);
-    reqMsg.contLen = 10;
-    reqMsg.ahandle = NULL;
-    rpcSendRecv(trans, &epSet, &reqMsg, &rpcMsg);
-    int code = rpcMsg.code;
-    std::cout << tstrerror(code) << std::endl;
-    return true;
+    rpcSendRequest(this->transCli, &epSet, req, NULL);
+    SemWait();
+    *resp = this->resp;
   }
-  bool stop() {
-    rpcClose(trans);
-    trans = NULL;
-    return true;
+  void SemWait() { tsem_wait(&this->sem); }
+  void SemPost() { tsem_post(&this->sem); }
+  void Reset() {}
+
+  ~Client() {
+    if (this->transCli) rpcClose(this->transCli);
   }
 
  private:
-  void *   trans;
+  tsem_t   sem;
   SRpcInit rpcInit;
+  void *   transCli;
+  SRpcMsg  resp;
+};
+class Server {
+ public:
+  Server() {
+    memset(&rpcInit, 0, sizeof(rpcInit));
+    rpcInit.localPort = port;
+    rpcInit.label = (char *)label;
+    rpcInit.numOfThreads = 5;
+    rpcInit.cfp = processReq;
+    rpcInit.user = (char *)user;
+    rpcInit.secret = (char *)secret;
+    rpcInit.ckey = (char *)ckey;
+    rpcInit.spi = 1;
+    rpcInit.connType = TAOS_CONN_SERVER;
+  }
+  void Start() {
+    this->transSrv = rpcOpen(&this->rpcInit);
+    taosMsleep(1000);
+  }
+  void Stop() {
+    if (this->transSrv == NULL) return;
+    rpcClose(this->transSrv);
+    this->transSrv = NULL;
+  }
+  void Restart() {
+    this->Stop();
+    this->Start();
+  }
+  ~Server() {
+    if (this->transSrv) rpcClose(this->transSrv);
+    this->transSrv = NULL;
+  }
+
+ private:
+  SRpcInit rpcInit;
+  void *   transSrv;
+};
+static void processReq(void *parent, SRpcMsg *pMsg, SEpSet *pEpSet) {
+  SRpcMsg rpcMsg = {0};
+  rpcMsg.pCont = rpcMallocCont(100);
+  rpcMsg.contLen = 100;
+  rpcMsg.handle = pMsg->handle;
+  rpcMsg.code = 0;
+  rpcSendResponse(&rpcMsg);
+}
+// client process;
+static void processResp(void *parent, SRpcMsg *pMsg, SEpSet *pEpSet) {
+  Client *client = (Client *)parent;
+  client->SetResp(pMsg);
+  client->SemPost();
+}
+class TransObj {
+ public:
+  TransObj() {
+    dDebugFlag = 143;
+    vDebugFlag = 0;
+    mDebugFlag = 143;
+    cDebugFlag = 0;
+    jniDebugFlag = 0;
+    tmrDebugFlag = 143;
+    uDebugFlag = 143;
+    rpcDebugFlag = 143;
+    qDebugFlag = 0;
+    wDebugFlag = 0;
+    sDebugFlag = 0;
+    tsdbDebugFlag = 0;
+    cqDebugFlag = 0;
+    tscEmbeddedInUtil = 1;
+    tsAsyncLog = 0;
+
+    std::string path = "/tmp/transport";
+    taosRemoveDir(path.c_str());
+    taosMkDir(path.c_str());
+
+    char temp[PATH_MAX];
+    snprintf(temp, PATH_MAX, "%s/taosdlog", path.c_str());
+    if (taosInitLog(temp, tsNumOfLogLines, 1) != 0) {
+      printf("failed to init log file\n");
+    }
+    cli = new Client;
+    cli->Init(1);
+    srv = new Server;
+    srv->Start();
+  }
+  void RestartCli() { cli->Restart(); }
+  void StopSrv() { srv->Stop(); }
+  void RestartSrv() { srv->Restart(); }
+  void cliSendAndRecv(SRpcMsg *req, SRpcMsg *resp) { cli->SendAndRecv(req, resp); }
+  ~TransObj() {
+    delete cli;
+    delete srv;
+  }
+
+ private:
+  Client *cli;
+  Server *srv;
 };
 class TransEnv : public ::testing::Test {
  protected:
@@ -93,11 +192,34 @@ class TransEnv : public ::testing::Test {
 
