diff --git a/include/libs/transport/trpc.h b/include/libs/transport/trpc.h
index d8dcf72bed..aae0c6bd22 100644
--- a/include/libs/transport/trpc.h
+++ b/include/libs/transport/trpc.h
@@ -70,12 +70,19 @@ typedef struct SRpcInit {
   // call back to retrieve the client auth info, for server app only
   int (*afp)(void *parent, char *tableId, char *spi, char *encrypt, char *secret, char *ckey);
 
-  // to support Send messages multiple times on a link
-  void *(*mfp)(void *parent, tmsg_t msgType);
-
   void *parent;
 } SRpcInit;
 
+typedef struct {
+  void *  val;
+  int32_t len;
+  void (*free)(void *arg);
+} SRpcCtxVal;
+
+typedef struct {
+  SHashObj *args;
+} SRpcCtx;
+
 int32_t rpcInit();
 void    rpcCleanup();
 void *  rpcOpen(const SRpcInit *pRpc);
@@ -84,16 +91,17 @@ void *  rpcMallocCont(int contLen);
 void    rpcFreeCont(void *pCont);
 void *  rpcReallocCont(void *ptr, int contLen);
 void    rpcSendRequest(void *thandle, const SEpSet *pEpSet, SRpcMsg *pMsg, int64_t *rid);
-void    rpcSendResponse(const SRpcMsg *pMsg);
-void    rpcSendRedirectRsp(void *pConn, const SEpSet *pEpSet);
-int     rpcGetConnInfo(void *thandle, SRpcConnInfo *pInfo);
-void    rpcSendRecv(void *shandle, SEpSet *pEpSet, SRpcMsg *pReq, SRpcMsg *pRsp);
-int     rpcReportProgress(void *pConn, char *pCont, int contLen);
-void    rpcCancelRequest(int64_t rid);
+void    rpcSendRequestWithCtx(void *thandle, const SEpSet *pEpSet, SRpcMsg *pMsg, int64_t *rid, SRpcCtx *ctx);
 
+void rpcSendResponse(const SRpcMsg *pMsg);
+void rpcSendRedirectRsp(void *pConn, const SEpSet *pEpSet);
+int  rpcGetConnInfo(void *thandle, SRpcConnInfo *pInfo);
+void rpcSendRecv(void *shandle, SEpSet *pEpSet, SRpcMsg *pReq, SRpcMsg *pRsp);
+int  rpcReportProgress(void *pConn, char *pCont, int contLen);
+void rpcCancelRequest(int64_t rid);
+void rpcRegisterBrokenLinkArg(SRpcMsg *msg);
 // just release client conn to rpc instance, no close sock
-void rpcReleaseHandle(void *handle, int8_t type);
-
+void rpcReleaseHandle(void *handle, int8_t type);  //
 void rpcRefHandle(void *handle, int8_t type);
 void rpcUnrefHandle(void *handle, int8_t type);
 
diff --git a/source/libs/transport/inc/transComm.h b/source/libs/transport/inc/transComm.h
index a60531a429..a939bbd644 100644
--- a/source/libs/transport/inc/transComm.h
+++ b/source/libs/transport/inc/transComm.h
@@ -14,6 +14,10 @@
  */
 #ifdef USE_UV
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 #include <uv.h>
 #include "lz4.h"
 #include "os.h"
@@ -121,24 +125,21 @@ typedef struct {
 } SRpcReqContext;
 
 typedef SRpcMsg      STransMsg;
+typedef SRpcCtx      STransCtx;
+typedef SRpcCtxVal   STransCtxVal;
 typedef SRpcInfo     STrans;
 typedef SRpcConnInfo STransHandleInfo;
 
 typedef struct {
-  SEpSet   epSet;    // ip list provided by app
-  void*    ahandle;  // handle provided by app
-  tmsg_t   msgType;  // message type
-  uint8_t* pCont;    // content provided by app
-  int32_t  contLen;  // content length
-  // int32_t  code;     // error code
-  // int16_t  numOfTry;  // number of try for different servers
-  // int8_t   oldInUse;  // server EP inUse passed by app
-  // int8_t   redirect;  // flag to indicate redirect
+  SEpSet  epSet;     // ip list provided by app
+  void*   ahandle;   // handle provided by app
+  tmsg_t  msgType;   // message type
   int8_t  connType;  // connection type cli/srv
   int64_t rid;       // refId returned by taosAddRef
 
