diff --git a/.gitignore b/.gitignore
index bb9a70e9b284194c308ff5a6d57bd3edfdce6799..77c52b2ee2d00da281cc6ddec32d4003c9b90c2b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -64,4 +64,5 @@ CMakeError.log
 /out/isenseconfig/WSL-Clang-Debug
 /out/isenseconfig/WSL-GCC-Debug
 /test/cfg
-/src/.vs
+/src/.vs
+*.o
diff --git a/src/client/src/tscSub.c b/src/client/src/tscSub.c
index 9baf49ff211667e8fd83b5494824aa8ba793aba0..1a1305825bb32cd3a300e990a33cca52ec7633b9 100644
--- a/src/client/src/tscSub.c
+++ b/src/client/src/tscSub.c
@@ -301,7 +301,9 @@ void tscSaveSubscriptionProgress(void* sub) {
   char path[256];
   sprintf(path, "%s/subscribe", tsDataDir);
   if (access(path, 0) != 0) {
-    mkdir(path, 0777);
+    if (mkdir(path, 0777) != 0 && errno != EEXIST) {
+      tscError("failed to create subscribe dir: %s", path);
+    }
   }
 
   sprintf(path, "%s/subscribe/%s", tsDataDir, pSub->topic);
diff --git a/src/client/src/tscSystem.c b/src/client/src/tscSystem.c
index 75249e44eefd86f1e8ff1cc30e230ed01c5fcac4..d3c8eefbb9c37d85f1cf72a361f5ff72c9bb93d9 100644
--- a/src/client/src/tscSystem.c
+++ b/src/client/src/tscSystem.c
@@ -80,9 +80,8 @@ int32_t tscInitRpc(const char *user, const char *secret, void** pDnodeConn) {
 }
 
 void taos_init_imp() {
-  char        temp[128];
-  struct stat dirstat;
-
+  char temp[128];
+  
   errno = TSDB_CODE_SUCCESS;
   srand(taosGetTimestampSec());
   deltaToUtcInitOnce();
@@ -94,7 +93,9 @@ void taos_init_imp() {
     taosReadGlobalLogCfg();
 
     // For log directory
-    if (stat(tsLogDir, &dirstat) < 0) mkdir(tsLogDir, 0755);
+    if (mkdir(tsLogDir, 0755) != 0 && errno != EEXIST) {
+      printf("failed to create log dir:%s\n", tsLogDir);
+    }
 
     sprintf(temp, "%s/taoslog", tsLogDir);
     if (taosInitLog(temp, tsNumOfLogLines, 10) < 0) {
diff --git a/src/kit/shell/src/shellImport.c b/src/kit/shell/src/shellImport.c
index 1dea6bca702e761850b5fefbba308791655aa00a..347f99671db1bc9147c98d97ec708a3bf8bcf689 100644
--- a/src/kit/shell/src/shellImport.c
+++ b/src/kit/shell/src/shellImport.c
@@ -148,7 +148,11 @@ static void shellSourceFile(TAOS *con, char *fptr) {
   }
 
   char *fname = full_path.we_wordv[0];
-  
+  if (fname == NULL) {
+    fprintf(stderr, "ERROR: invalid filename\n");
+    return;
+  }
+
   if (access(fname, F_OK) != 0) {
     fprintf(stderr, "ERROR: file %s is not exist\n", fptr);
     
@@ -169,6 +173,7 @@ static void shellSourceFile(TAOS *con, char *fptr) {
   if (f == NULL) {
     fprintf(stderr, "ERROR: failed to open file %s\n", fname);
     wordfree(&full_path);
+    free(cmd);
     return;
   }
 
diff --git a/src/kit/taosdemo/taosdemo.c b/src/kit/taosdemo/taosdemo.c
index 81426b683a67cab0a8576236b270800837cb9e5d..ca0af9614524109787e7ac30f9a91d366ac2b164 100644
--- a/src/kit/taosdemo/taosdemo.c
+++ b/src/kit/taosdemo/taosdemo.c
@@ -43,6 +43,7 @@ extern char configDir[];
 #define MAX_DATA_SIZE    1024
 #define MAX_NUM_DATATYPE 8
 #define OPT_ABORT        1 /* –abort */
+#define STRING_LEN       512
 
 /* The options we understand. */
 static struct argp_option options[] = {
@@ -380,10 +381,11 @@ int main(int argc, char *argv[]) {
   bool insert_only = arguments.insert_only;
   char **data_type = arguments.datatype;
   int count_data_type = 0;
-  char dataString[512];
+  char dataString[STRING_LEN];
   bool do_aggreFunc = true;
 
