diff --git a/source/libs/transport/inc/transComm.h b/source/libs/transport/inc/transComm.h
index c760acd52e80443d2a4bb7b5874ce7258e687798..f0b54a82e75888bd45b237b9a439a66c0732f112 100644
--- a/source/libs/transport/inc/transComm.h
+++ b/source/libs/transport/inc/transComm.h
@@ -123,9 +123,9 @@ typedef struct {
 } SRpcReqContext;
 
 typedef struct {
-  SRpcInfo* pRpc;     // associated SRpcInfo
-  SEpSet    epSet;    // ip list provided by app
-  void*     ahandle;  // handle provided by app
+  SRpcInfo* pTransInst;  // associated SRpcInfo
+  SEpSet    epSet;       // ip list provided by app
+  void*     ahandle;     // handle provided by app
   // struct SRpcConn* pConn;     // pConn allocated
   tmsg_t   msgType;  // message type
   uint8_t* pCont;    // content provided by app
diff --git a/source/libs/transport/src/transCli.c b/source/libs/transport/src/transCli.c
index bfadfe56eff19e4738d53a9f1209bac421d16095..e5b80d84196fdb5b8d9a1b0bcf823c170ac12621 100644
--- a/source/libs/transport/src/transCli.c
+++ b/source/libs/transport/src/transCli.c
@@ -30,6 +30,7 @@ typedef struct SCliConn {
   char         spi;
   char         secured;
   uint64_t     expireTime;
+  int8_t       notifyCount;  // timers already notify to client
 } SCliConn;
 
 typedef struct SCliMsg {
@@ -72,8 +73,6 @@ static void      addConnToPool(void* pool, char* ip, uint32_t port, SCliConn* co
 
 // register timer in each thread to clear expire conn
 static void clientTimeoutCb(uv_timer_t* handle);
-// process data read from server, auth/decompress etc later
-static void clientHandleResp(SCliConn* conn);
 // check whether already read complete packet from server
 static bool clientReadComplete(SConnBuffer* pBuf);
 // alloc buf for read
@@ -88,10 +87,15 @@ static void clientAsyncCb(uv_async_t* handle);
 static void clientDestroy(uv_handle_t* handle);
 static void clientConnDestroy(SCliConn* pConn, bool clear /*clear tcp handle or not*/);
 
-static void clientMsgDestroy(SCliMsg* pMsg);
+// process data read from server, auth/decompress etc later
+static void clientHandleResp(SCliConn* conn);
+// handle except about conn
+static void clientHandleExcept(SCliConn* conn);
 // handle req from app
 static void clientHandleReq(SCliMsg* pMsg, SCliThrdObj* pThrd);
 
+static void clientMsgDestroy(SCliMsg* pMsg);
+static void destroyTransConnCtx(STransConnCtx* ctx);
 // thread obj
 static SCliThrdObj* createThrdObj();
 static void         destroyThrdObj(SCliThrdObj* pThrd);
@@ -100,22 +104,38 @@ static void* clientThread(void* arg);
 
 static void clientHandleResp(SCliConn* conn) {
   STransConnCtx* pCtx = ((SCliMsg*)conn->data)->ctx;
-  SRpcInfo*      pRpc = pCtx->pRpc;
+  SRpcInfo*      pRpc = pCtx->pTransInst;
   SRpcMsg        rpcMsg;
 
   rpcMsg.pCont = conn->readBuf.buf;
   rpcMsg.contLen = conn->readBuf.len;
   rpcMsg.ahandle = pCtx->ahandle;
   (pRpc->cfp)(NULL, &rpcMsg, NULL);
+  conn->notifyCount += 1;
 