-  STransMsg* pRsp;  // for synchronous API
-  tsem_t*    pSem;  // for synchronous API
+  STransCtx  appCtx;  //
+  STransMsg* pRsp;    // for synchronous API
+  tsem_t*    pSem;    // for synchronous API
 
   int      hThrdIdx;
   char*    ip;
@@ -181,7 +182,7 @@ typedef struct {
 #pragma pack(pop)
 
 typedef enum { Normal, Quit, Release } STransMsgType;
-typedef enum { ConnNormal, ConnAcquire, ConnRelease } ConnStatus;
+typedef enum { ConnNormal, ConnAcquire, ConnRelease, ConnBroken } ConnStatus;
 
 #define container_of(ptr, type, member) ((type*)((char*)(ptr)-offsetof(type, member)))
 #define RPC_RESERVE_SIZE (sizeof(STranConnCtx))
@@ -259,7 +260,7 @@ void transUnrefCliHandle(void* handle);
 void transReleaseCliHandle(void* handle);
 void transReleaseSrvHandle(void* handle);
 
-void transSendRequest(void* shandle, const char* ip, uint32_t port, STransMsg* pMsg);
+void transSendRequest(void* shandle, const char* ip, uint32_t port, STransMsg* pMsg, STransCtx* pCtx);
 void transSendRecv(void* shandle, const char* ip, uint32_t port, STransMsg* pMsg, STransMsg* pRsp);
 void transSendResponse(const STransMsg* pMsg);
 int  transGetConnInfo(void* thandle, STransHandleInfo* pInfo);
@@ -270,4 +271,14 @@ void* transInitClient(uint32_t ip, uint32_t port, char* label, int numOfThreads,
 void transCloseClient(void* arg);
 void transCloseServer(void* arg);
 
+void  transCtxInit(STransCtx* ctx);
+void  transCtxDestroy(STransCtx* ctx);
+void  transCtxClear(STransCtx* ctx);
+void  transCtxMerge(STransCtx* dst, STransCtx* src);
+void* transCtxDumpVal(STransCtx* ctx, int32_t key);
+
+#ifdef __cplusplus
+}
+#endif
+
 #endif
diff --git a/source/libs/transport/inc/transportInt.h b/source/libs/transport/inc/transportInt.h
index e739380467..1395408960 100644
--- a/source/libs/transport/inc/transportInt.h
+++ b/source/libs/transport/inc/transportInt.h
@@ -63,9 +63,6 @@ typedef struct {
 
   void (*cfp)(void* parent, SRpcMsg*, SEpSet*);
   int (*afp)(void* parent, char* user, char* spi, char* encrypt, char* secret, char* ckey);
-  bool (*pfp)(void* parent, tmsg_t msgType);
-  void* (*mfp)(void* parent, tmsg_t msgType);
-  bool (*efp)(void* parent, tmsg_t msgType);
 
   int32_t         refCount;
   void*           parent;
diff --git a/source/libs/transport/src/.transCli.c.swn b/source/libs/transport/src/.transCli.c.swn
new file mode 100644
index 0000000000..583fbc9f74
Binary files /dev/null and b/source/libs/transport/src/.transCli.c.swn differ
diff --git a/source/libs/transport/src/trans.c b/source/libs/transport/src/trans.c
index a688e9981e..ded53ab4ea 100644
--- a/source/libs/transport/src/trans.c
+++ b/source/libs/transport/src/trans.c
@@ -39,7 +39,6 @@ void* rpcOpen(const SRpcInit* pInit) {
   // register callback handle
   pRpc->cfp = pInit->cfp;
   pRpc->afp = pInit->afp;
-  pRpc->mfp = pInit->mfp;
 