-  memset(dataString, 0, 512);
+  memset(dataString, 0, STRING_LEN);
+  int len = 0;
 
   if (strcasecmp(data_type[0], "BINARY") == 0 || strcasecmp(data_type[0], "BOOL") == 0) {
     do_aggreFunc = false;
@@ -392,8 +394,8 @@ int main(int argc, char *argv[]) {
     if (strcasecmp(data_type[count_data_type], "") == 0) {
       break;
     }
-    strcat(dataString, data_type[count_data_type]);
-    strcat(dataString, " ");
+
+    len += snprintf(dataString + len, STRING_LEN - len, "%s ", data_type[count_data_type]);
   }
 
   FILE *fp = fopen(arguments.output_file, "a");
@@ -473,32 +475,29 @@ int main(int argc, char *argv[]) {
   sprintf(command, "create database %s;", db_name);
   taos_query(taos, command);
 
-  char cols[512] = "\0";
+  char cols[STRING_LEN] = "\0";
   int colIndex = 0;
+  len = 0;
 
   for (; colIndex < ncols_per_record - 1; colIndex++) {
     if (strcasecmp(data_type[colIndex % count_data_type], "BINARY") != 0) {
-      sprintf(command, ",f%d %s", colIndex + 1, data_type[colIndex % count_data_type]);
-      strcat(cols, command);
+      len += snprintf(cols + len, STRING_LEN - len, ",f%d %s", colIndex + 1, data_type[colIndex % count_data_type]);
     } else {
-      sprintf(command, ",f%d %s(%d)", colIndex + 1, data_type[colIndex % count_data_type], len_of_binary);
-      strcat(cols, command);
+      len += snprintf(cols + len, STRING_LEN - len, ",f%d %s(%d)", colIndex + 1, data_type[colIndex % count_data_type], len_of_binary);
     }
   }
 
   if (strcasecmp(data_type[colIndex % count_data_type], "BINARY") != 0) {
-    sprintf(command, ",f%d %s)", colIndex + 1, data_type[colIndex % count_data_type]);
+    len += snprintf(cols + len, STRING_LEN - len, ",f%d %s)", colIndex + 1, data_type[colIndex % count_data_type]);
   } else {
-    sprintf(command, ",f%d %s(%d))", colIndex + 1, data_type[colIndex % count_data_type], len_of_binary);
+    len += snprintf(cols + len, STRING_LEN - len, ",f%d %s(%d))", colIndex + 1, data_type[colIndex % count_data_type], len_of_binary);
   }
 
-  strcat(cols, command);
-
   if (!use_metric) {
     /* Create all the tables; */
     printf("Creating %d table(s)......\n", ntables);
     for (int i = 0; i < ntables; i++) {
-      sprintf(command, "create table %s.%s%d (ts timestamp%s;", db_name, tb_prefix, i, cols);
+      snprintf(command, BUFFER_SIZE, "create table %s.%s%d (ts timestamp%s;", db_name, tb_prefix, i, cols);
       queryDB(taos, command);
     }
 
@@ -508,7 +507,7 @@ int main(int argc, char *argv[]) {
   } else {
     /* Create metric table */
     printf("Creating meters super table...\n");
-    sprintf(command, "create table %s.meters (ts timestamp%s tags (areaid int, loc binary(10))", db_name, cols);
+    snprintf(command, BUFFER_SIZE, "create table %s.meters (ts timestamp%s tags (areaid int, loc binary(10))", db_name, cols);
     queryDB(taos, command);
     printf("meters created!\n");
 
@@ -522,10 +521,10 @@ int main(int argc, char *argv[]) {
         j = i % 10;
       }
     if (j % 2 == 0) {
-       sprintf(command, "create table %s.%s%d using %s.meters tags (%d,\"%s\");", db_name, tb_prefix, i, db_name, j,"shanghai");
-      } else {
-       sprintf(command, "create table %s.%s%d using %s.meters tags (%d,\"%s\");", db_name, tb_prefix, i, db_name, j,"beijing");
-      }
+      snprintf(command, BUFFER_SIZE, "create table %s.%s%d using %s.meters tags (%d,\"%s\");", db_name, tb_prefix, i, db_name, j, "shanghai");
+    } else {
+      snprintf(command, BUFFER_SIZE, "create table %s.%s%d using %s.meters tags (%d,\"%s\");", db_name, tb_prefix, i, db_name, j, "beijing");
+    }
       queryDB(taos, command);
     }
 
