diff --git a/src/inc/trpc.h b/src/inc/trpc.h
index 748fad0e6292464929421fb941ab1a83f5f3e763..6c5d7fa889b855b91fb47e99e1bf5a80bc88f99e 100644
--- a/src/inc/trpc.h
+++ b/src/inc/trpc.h
@@ -78,12 +78,13 @@ void  rpcClose(void *);
 void *rpcMallocCont(int contLen);
 void  rpcFreeCont(void *pCont);
 void *rpcReallocCont(void *ptr, int contLen);
-void  rpcSendRequest(void *thandle, const SRpcIpSet *pIpSet, const SRpcMsg *pMsg);
+void *rpcSendRequest(void *thandle, const SRpcIpSet *pIpSet, const SRpcMsg *pMsg);
 void  rpcSendResponse(const SRpcMsg *pMsg);
 void  rpcSendRedirectRsp(void *pConn, const SRpcIpSet *pIpSet); 
 int   rpcGetConnInfo(void *thandle, SRpcConnInfo *pInfo);
 void  rpcSendRecv(void *shandle, SRpcIpSet *pIpSet, const SRpcMsg *pReq, SRpcMsg *pRsp);
 int   rpcReportProgress(void *pConn, char *pCont, int contLen);
+void  rpcCanelRequest(void *pContext);
 
 #ifdef __cplusplus
 }
diff --git a/src/rpc/src/rpcMain.c b/src/rpc/src/rpcMain.c
index cf15cc690ab52b9fb538fd4809b26774aed06e75..dcbcae452dac52937bd5a7c3c5b220caabc08b91 100644
--- a/src/rpc/src/rpcMain.c
+++ b/src/rpc/src/rpcMain.c
@@ -73,6 +73,7 @@ typedef struct {
   SRpcInfo *pRpc;       // associated SRpcInfo
   SRpcIpSet ipSet;      // ip list provided by app
   void     *ahandle;    // handle provided by app
+  struct SRpcConn *pConn; // pConn allocated
   char      msgType;    // message type
   uint8_t  *pCont;      // content provided by app
   int32_t   contLen;    // content length
@@ -339,7 +340,7 @@ void *rpcReallocCont(void *ptr, int contLen) {
   return start + sizeof(SRpcReqContext) + sizeof(SRpcHead);
 }
 
-void rpcSendRequest(void *shandle, const SRpcIpSet *pIpSet, const SRpcMsg *pMsg) {
+void *rpcSendRequest(void *shandle, const SRpcIpSet *pIpSet, const SRpcMsg *pMsg) {
   SRpcInfo       *pRpc = (SRpcInfo *)shandle;
   SRpcReqContext *pContext;
 
@@ -367,7 +368,7 @@ void rpcSendRequest(void *shandle, const SRpcIpSet *pIpSet, const SRpcMsg *pMsg)
   
   rpcSendReqToServer(pRpc, pContext);
 
-  return;
+  return pContext;
 }
 
 void rpcSendResponse(const SRpcMsg *pRsp) {
@@ -501,6 +502,19 @@ int rpcReportProgress(void *handle, char *pCont, int contLen) {
   return -1;
 }
 
+/* todo: cancel process may have race condition, pContext may have been released 
+   just before app calls the rpcCancelRequest */
+void rpcCancelRequest(void *handle) {
+  SRpcReqContext *pContext = handle;
+
+  if (pContext->pConn) {
+    tTrace("%s, app trys to cancel request", pContext->pConn->info);
+    rpcCloseConn(pContext->pConn);
+    pContext->pConn = NULL;
+    rpcFreeCont(pContext->pCont);
+  }
+}
+
 static void rpcFreeMsg(void *msg) {
   if ( msg ) {
     char *temp = (char *)msg - sizeof(SRpcReqContext);
@@ -874,6 +888,7 @@ static void rpcReportBrokenLinkToServer(SRpcConn *pConn) {
   SRpcMsg rpcMsg;
   rpcMsg.pCont = pConn->pReqMsg;     // pReqMsg is re-used to store the APP context from server
   rpcMsg.contLen = pConn->reqMsgLen; // reqMsgLen is re-used to store the APP context length
+  rpcMsg.ahandle = pConn->ahandle;
   rpcMsg.handle = pConn;
   rpcMsg.msgType = pConn->inType;
   rpcMsg.code = TSDB_CODE_RPC_NETWORK_UNAVAIL; 
@@ -942,6 +957,7 @@ static void *rpcProcessMsgFromPeer(SRecvInfo *pRecv) {
 static void rpcNotifyClient(SRpcReqContext *pContext, SRpcMsg *pMsg) {
   SRpcInfo       *pRpc = pContext->pRpc;
 
+  pContext->pConn = NULL;
   if (pContext->pRsp) { 
     // for synchronous API
     memcpy(pContext->pSet, &pContext->ipSet, sizeof(SRpcIpSet));
@@ -1110,6 +1126,7 @@ static void rpcSendReqToServer(SRpcInfo *pRpc, SRpcReqContext *pContext) {
     return;
   }
 
+  pContext->pConn = pConn;
   pConn->ahandle = pContext->ahandle;
   rpcLockConn(pConn);