   if (pInit->connType == TAOS_CONN_SERVER) {
     pRpc->numOfThreads = pInit->numOfThreads > TSDB_MAX_RPC_THREADS ? TSDB_MAX_RPC_THREADS : pInit->numOfThreads;
@@ -119,7 +118,12 @@ void rpcCancelRequest(int64_t rid) { return; }
 void rpcSendRequest(void* shandle, const SEpSet* pEpSet, SRpcMsg* pMsg, int64_t* pRid) {
   char*    ip = (char*)(pEpSet->eps[pEpSet->inUse].fqdn);
   uint32_t port = pEpSet->eps[pEpSet->inUse].port;
-  transSendRequest(shandle, ip, port, pMsg);
+  transSendRequest(shandle, ip, port, pMsg, NULL);
+}
+void rpcSendRequestWithCtx(void* shandle, const SEpSet* pEpSet, SRpcMsg* pMsg, int64_t* pRid, SRpcCtx* pCtx) {
+  char*    ip = (char*)(pEpSet->eps[pEpSet->inUse].fqdn);
+  uint32_t port = pEpSet->eps[pEpSet->inUse].port;
+  transSendRequest(shandle, ip, port, pMsg, pCtx);
 }
 void rpcSendRecv(void* shandle, SEpSet* pEpSet, SRpcMsg* pMsg, SRpcMsg* pRsp) {
   char*    ip = (char*)(pEpSet->eps[pEpSet->inUse].fqdn);
@@ -140,6 +144,10 @@ void rpcUnrefHandle(void* handle, int8_t type) {
   (*taosUnRefHandle[type])(handle);
 }
 
+void rpcRegisterBrokenLinkArg(SRpcMsg* msg) {
+  //
+  rpcSendResponse(msg);
+}
 void rpcReleaseHandle(void* handle, int8_t type) {
   assert(type == TAOS_CONN_SERVER || type == TAOS_CONN_CLIENT);
   (*transReleaseHandle[type])(handle);
diff --git a/source/libs/transport/src/transCli.c b/source/libs/transport/src/transCli.c
index 7100c34845..18a0611b75 100644
--- a/source/libs/transport/src/transCli.c
+++ b/source/libs/transport/src/transCli.c
@@ -30,6 +30,7 @@ typedef struct SCliConn {
   uint64_t     expireTime;
   int          hThrdIdx;
   bool         broken;  // link broken or not
+  STransCtx    ctx;
 
   ConnStatus status;   //
   int        release;  // 1: release
@@ -207,7 +208,7 @@ void cliHandleResp(SCliConn* conn) {
 
   STransConnCtx* pCtx = pMsg ? pMsg->ctx : NULL;
   if (pMsg == NULL && !CONN_NO_PERSIST_BY_APP(conn)) {
-    transMsg.ahandle = pTransInst->mfp ? (*pTransInst->mfp)(pTransInst->parent, transMsg.msgType) : NULL;
+    transMsg.ahandle = transCtxDumpVal(&conn->ctx, transMsg.msgType);
   } else {
     transMsg.ahandle = pCtx ? pCtx->ahandle : NULL;
   }
@@ -283,7 +284,7 @@ void cliHandleExcept(SCliConn* pConn) {
     transMsg.ahandle = NULL;
 
     if (pMsg == NULL && !CONN_NO_PERSIST_BY_APP(pConn)) {
-      transMsg.ahandle = pTransInst->mfp ? (*pTransInst->mfp)(pTransInst->parent, transMsg.msgType) : NULL;
+      transMsg.ahandle = transCtxDumpVal(&pConn->ctx, transMsg.msgType);
     } else {
       transMsg.ahandle = pCtx ? pCtx->ahandle : NULL;
     }
@@ -374,6 +375,7 @@ static SCliConn* getConnFromPool(void* pool, char* ip, uint32_t port) {
 static void addConnToPool(void* pool, SCliConn* conn) {
   char key[128] = {0};
 