   TransObj *tr = NULL;
 };
-TEST_F(TransEnv, test_start_stop) {
-  assert(tr->startCli());
-  assert(tr->sendAndRecv());
-  assert(tr->stop());
 
-  assert(tr->startSrv());
-  assert(tr->stop());
+// TEST_F(TransEnv, 01sendAndRec) {
+//  for (int i = 0; i < 1; i++) {
+//    SRpcMsg req = {0}, resp = {0};
+//    req.msgType = 0;
+//    req.pCont = rpcMallocCont(10);
+//    req.contLen = 10;
+//    tr->cliSendAndRecv(&req, &resp);
+//    assert(resp.code == 0);
+//  }
+//}
+
+TEST_F(TransEnv, 02StopServer) {
+  for (int i = 0; i < 1; i++) {
+    SRpcMsg req = {0}, resp = {0};
+    req.msgType = 0;
+    req.pCont = rpcMallocCont(10);
+    req.contLen = 10;
+    tr->cliSendAndRecv(&req, &resp);
+    assert(resp.code == 0);
+  }
+  SRpcMsg req = {0}, resp = {0};
+  req.msgType = 1;
+  req.pCont = rpcMallocCont(10);
+  req.contLen = 10;
+  tr->StopSrv();
+  // tr->RestartSrv();
+  tr->cliSendAndRecv(&req, &resp);
+
+  assert(resp.code != 0);
 }
diff --git a/source/os/src/osTimer.c b/source/os/src/osTimer.c
index 7e542ef80f..bb526e0ba0 100644
--- a/source/os/src/osTimer.c
+++ b/source/os/src/osTimer.c
@@ -22,13 +22,12 @@
  * windows implementation
  */
 
-
-#include <Windows.h>
 #include <Mmsystem.h>
-#include <stdio.h>
+#include <Windows.h>
 #include <stdint.h>
+#include <stdio.h>
 
-#pragma warning( disable : 4244 )
+#pragma warning(disable : 4244)
 
 typedef void (*win_timer_f)(int signo);
 
@@ -40,8 +39,8 @@ void WINAPI taosWinOnTimer(UINT wTimerID, UINT msg, DWORD_PTR dwUser, DWORD_PTR
 }
 
 static MMRESULT timerId;
-int taosInitTimer(win_timer_f callback, int ms) {
-  DWORD_PTR param = *((int64_t *) & callback);
+int             taosInitTimer(win_timer_f callback, int ms) {
+  DWORD_PTR param = *((int64_t *)&callback);
 
   timerId = timeSetEvent(ms, 1, (LPTIMECALLBACK)taosWinOnTimer, param, TIME_PERIODIC);
   if (timerId == 0) {
@@ -50,9 +49,7 @@ int taosInitTimer(win_timer_f callback, int ms) {
   return 0;
 }
 
-void taosUninitTimer() {
-  timeKillEvent(timerId);
-}
+void taosUninitTimer() { timeKillEvent(timerId); }
 
 #elif defined(_TD_DARWIN_64)
 
@@ -60,32 +57,32 @@ void taosUninitTimer() {
  * darwin implementation
  */
 
-#include <sys/syscall.h>
 #include <sys/event.h>
+#include <sys/syscall.h>
 #include <unistd.h>
 
 static void (*timer_callback)(int);
-static int           timer_ms = 0;
-static pthread_t     timer_thread;
-static int           timer_kq = -1;
-static volatile int  timer_stop = 0;
+static int          timer_ms = 0;
+static pthread_t    timer_thread;
+static int          timer_kq = -1;
+static volatile int timer_stop = 0;
 
-static void* timer_routine(void *arg) {
+static void* timer_routine(void* arg) {
   (void)arg;
   setThreadName("timer");
 
