diff --git a/src/common/src/tglobal.c b/src/common/src/tglobal.c
index e588339ca742af86b97898e1dd70e928622302f0..d04033abc911bc0d988d8bcb116e3fd1f0249d52 100644
--- a/src/common/src/tglobal.c
+++ b/src/common/src/tglobal.c
@@ -1183,9 +1183,7 @@ bool taosCheckGlobalCfg() {
     taosGetFqdn(tsLocalFqdn);
   }
 
-  strcpy(tsLocalEp, tsLocalFqdn);
-
-  snprintf(tsLocalEp + strlen(tsLocalEp), sizeof(tsLocalEp), ":%d", tsServerPort);
+  snprintf(tsLocalEp, sizeof(tsLocalEp), "%s:%d", tsLocalFqdn, tsServerPort);
   uPrint("localEp is: %s", tsLocalEp);
 
   if (tsFirst[0] == 0) {
diff --git a/src/rpc/src/rpcMain.c b/src/rpc/src/rpcMain.c
index f62df5677167d50bfe3c39717efa47c69debc487..1a81f32cf24ee01860c2443c694978f6ded2db7d 100644
--- a/src/rpc/src/rpcMain.c
+++ b/src/rpc/src/rpcMain.c
@@ -434,6 +434,7 @@ void rpcSendResponse(const SRpcMsg *pRsp) {
   pConn->rspMsgLen = msgLen;
   if (pMsg->code == TSDB_CODE_RPC_ACTION_IN_PROGRESS) pConn->inTranId--;
 
+  // stop the progress timer
   taosTmrStopA(&pConn->pTimer);
 
   // set the idle timer to monitor the activity
@@ -1021,7 +1022,11 @@ static void rpcProcessIncomingMsg(SRpcConn *pConn, SRpcHead *pHead) {
   if ( rpcIsReq(pHead->msgType) ) {
     rpcMsg.handle = pConn;
     rpcAddRef(pRpc);  // add the refCount for requests
+
+    // start the progress timer to monitor the response from server app
     pConn->pTimer = taosTmrStart(rpcProcessProgressTimer, tsProgressTimer, pConn, pRpc->tmrCtrl);
+ 
+    // notify the server app
     (*(pRpc->cfp))(&rpcMsg, NULL);
   } else {
     // it's a response
diff --git a/src/util/inc/tutil.h b/src/util/inc/tutil.h
index 23d8348cbe5def10d447af4da44aa3fdbe17d183..949e9eb10972657e8bd72e49124c217bdb1679a0 100644
--- a/src/util/inc/tutil.h
+++ b/src/util/inc/tutil.h
@@ -183,6 +183,7 @@ char *taosIpStr(uint32_t ipInt);
 uint32_t ip2uint(const char *const ip_addr);
 
 void taosRemoveDir(char *rootDir);
+int  tmkdir(const char *pathname, mode_t mode); 
 
 #define TAOS_ALLOC_MODE_DEFAULT 0
 #define TAOS_ALLOC_MODE_RANDOM_FAIL 1
diff --git a/src/util/src/tutil.c b/src/util/src/tutil.c
index 2bfef63f846d9cebd929c4cedf2485619194113d..481cf498ca270f812325b88e52bfe874fe923986 100644
--- a/src/util/src/tutil.c
+++ b/src/util/src/tutil.c
@@ -793,3 +793,9 @@ void taosRemoveDir(char *rootDir) {
 
   uPrint("dir:%s is removed", rootDir);
 }
+
+int tmkdir(const char *path, mode_t mode) {
+  int code = mkdir(path, 0755);
+  if (code < 0 && errno == EEXIST) code = 0;
+  return code;
+}
diff --git a/src/wal/src/walMain.c b/src/wal/src/walMain.c
index b05b0db4c94ffa85779bcfd0f73246464f95101f..41669fc691a1d77160145b31c79308fdc5173618 100644
--- a/src/wal/src/walMain.c
+++ b/src/wal/src/walMain.c
@@ -71,14 +71,12 @@ void *walOpen(const char *path, const SWalCfg *pCfg) {
   tstrncpy(pWal->path, path, sizeof(pWal->path));
   pthread_mutex_init(&pWal->mutex, NULL);
 