   SCliThrdObj* pThrd = conn->hostThrd;
   addConnToPool(pThrd->pool, pCtx->ip, pCtx->port, conn);
+
+  // start thread's timer of conn pool if not active
   if (!uv_is_active((uv_handle_t*)pThrd->pTimer) && pRpc->idleTime > 0) {
     uv_timer_start((uv_timer_t*)pThrd->pTimer, clientTimeoutCb, CONN_PERSIST_TIME(pRpc->idleTime) / 2, 0);
   }
-  free(pCtx->ip);
-  free(pCtx);
-  // impl
+  destroyTransConnCtx(pCtx);
+}
+static void clientHandleExcept(SCliConn* pConn) {
+  SCliMsg* pMsg = pConn->data;
+
+  STransConnCtx* pCtx = pMsg->ctx;
+  SRpcInfo*      pRpc = pCtx->pTransInst;
+
+  SRpcMsg rpcMsg;
+  rpcMsg.ahandle = pCtx->ahandle;
+  // SRpcInfo* pRpc = pMsg->ctx->pRpc;
+  (pRpc->cfp)(NULL, &rpcMsg, NULL);
+
+  pConn->notifyCount += 1;
+  destroyTransConnCtx(pCtx);
+  clientConnDestroy(pConn, true);
 }
 
 static void clientTimeoutCb(uv_timer_t* handle) {
@@ -191,6 +211,7 @@ static void addConnToPool(void* pool, char* ip, uint32_t port, SCliConn* conn) {
   SRpcInfo* pRpc = ((SCliThrdObj*)conn->hostThrd)->pTransInst;
   conn->expireTime = taosGetTimestampMs() + CONN_PERSIST_TIME(pRpc->idleTime);
   SConnList* plist = taosHashGet((SHashObj*)pool, key, strlen(key));
+  conn->notifyCount = 0;
   // list already create before
   assert(plist != NULL);
   QUEUE_PUSH(&plist->conn, &conn->conn);
@@ -246,19 +267,21 @@ static void clientReadCb(uv_stream_t* handle, ssize_t nread, const uv_buf_t* buf
   if (nread > 0) {
     pBuf->len += nread;
     if (clientReadComplete(pBuf)) {
-      tDebug("alread read complete");
+      tDebug("conn read complete");
       clientHandleResp(conn);
     } else {
-      tDebug("read half packet, continue to read");
+      tDebug("conn read half packet, continue to read");
     }
     return;
   }
   assert(nread <= 0);
   if (nread == 0) {
+    tError("conn closed");
     return;
   }
-  if (nread != UV_EOF) {
-    tDebug("read error %s", uv_err_name(nread));
+  if (nread < 0) {
+    tError("conn read error: %s", uv_err_name(nread));
+    clientHandleExcept(conn);
   }
   // tDebug("Read error %s\n", uv_err_name(nread));
   // uv_close((uv_handle_t*)handle, clientDestroy);
@@ -282,19 +305,20 @@ static void clientDestroy(uv_handle_t* handle) {
 
 static void clientWriteCb(uv_write_t* req, int status) {
   SCliConn* pConn = req->data;
+
   if (status == 0) {
-    tDebug("data already was written on stream");
+    tDebug("conn data already was written out");
   } else {
     tError("failed to write: %s", uv_err_name(status));
-    clientConnDestroy(pConn, true);
+    clientHandleExcept(pConn);
     return;
   }
   SCliThrdObj* pThrd = pConn->hostThrd;
-  if (pConn->stream == NULL) {
-    pConn->stream = (uv_stream_t*)malloc(sizeof(uv_tcp_t));
-    uv_tcp_init(pThrd->loop, (uv_tcp_t*)pConn->stream);
-    pConn->stream->data = pConn;
-  }
+  // if (pConn->stream == NULL) {
+  //  pConn->stream = (uv_stream_t*)malloc(sizeof(uv_tcp_t));
+  //  uv_tcp_init(pThrd->loop, (uv_tcp_t*)pConn->stream);
+  //  pConn->stream->data = pConn;
+  //}
   uv_read_start((uv_stream_t*)pConn->stream, clientAllocReadBufferCb, clientReadCb);
   // impl later
 }
@@ -316,23 +340,10 @@ static void clientWrite(SCliConn* pConn) {
 static void clientConnCb(uv_connect_t* req, int status) {
   // impl later
   SCliConn* pConn = req->data;
-  SCliMsg*  pMsg = pConn->data;
-
-  STransConnCtx* pCtx = pMsg->ctx;
-  SRpcInfo*      pRpc = pCtx->pRpc;
-
   if (status != 0) {
     // tError("failed to connect server(%s, %d), errmsg: %s", pCtx->ip, pCtx->port, uv_strerror(status));
     tError("failed to connect server,  errmsg: %s", uv_strerror(status));
-    // call user fp later
-    SRpcMsg rpcMsg;
-    rpcMsg.ahandle = pCtx->ahandle;
-    // SRpcInfo* pRpc = pMsg->ctx->pRpc;
-    (pRpc->cfp)(NULL, &rpcMsg, NULL);
-
-    clientConnDestroy(pConn, true);
-    // uv_close((uv_handle_t*)req->handle, clientDestroy);
-    return;
+    clientHandleExcept(pConn);
   }
 