+  transCtxDestroy(&conn->ctx);
   tstrncpy(key, conn->ip, strlen(conn->ip));
   tstrncpy(key + strlen(key), (char*)(&conn->port), sizeof(conn->port));
   tTrace("cli conn %p added to conn pool, read buf cap: %d", conn, conn->readBuf.cap);
@@ -436,7 +438,6 @@ static SCliConn* cliCreateConn(SCliThrdObj* pThrd) {
   conn->writeReq.data = conn;
   conn->connReq.data = conn;
   conn->cliMsgs = taosArrayInit(2, sizeof(void*));
-
   QUEUE_INIT(&conn->conn);
   conn->hostThrd = pThrd;
   conn->status = ConnNormal;
@@ -446,6 +447,7 @@ static SCliConn* cliCreateConn(SCliThrdObj* pThrd) {
 }
 static void cliDestroyConn(SCliConn* conn, bool clear) {
   tTrace("%s cli conn %p remove from conn pool", CONN_GET_INST_LABEL(conn), conn);
+
   QUEUE_REMOVE(&conn->conn);
   if (clear) {
     uv_close((uv_handle_t*)conn->stream, cliDestroy);
@@ -455,6 +457,7 @@ static void cliDestroy(uv_handle_t* handle) {
   SCliConn* conn = handle->data;
   free(conn->ip);
   free(conn->stream);
+  transCtxDestroy(&conn->ctx);
   taosArrayDestroy(conn->cliMsgs);
   tTrace("%s cli conn %p destroy successfully", CONN_GET_INST_LABEL(conn), conn);
   free(conn);
@@ -630,10 +633,12 @@ void cliHandleReq(SCliMsg* pMsg, SCliThrdObj* pThrd) {
   if (conn != NULL) {
     conn->hThrdIdx = pCtx->hThrdIdx;
 
+    transCtxMerge(&conn->ctx, &pCtx->appCtx);
     if (taosArrayGetSize(conn->cliMsgs) > 0) {
       taosArrayPush(conn->cliMsgs, &pMsg);
       return;
     }
+
     taosArrayPush(conn->cliMsgs, &pMsg);
     transDestroyBuffer(&conn->readBuf);
     cliSend(conn);
@@ -825,7 +830,7 @@ void transReleaseCliHandle(void* handle) {
   transSendAsync(thrd->asyncPool, &cmsg->q);
 }
 
-void transSendRequest(void* shandle, const char* ip, uint32_t port, STransMsg* pMsg) {
+void transSendRequest(void* shandle, const char* ip, uint32_t port, STransMsg* pMsg, STransCtx* ctx) {
   STrans* pTransInst = (STrans*)shandle;
   int     index = CONN_HOST_THREAD_INDEX((SCliConn*)pMsg->handle);
   if (index == -1) {
@@ -835,13 +840,14 @@ void transSendRequest(void* shandle, const char* ip, uint32_t port, STransMsg* p
   if (transCompressMsg(pMsg->pCont, pMsg->contLen, &flen)) {
     // imp later
   }
-  tDebug("send request at thread:%d %p", index, pMsg);
+  tDebug("send request at thread:%d %p, dst: %s:%d", index, pMsg, ip, port);
   STransConnCtx* pCtx = calloc(1, sizeof(STransConnCtx));
   pCtx->ahandle = pMsg->ahandle;
   pCtx->msgType = pMsg->msgType;
   pCtx->ip = strdup(ip);
   pCtx->port = port;
   pCtx->hThrdIdx = index;
+  pCtx->appCtx = *ctx;
 
   assert(pTransInst->connType == TAOS_CONN_CLIENT);
   // atomic or not
@@ -855,6 +861,7 @@ void transSendRequest(void* shandle, const char* ip, uint32_t port, STransMsg* p
   SCliThrdObj* thrd = ((SCliObj*)pTransInst->tcphandle)->pThreadObj[index];
   transSendAsync(thrd->asyncPool, &(cliMsg->q));
 }
+
 void transSendRecv(void* shandle, const char* ip, uint32_t port, STransMsg* pReq, STransMsg* pRsp) {
   STrans* pTransInst = (STrans*)shandle;
   int     index = CONN_HOST_THREAD_INDEX(pReq->handle);
diff --git a/source/libs/transport/src/transComm.c b/source/libs/transport/src/transComm.c
index 7123593a33..2c90efc3aa 100644
--- a/source/libs/transport/src/transComm.c
+++ b/source/libs/transport/src/transComm.c
@@ -155,9 +155,9 @@ bool transReadComplete(SConnBuffer* connBuf) {
   }
   return false;
 }
-int transPackMsg(STransMsgHead* msgHead, bool sercured, bool auth) {return 0;}
+int transPackMsg(STransMsgHead* msgHead, bool sercured, bool auth) { return 0; }
 