-  int r = 0;
+  int             r = 0;
   struct timespec to = {0};
-  to.tv_sec    = timer_ms / 1000;
-  to.tv_nsec   = (timer_ms % 1000) * 1000000;
+  to.tv_sec = timer_ms / 1000;
+  to.tv_nsec = (timer_ms % 1000) * 1000000;
   while (!timer_stop) {
     struct kevent64_s kev[10] = {0};
-    r = kevent64(timer_kq, NULL, 0, kev, sizeof(kev)/sizeof(kev[0]), 0, &to);
-    if (r!=0) {
+    r = kevent64(timer_kq, NULL, 0, kev, sizeof(kev) / sizeof(kev[0]), 0, &to);
+    if (r != 0) {
       fprintf(stderr, "==%s[%d]%s()==kevent64 failed\n", basename(__FILE__), __LINE__, __func__);
       abort();
     }
-    timer_callback(SIGALRM); // just mock
+    timer_callback(SIGALRM);  // just mock
   }
 
   return NULL;
@@ -93,11 +90,13 @@ static void* timer_routine(void *arg) {
 
 int taosInitTimer(void (*callback)(int), int ms) {
   int r = 0;
-  timer_ms       = ms;
+  timer_kq = -1;
+  timer_stop = 0;
+  timer_ms = ms;
   timer_callback = callback;
 
   timer_kq = kqueue();
-  if (timer_kq==-1) {
+  if (timer_kq == -1) {
     fprintf(stderr, "==%s[%d]%s()==failed to create timer kq\n", basename(__FILE__), __LINE__, __func__);
     // since no caller of this func checks the return value for the moment
     abort();
@@ -144,10 +143,10 @@ static void taosDeleteTimer(void *tharg) {
   timer_delete(*pTimer);
 }
 
-static pthread_t timerThread;
-static timer_t         timerId;
+static pthread_t     timerThread;
+static timer_t       timerId;
 static volatile bool stopTimer = false;
-static void *taosProcessAlarmSignal(void *tharg) {
+static void *        taosProcessAlarmSignal(void *tharg) {
   // Block the signal
   sigset_t sigset;
   sigemptyset(&sigset);
@@ -159,18 +158,18 @@ static void *taosProcessAlarmSignal(void *tharg) {
 
   setThreadName("tmr");
 
-  #ifdef _ALPINE
-    sevent.sigev_notify = SIGEV_THREAD;
-    sevent.sigev_value.sival_int = syscall(__NR_gettid);
-  #else
-    sevent.sigev_notify = SIGEV_THREAD_ID;
-    sevent._sigev_un._tid = syscall(__NR_gettid);
-  #endif
-  
+#ifdef _ALPINE
+  sevent.sigev_notify = SIGEV_THREAD;
+  sevent.sigev_value.sival_int = syscall(__NR_gettid);
+#else
+  sevent.sigev_notify = SIGEV_THREAD_ID;
+  sevent._sigev_un._tid = syscall(__NR_gettid);
+#endif
+
   sevent.sigev_signo = SIGALRM;
 
   if (timer_create(CLOCK_REALTIME, &sevent, &timerId) == -1) {
-    //printf("Failed to create timer");
+    // printf("Failed to create timer");
   }
 
   pthread_cleanup_push(taosDeleteTimer, &timerId);
@@ -182,36 +181,37 @@ static void *taosProcessAlarmSignal(void *tharg) {
   ts.it_interval.tv_nsec = 1000000 * MSECONDS_PER_TICK;
 
   if (timer_settime(timerId, 0, &ts, NULL)) {
-    //printf("Failed to init timer");
+    // printf("Failed to init timer");
     return NULL;
   }
 
   int signo;
   while (!stopTimer) {
     if (sigwait(&sigset, &signo)) {
-      //printf("Failed to wait signal: number %d", signo);
+      // printf("Failed to wait signal: number %d", signo);
       continue;
     }
     /* //printf("Signal handling: number %d ......\n", signo); */
 