   assert(pConn->stream == req->handle);
@@ -462,6 +473,13 @@ static void destroyThrdObj(SCliThrdObj* pThrd) {
   free(pThrd->loop);
   free(pThrd);
 }
+
+static void destroyTransConnCtx(STransConnCtx* ctx) {
+  if (ctx != NULL) {
+    free(ctx->ip);
+  }
+  free(ctx);
+}
 //
 void taosCloseClient(void* arg) {
   // impl later
@@ -472,7 +490,6 @@ void taosCloseClient(void* arg) {
   free(cli->pThreadObj);
   free(cli);
 }
-
 void rpcSendRequest(void* shandle, const SEpSet* pEpSet, SRpcMsg* pMsg, int64_t* pRid) {
   // impl later
   char*    ip = (char*)(pEpSet->fqdn[pEpSet->inUse]);
@@ -487,7 +504,7 @@ void rpcSendRequest(void* shandle, const SEpSet* pEpSet, SRpcMsg* pMsg, int64_t*
 
   STransConnCtx* pCtx = calloc(1, sizeof(STransConnCtx));
 
-  pCtx->pRpc = (SRpcInfo*)shandle;
+  pCtx->pTransInst = (SRpcInfo*)shandle;
   pCtx->ahandle = pMsg->ahandle;
   pCtx->msgType = pMsg->msgType;
   pCtx->ip = strdup(ip);
diff --git a/source/libs/transport/src/transSrv.c b/source/libs/transport/src/transSrv.c
index b519a35f2491f4041263de8a03aaa1d7f976a71b..3b7b4d6fea0c6209aad6580e28a8f7eb57c65cff 100644
--- a/source/libs/transport/src/transSrv.c
+++ b/source/libs/transport/src/transSrv.c
@@ -16,6 +16,7 @@
 #ifdef USE_UV
 
 #include "transComm.h"
+
 typedef struct SConn {
   uv_tcp_t*   pTcp;
   uv_write_t* pWriter;
@@ -226,7 +227,7 @@ static void uvHandleActivityTimeout(uv_timer_t* handle) {
   tDebug("%p timeout since no activity", conn);
 }
 