-int transUnpackMsg(STransMsgHead* msgHead) {return 0;}
+int transUnpackMsg(STransMsgHead* msgHead) { return 0; }
 int transDestroyBuffer(SConnBuffer* buf) {
   if (buf->cap > 0) {
     tfree(buf->buf);
@@ -224,4 +224,56 @@ int transSendAsync(SAsyncPool* pool, queue* q) {
   return uv_async_send(async);
 }
 
+void transCtxInit(STransCtx* ctx) {
+  // init transCtx
+  ctx->args = taosHashInit(2, taosGetDefaultHashFunction(TSDB_DATA_TYPE_UINT), true, HASH_NO_LOCK);
+}
+void transCtxDestroy(STransCtx* ctx) {
+  if (ctx->args == NULL) {
+    return;
+  }
+
+  STransCtxVal* iter = taosHashIterate(ctx->args, NULL);
+  while (iter) {
+    iter->free(iter->val);
+    iter = taosHashIterate(ctx->args, iter);
+  }
+  taosHashCleanup(ctx->args);
+}
+
+void transCtxMerge(STransCtx* dst, STransCtx* src) {
+  if (dst->args == NULL) {
+    dst->args = src->args;
+    src->args = NULL;
+    return;
+  }
+  void*  key = NULL;
+  size_t klen = 0;
+  void*  iter = taosHashIterate(src->args, NULL);
+  while (iter) {
+    STransCtxVal* sVal = (STransCtxVal*)iter;
+    key = taosHashGetKey(sVal, &klen);
+
+    STransCtxVal* dVal = taosHashGet(dst->args, key, klen);
+    if (dVal) {
+      dVal->free(dVal->val);
+    }
+    taosHashPut(dst->args, key, klen, sVal, sizeof(*sVal));
+    iter = taosHashIterate(src->args, iter);
+  }
+  taosHashCleanup(src->args);
+}
+void* transCtxDumpVal(STransCtx* ctx, int32_t key) {
+  if (ctx->args == NULL) {
+    return NULL;
+  }
+  STransCtxVal* cVal = taosHashGet(ctx->args, (const void*)&key, sizeof(key));
+  if (cVal == NULL) {
+    return NULL;
+  }
+  char* ret = calloc(1, cVal->len);
+  memcpy(ret, (char*)cVal->val, cVal->len);
+  return (void*)ret;
+}
+
 #endif
diff --git a/source/libs/transport/src/transSrv.c b/source/libs/transport/src/transSrv.c
index 321a3489b7..6be664233b 100644
--- a/source/libs/transport/src/transSrv.c
+++ b/source/libs/transport/src/transSrv.c
@@ -403,16 +403,16 @@ static void uvStartSendResp(SSrvMsg* smsg) {
   return;
 }
 