     callback(0);
   }
-  
+
   pthread_cleanup_pop(1);
 
   return NULL;
 }
 
 int taosInitTimer(void (*callback)(int), int ms) {
+  stopTimer = false;
   pthread_attr_t tattr;
   pthread_attr_init(&tattr);
   int code = pthread_create(&timerThread, &tattr, taosProcessAlarmSignal, callback);
   pthread_attr_destroy(&tattr);
   if (code != 0) {
-    //printf("failed to create timer thread");
+    // printf("failed to create timer thread");
     return -1;
   } else {
-    //printf("timer thread:0x%08" PRIx64 " is created", taosGetPthreadId(timerThread));
+    // printf("timer thread:0x%08" PRIx64 " is created", taosGetPthreadId(timerThread));
   }
 
   return 0;
@@ -220,7 +220,7 @@ int taosInitTimer(void (*callback)(int), int ms) {
 void taosUninitTimer() {
   stopTimer = true;
 
-  //printf("join timer thread:0x%08" PRIx64, taosGetPthreadId(timerThread));
+  // printf("join timer thread:0x%08" PRIx64, taosGetPthreadId(timerThread));
   pthread_join(timerThread, NULL);
 }
 
diff --git a/source/util/src/ttimer.c b/source/util/src/ttimer.c
index 1fdc2257d7..65101a5e07 100644
--- a/source/util/src/ttimer.c
+++ b/source/util/src/ttimer.c
@@ -13,19 +13,49 @@
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include "ttimer.h"
 #include "os.h"
+#include "taoserror.h"
 #include "tlog.h"
 #include "tsched.h"
-#include "ttimer.h"
 #include "tutil.h"
-#include "taoserror.h"
 
-#define tmrFatal(...) { if (tmrDebugFlag & DEBUG_FATAL) { taosPrintLog("TMR FATAL ", tmrDebugFlag, __VA_ARGS__); }}
-#define tmrError(...) { if (tmrDebugFlag & DEBUG_ERROR) { taosPrintLog("TMR ERROR ", tmrDebugFlag, __VA_ARGS__); }}
-#define tmrWarn(...)  { if (tmrDebugFlag & DEBUG_WARN)  { taosPrintLog("TMR WARN ", tmrDebugFlag, __VA_ARGS__); }}
-#define tmrInfo(...)  { if (tmrDebugFlag & DEBUG_INFO)  { taosPrintLog("TMR ", tmrDebugFlag, __VA_ARGS__); }}
-#define tmrDebug(...) { if (tmrDebugFlag & DEBUG_DEBUG) { taosPrintLog("TMR ", tmrDebugFlag, __VA_ARGS__); }}
-#define tmrTrace(...) { if (tmrDebugFlag & DEBUG_TRACE) { taosPrintLog("TMR ", tmrDebugFlag, __VA_ARGS__); }}
+#define tmrFatal(...)                                        \
+  {                                                          \
+    if (tmrDebugFlag & DEBUG_FATAL) {                        \
+      taosPrintLog("TMR FATAL ", tmrDebugFlag, __VA_ARGS__); \
+    }                                                        \
+  }
+#define tmrError(...)                                        \
+  {                                                          \
+    if (tmrDebugFlag & DEBUG_ERROR) {                        \
+      taosPrintLog("TMR ERROR ", tmrDebugFlag, __VA_ARGS__); \
+    }                                                        \
+  }
+#define tmrWarn(...)                                        \
+  {                                                         \
+    if (tmrDebugFlag & DEBUG_WARN) {                        \
+      taosPrintLog("TMR WARN ", tmrDebugFlag, __VA_ARGS__); \
+    }                                                       \
+  }
+#define tmrInfo(...)                                   \
+  {                                                    \
+    if (tmrDebugFlag & DEBUG_INFO) {                   \
+      taosPrintLog("TMR ", tmrDebugFlag, __VA_ARGS__); \
+    }                                                  \
+  }
+#define tmrDebug(...)                                  \
+  {                                                    \
+    if (tmrDebugFlag & DEBUG_DEBUG) {                  \
+      taosPrintLog("TMR ", tmrDebugFlag, __VA_ARGS__); \
+    }                                                  \
+  }
+#define tmrTrace(...)                                  \
+  {                                                    \
+    if (tmrDebugFlag & DEBUG_TRACE) {                  \
+      taosPrintLog("TMR ", tmrDebugFlag, __VA_ARGS__); \
+    }                                                  \
+  }
 