-  if (access(path, F_OK) != 0) {
-    if (mkdir(path, 0755) != 0) {
-      terrno = TAOS_SYSTEM_ERROR(errno);
-      wError("wal:%s, failed to create directory(%s)", path, strerror(errno));
-      pthread_mutex_destroy(&pWal->mutex);
-      free(pWal);
-      pWal = NULL;
-    }
+  if (tmkdir(path, 0755) != 0) {
+    terrno = TAOS_SYSTEM_ERROR(errno);
+    wError("wal:%s, failed to create directory(%s)", path, strerror(errno));
+    pthread_mutex_destroy(&pWal->mutex);
+    free(pWal);
+    pWal = NULL;
   }
      
   if (pCfg->keep == 1) return pWal;
@@ -86,16 +84,15 @@ void *walOpen(const char *path, const SWalCfg *pCfg) {
   if (walHandleExistingFiles(path) == 0) 
     walRenew(pWal);
 
-  if (pWal->fd <0) {
+  if (pWal && pWal->fd <0) {
     terrno = TAOS_SYSTEM_ERROR(errno);
     wError("wal:%s, failed to open(%s)", path, strerror(errno));
     pthread_mutex_destroy(&pWal->mutex);
     free(pWal);
     pWal = NULL;
-  } else {
-    wTrace("wal:%s, it is open, level:%d", path, pWal->level);
-  }
+  } 
 
+  if (pWal) wTrace("wal:%s, it is open, level:%d", path, pWal->level);
   return pWal;
 }
 
@@ -218,10 +215,13 @@ int walRestore(void *handle, void *pVnode, int (*writeFp)(void *, void *, int))
   if ( pWal->keep == 0) 
     strcpy(opath+slen, "/old");
 
-  // is there old directory?
-  if (access(opath, F_OK)) return 0; 
-
   DIR *dir = opendir(opath);
+  if (dir == NULL && errno == ENOENT) return 0;
+  if (dir == NULL) {
+    terrno = TAOS_SYSTEM_ERROR(errno);
+    return terrno;
+  }
+
   while ((ent = readdir(dir))!= NULL) {
     if ( strncmp(ent->d_name, walPrefix, plen) == 0) {
       index = atol(ent->d_name + plen);
@@ -379,12 +379,10 @@ int walHandleExistingFiles(const char *path) {
       if ( strncmp(ent->d_name, walPrefix, plen) == 0) {
         snprintf(oname, sizeof(oname), "%s/%s", path, ent->d_name);
         snprintf(nname, sizeof(nname), "%s/old/%s", path, ent->d_name);
-        if (access(opath, F_OK) != 0) {
-          if (mkdir(opath, 0755) != 0) {
-            wError("wal:%s, failed to create directory:%s(%s)", oname, opath, strerror(errno));
-            terrno = TAOS_SYSTEM_ERROR(errno);
-            break;
-          } 
+        if (tmkdir(opath, 0755) != 0) {
+          wError("wal:%s, failed to create directory:%s(%s)", oname, opath, strerror(errno));
+          terrno = TAOS_SYSTEM_ERROR(errno);
+          break; 
         }
 
         if (rename(oname, nname) < 0) {
@@ -409,10 +407,14 @@ static int walRemoveWalFiles(const char *path) {
   char   name[TSDB_FILENAME_LEN * 3];
  
   terrno = 0;
-  if (access(path, F_OK) != 0) return 0;
 
   struct dirent *ent;
   DIR   *dir = opendir(path);
+  if (dir == NULL && errno == ENOENT) return 0;
+  if (dir == NULL) {
+    terrno = TAOS_SYSTEM_ERROR(errno);
+    return terrno;
+  }  
 
   while ((ent = readdir(dir))!= NULL) {
     if ( strncmp(ent->d_name, walPrefix, plen) == 0) {