-static void uvNotifyLinkBrokenToApp(SSrvConn* conn) {
-  STrans* pTransInst = conn->pTransInst;
-  if (pTransInst->efp != NULL && (*pTransInst->efp)(NULL, conn->inType) && T_REF_VAL_GET(conn) >= 2) {
-    STransMsg transMsg = {0};
-    transMsg.msgType = conn->inType;
-    transMsg.code = TSDB_CODE_RPC_NETWORK_UNAVAIL;
-    // transRefSrvHandle(conn);
-    (*pTransInst->cfp)(pTransInst->parent, &transMsg, 0);
-  }
-}
+// static void uvNotifyLinkBrokenToApp(SSrvConn* conn) {
+//  STrans* pTransInst = conn->pTransInst;
+//  if (pTransInst->efp != NULL && (*pTransInst->efp)(NULL, conn->inType) && T_REF_VAL_GET(conn) >= 2) {
+//    STransMsg transMsg = {0};
+//    transMsg.msgType = conn->inType;
+//    transMsg.code = TSDB_CODE_RPC_NETWORK_UNAVAIL;
+//    // transRefSrvHandle(conn);
+//    (*pTransInst->cfp)(pTransInst->parent, &transMsg, 0);
+//  }
+//}
 static void destroySmsg(SSrvMsg* smsg) {
   if (smsg == NULL) {
     return;
diff --git a/source/libs/transport/test/transUT.cc b/source/libs/transport/test/transUT.cc
index 31015359f4..deccd633d8 100644
--- a/source/libs/transport/test/transUT.cc
+++ b/source/libs/transport/test/transUT.cc
@@ -86,18 +86,8 @@ class Client {
     rpcClose(this->transCli);
     this->transCli = NULL;
   }
-  void SetPersistFP(bool (*pfp)(void *parent, tmsg_t msgType)) {
-    rpcClose(this->transCli);
-    this->transCli = rpcOpen(&rpcInit_);
-  }
   void SetConstructFP(void *(*mfp)(void *parent, tmsg_t msgType)) {
     rpcClose(this->transCli);
-    rpcInit_.mfp = mfp;
-    this->transCli = rpcOpen(&rpcInit_);
-  }
-  void SetPAndMFp(bool (*pfp)(void *parent, tmsg_t msgType), void *(*mfp)(void *parent, tmsg_t msgType)) {
-    rpcClose(this->transCli);
-    rpcInit_.mfp = mfp;
     this->transCli = rpcOpen(&rpcInit_);
   }
 
@@ -156,10 +146,6 @@ class Server {
     rpcClose(this->transSrv);
     this->transSrv = NULL;
   }
-  void SetExceptFp(bool (*efp)(void *parent, tmsg_t msgType)) {
-    this->Stop();
-    this->Start();
-  }
   void SetSrvContinueSend(void (*cfp)(void *parent, SRpcMsg *pMsg, SEpSet *pEpSet)) {
     this->Stop();
     rpcInit_.cfp = cfp;
@@ -252,23 +238,11 @@ class TransObj {
     //
     srv->Stop();
   }
-  void SetCliPersistFp(bool (*pfp)(void *parent, tmsg_t msgType)) {
-    // do nothing
-    cli->SetPersistFP(pfp);
-  }
   void SetCliMFp(void *(*mfp)(void *parent, tmsg_t msgType)) {
     // do nothing
     cli->SetConstructFP(mfp);
   }
-  void SetCliMAndPFp(bool (*pfp)(void *parent, tmsg_t msgType), void *(*mfp)(void *parent, tmsg_t msgType)) {
-    // do nothing
-    cli->SetPAndMFp(pfp, mfp);
-  }
   // call when link broken, and notify query or fetch stop
-  void SetSrvExceptFp(bool (*efp)(void *parent, tmsg_t msgType)) {
-    ////////
-    srv->SetExceptFp(efp);
-  }
   void SetSrvContinueSend(void (*cfp)(void *parent, SRpcMsg *pMsg, SEpSet *pEpSet)) {
     ///////
     srv->SetSrvContinueSend(cfp);
@@ -375,22 +349,15 @@ TEST_F(TransEnv, cliReleaseHandle) {
     req.pCont = rpcMallocCont(10);
     req.contLen = 10;
     tr->cliSendAndRecvNoHandle(&req, &resp);
-    // if (i == 5) {
-    //  std::cout << "stop server" << std::endl;
-    //  tr->StopSrv();
-    //}
-    // if (i >= 6) {
     EXPECT_TRUE(resp.code == 0);
     //}
   }
   //////////////////
 }
 TEST_F(TransEnv, cliReleaseHandleExcept) {
-  // tr->SetCliPersistFp(cliPersistHandle);
-
   SRpcMsg resp = {0};
   for (int i = 0; i < 10; i++) {
-    SRpcMsg req = {.handle = resp.handle};
+    SRpcMsg req = {.handle = resp.handle, .persistHandle = 1};
     req.msgType = 1;
     req.pCont = rpcMallocCont(10);
     req.contLen = 10;
@@ -459,7 +426,7 @@ TEST_F(TransEnv, multiCliPersistHandleExcept) {
   // conn broken
 }
 TEST_F(TransEnv, queryExcept) {
-  tr->SetSrvExceptFp(handleExcept);
+  // tr->SetSrvExceptFp(handleExcept);
 