 #define TIMER_STATE_WAITING 0
 #define TIMER_STATE_EXPIRED 1
@@ -81,7 +111,7 @@ typedef struct time_wheel_t {
   tmr_obj_t**     slots;
 } time_wheel_t;
 
-int32_t tmrDebugFlag = 131;
+int32_t  tmrDebugFlag = 131;
 uint32_t tsMaxTmrCtrl = 512;
 
 static pthread_once_t  tmrModuleInit = PTHREAD_ONCE_INIT;
@@ -91,7 +121,7 @@ static tmr_ctrl_t*     unusedTmrCtrl = NULL;
 static void*           tmrQhandle;
 static int             numOfTmrCtrl = 0;
 
-int taosTmrThreads = 1;
+int              taosTmrThreads = 1;
 static uintptr_t nextTimerId = 0;
 
 static time_wheel_t wheels[] = {
@@ -119,7 +149,7 @@ static void timerDecRef(tmr_obj_t* timer) {
 
 static void lockTimerList(timer_list_t* list) {
   int64_t tid = taosGetSelfPthreadId();
-  int       i = 0;
+  int     i = 0;
   while (atomic_val_compare_exchange_64(&(list->lockedBy), 0, tid) != 0) {
     if (++i % 1000 == 0) {
       sched_yield();
@@ -276,11 +306,11 @@ static void addToExpired(tmr_obj_t* head) {
   const char* fmt = "%s adding expired timer[id=%" PRIuPTR ", fp=%p, param=%p] to queue.";
 
   while (head != NULL) {
-    uintptr_t id = head->id;
+    uintptr_t  id = head->id;
     tmr_obj_t* next = head->next;
     tmrDebug(fmt, head->ctrl->label, id, head->fp, head->param);
 
-    SSchedMsg  schedMsg;
+    SSchedMsg schedMsg;
     schedMsg.fp = NULL;
     schedMsg.tfp = processExpiredTimer;
     schedMsg.msg = NULL;
@@ -491,6 +521,8 @@ static void taosTmrModuleInit(void) {
     return;
   }
 
+  memset(&timerMap, 0, sizeof(timerMap));
+
   for (uint32_t i = 0; i < tsMaxTmrCtrl - 1; ++i) {
     tmr_ctrl_t* ctrl = tmrCtrls + i;
     ctrl->next = ctrl + 1;
@@ -570,7 +602,8 @@ void taosTmrCleanUp(void* handle) {
   unusedTmrCtrl = ctrl;
   pthread_mutex_unlock(&tmrCtrlMutex);
 
-  if (numOfTmrCtrl <=0) {
+  tmrDebug("time controller's tmr ctrl size:  %d", numOfTmrCtrl);
+  if (numOfTmrCtrl <= 0) {
     taosUninitTimer();
 
     taosCleanUpScheduler(tmrQhandle);
@@ -585,7 +618,7 @@ void taosTmrCleanUp(void* handle) {
 
     for (size_t i = 0; i < timerMap.size; i++) {
       timer_list_t* list = timerMap.slots + i;
-      tmr_obj_t* t = list->timers;
+      tmr_obj_t*    t = list->timers;
       while (t != NULL) {
         tmr_obj_t* next = t->mnext;
         free(t);
@@ -595,6 +628,8 @@ void taosTmrCleanUp(void* handle) {
     free(timerMap.slots);
     free(tmrCtrls);
 
-    tmrDebug("timer module is cleaned up");
+    tmrCtrls = NULL;
+    unusedTmrCtrl = NULL;
+    tmrModuleInit = PTHREAD_ONCE_INIT;  // to support restart
   }
 }