-static void uvProcessData(SConn* pConn) {
+static void uvHandleReq(SConn* pConn) {
   SRecvInfo    info;
   SRecvInfo*   p = &info;
   SConnBuffer* pBuf = &pConn->connBuf;
@@ -283,20 +284,23 @@ void uvOnReadCb(uv_stream_t* cli, ssize_t nread, const uv_buf_t* buf) {
   SConnBuffer* pBuf = &conn->connBuf;
   if (nread > 0) {
     pBuf->len += nread;
-    tDebug("on read %p, total read: %d, current read: %d", cli, pBuf->len, (int)nread);
+    tDebug("conn %p read summroy, total read: %d, current read: %d", conn, pBuf->len, (int)nread);
     if (readComplete(pBuf)) {
-      tDebug("alread read complete packet");
-      uvProcessData(conn);
+      tDebug("conn %p alread read complete packet", conn);
+      uvHandleReq(conn);
     } else {
-      tDebug("read half packet, continue to read");
+      tDebug("conn %p read partial packet, continue to read", conn);
     }
     return;
   }
   if (nread == 0) {
+    tDebug("conn %p except read", conn);
+    // destroyConn(conn, true);
     return;
   }
   if (nread != UV_EOF) {
-    tDebug("read error %s", uv_err_name(nread));
+    tDebug("conn %p read error: %s", conn, uv_err_name(nread));
+    destroyConn(conn, true);
   }
 }
 void uvAllocConnBufferCb(uv_handle_t* handle, size_t suggested_size, uv_buf_t* buf) {
@@ -306,7 +310,8 @@ void uvAllocConnBufferCb(uv_handle_t* handle, size_t suggested_size, uv_buf_t* b
 
 void uvOnTimeoutCb(uv_timer_t* handle) {
   // opt
-  tDebug("time out");
+  SConn* pConn = handle->data;
+  tDebug("conn %p time out", pConn);
 }
 
 void uvOnWriteCb(uv_write_t* req, int status) {
@@ -317,9 +322,9 @@ void uvOnWriteCb(uv_write_t* req, int status) {
   memset(buf->buf, 0, buf->cap);
   buf->left = -1;
   if (status == 0) {
-    tDebug("data already was written on stream");
+    tDebug("conn %p data already was written on stream", conn);
   } else {
-    tDebug("failed to write data, %s", uv_err_name(status));
+    tDebug("conn %p failed to write data, %s", conn, uv_err_name(status));
     destroyConn(conn, true);
   }
   // opt
@@ -334,7 +339,7 @@ static void uvOnPipeWriteCb(uv_write_t* req, int status) {
 
 static void uvPrepareSendData(SConn* conn, uv_buf_t* wb) {
   // impl later;
-  tDebug("prepare to send back");
+  tDebug("conn %p prepare to send resp", conn);
   SRpcMsg* pMsg = &conn->sendMsg;
   if (pMsg->pCont == 0) {
     pMsg->pCont = (void*)rpcMallocCont(0);
@@ -448,7 +453,7 @@ void uvOnConnectionCb(uv_stream_t* q, ssize_t nread, const uv_buf_t* buf) {
   if (uv_accept(q, (uv_stream_t*)(pConn->pTcp)) == 0) {
     uv_os_fd_t fd;
     uv_fileno((const uv_handle_t*)pConn->pTcp, &fd);
-    tDebug("new connection created: %d", fd);
+    tDebug("conn %p created, fd: %d", pConn, fd);
     uv_read_start((uv_stream_t*)(pConn->pTcp), uvAllocReadBufferCb, uvOnReadCb);
   } else {
     tDebug("failed to create new connection");
@@ -517,17 +522,13 @@ static SConn* createConn() {
   SConn* pConn = (SConn*)calloc(1, sizeof(SConn));
   return pConn;
 }
-static void connCloseCb(uv_handle_t* handle) {
-  // impl later
-  //
-}
+
 static void destroyConn(SConn* conn, bool clear) {
   if (conn == NULL) {
     return;
   }
   if (clear) {
-    uv_handle_t handle = *((uv_handle_t*)conn->pTcp);
-    uv_close(&handle, NULL);
+    uv_close((uv_handle_t*)conn->pTcp, NULL);
   }
   uv_timer_stop(conn->pTimer);
   free(conn->pTimer);
@@ -646,6 +647,7 @@ void rpcSendResponse(const SRpcMsg* pMsg) {
   pthread_mutex_lock(&pThrd->connMtx);
   QUEUE_PUSH(&pThrd->conn, &pConn->queue);
   pthread_mutex_unlock(&pThrd->connMtx);
+  tDebug("conn %p start to send resp", pConn);
 
   uv_async_send(pConn->pWorkerAsync);
 }