   // query and conn is broken
 }
diff --git a/source/libs/transport/test/transportTests.cc b/source/libs/transport/test/transportTests.cc
index 53910aa30c..1f8c8e8ff2 100644
--- a/source/libs/transport/test/transportTests.cc
+++ b/source/libs/transport/test/transportTests.cc
@@ -136,4 +136,98 @@ TEST_F(QueueEnv, testIter) {
   assert(result.size() == vals.size());
 }
 
+class TransCtxEnv : public ::testing::Test {
+ protected:
+  virtual void SetUp() {
+    ctx = (STransCtx *)calloc(1, sizeof(STransCtx));
+    transCtxInit(ctx);
+    // TODO
+  }
+  virtual void TearDown() {
+    transCtxDestroy(ctx);
+    // formate
+  }
+  STransCtx *ctx;
+};
+
+TEST_F(TransCtxEnv, mergeTest) {
+  int key = 1;
+  {
+    STransCtx *src = (STransCtx *)calloc(1, sizeof(STransCtx));
+    transCtxInit(src);
+    {
+      STransCtxVal val1 = {.val = NULL, .len = 0, .free = free};
+      val1.val = malloc(12);
+      val1.len = 12;
+
+      taosHashPut(src->args, &key, sizeof(key), &val1, sizeof(val1));
+      key++;
+    }
+    {
+      STransCtxVal val1 = {.val = NULL, .len = 0, .free = free};
+      val1.val = malloc(12);
+      val1.len = 12;
+      taosHashPut(src->args, &key, sizeof(key), &val1, sizeof(val1));
+      key++;
+    }
+    transCtxMerge(ctx, src);
+    free(src);
+  }
+  EXPECT_EQ(2, taosHashGetSize(ctx->args));
+  {
+    STransCtx *src = (STransCtx *)calloc(1, sizeof(STransCtx));
+    transCtxInit(src);
+    {
+      STransCtxVal val1 = {.val = NULL, .len = 0, .free = free};
+      val1.val = malloc(12);
+      val1.len = 12;
+
+      taosHashPut(src->args, &key, sizeof(key), &val1, sizeof(val1));
+      key++;
+    }
+    {
+      STransCtxVal val1 = {.val = NULL, .len = 0, .free = free};
+      val1.val = malloc(12);
+      val1.len = 12;
+      taosHashPut(src->args, &key, sizeof(key), &val1, sizeof(val1));
+      key++;
+    }
+    transCtxMerge(ctx, src);
+    free(src);
+  }
+  std::string val("Hello");
+  EXPECT_EQ(4, taosHashGetSize(ctx->args));
+  {
+    key = 1;
+    STransCtx *src = (STransCtx *)calloc(1, sizeof(STransCtx));
+    transCtxInit(src);
+    {
+      STransCtxVal val1 = {.val = NULL, .len = 0, .free = free};
+      val1.val = calloc(1, 11);
+      memcpy(val1.val, val.c_str(), val.size());
+      val1.len = 11;
+
+      taosHashPut(src->args, &key, sizeof(key), &val1, sizeof(val1));
+      key++;
+    }
+    {
+      STransCtxVal val1 = {.val = NULL, .len = 0, .free = free};
+      val1.val = calloc(1, 11);
+      memcpy(val1.val, val.c_str(), val.size());
+      val1.len = 11;
+      taosHashPut(src->args, &key, sizeof(key), &val1, sizeof(val1));
+      key++;
+    }
+    transCtxMerge(ctx, src);
+    free(src);
+  }
+  EXPECT_EQ(4, taosHashGetSize(ctx->args));
+
+  char *skey = (char *)transCtxDumpVal(ctx, 1);
+  EXPECT_EQ(0, strcmp(skey, val.c_str()));
+  free(skey);
+
+  skey = (char *)transCtxDumpVal(ctx, 2);
+  EXPECT_EQ(0, strcmp(skey, val.c_str()));
+}
 #endif