diff --git a/src/kit/taosdump/taosdump.c b/src/kit/taosdump/taosdump.c
index 7875ef732ce5e3b526675a26f1c2b7c1940ea445..f03b46ac470e828bdb62b76d31cea796c83fed81 100644
--- a/src/kit/taosdump/taosdump.c
+++ b/src/kit/taosdump/taosdump.c
@@ -117,8 +117,8 @@ typedef struct {
 } SDbInfo;
 
 typedef struct {
-  char name[TSDB_TABLE_NAME_LEN + 1];
-  char metric[TSDB_TABLE_NAME_LEN + 1];
+  char name[TSDB_TABLE_NAME_LEN];
+  char metric[TSDB_TABLE_NAME_LEN];
 } STableRecord;
 
 typedef struct {
@@ -871,7 +871,7 @@ int32_t taosDumpMetric(char *metric, SDumpArguments *arguments, FILE *fp) {
   int fd = -1;
   STableRecord tableRecord;
 
-  strcpy(tableRecord.metric, metric);
+  tstrncpy(tableRecord.metric, metric, TSDB_TABLE_NAME_LEN);
 
   sprintf(command, "select tbname from %s", metric);
   result = taos_query(taos, command);
diff --git a/src/mnode/src/mnodeAcct.c b/src/mnode/src/mnodeAcct.c
index 9634d2c645d8be6a7cab1147b4a551b099209d53..7ea5188b96a47981f5c42e9c28389f8cd0410409 100644
--- a/src/mnode/src/mnodeAcct.c
+++ b/src/mnode/src/mnodeAcct.c
@@ -27,7 +27,7 @@
 
 void *  tsAcctSdb = NULL;
 static int32_t tsAcctUpdateSize;
-static void    mnodeCreateRootAcct();
+static int32_t mnodeCreateRootAcct();
 
 static int32_t mnodeAcctActionDestroy(SSdbOper *pOper) {
   SAcctObj *pAcct = pOper->pObj;
@@ -79,7 +79,11 @@ static int32_t mnodeAcctActionDecode(SSdbOper *pOper) {
 
 static int32_t mnodeAcctActionRestored() {
   if (dnodeIsFirstDeploy()) {
-    mnodeCreateRootAcct();
+    int32_t code = mnodeCreateRootAcct();
+    if (code != TSDB_CODE_SUCCESS) {
+      mError("failed to create root account, reason:%s", tstrerror(code));
+      return code;
+    }
   }
 
   acctInit();
@@ -161,9 +165,9 @@ void mnodeDropUserFromAcct(SAcctObj *pAcct, SUserObj *pUser) {
   mnodeDecAcctRef(pAcct);
 }
 
-static void mnodeCreateRootAcct() {
+static int32_t mnodeCreateRootAcct() {
   int32_t numOfAccts = sdbGetNumOfRows(tsAcctSdb);
-  if (numOfAccts != 0) return;
+  if (numOfAccts != 0) return TSDB_CODE_SUCCESS;
 
   SAcctObj *pAcct = malloc(sizeof(SAcctObj));
   memset(pAcct, 0, sizeof(SAcctObj));
@@ -190,7 +194,8 @@ static void mnodeCreateRootAcct() {
     .table = tsAcctSdb,
     .pObj = pAcct,
   };
-  sdbInsertRow(&oper);
+
+  return sdbInsertRow(&oper);
 }
 
 #ifndef _ACCT
diff --git a/src/mnode/src/mnodeMain.c b/src/mnode/src/mnodeMain.c
index 298d10993beee3262a5dbebc6184a8f5a40d8b73..57bb1b2bac5c0293aabec3e81c74d8661a89fd00 100644
--- a/src/mnode/src/mnodeMain.c
+++ b/src/mnode/src/mnodeMain.c
@@ -88,9 +88,9 @@ int32_t mnodeStartSystem() {
   }
 
   mPrint("starting to initialize mnode ...");
-  struct stat dirstat;
-  if (stat(tsMnodeDir, &dirstat) < 0) {
-    mkdir(tsMnodeDir, 0755);
+  if (mkdir(tsMnodeDir, 0755) != 0 && errno != EEXIST) {
+    mError("failed to init mnode dir:%s, reason:%s", tsMnodeDir, strerror(errno));
+    return -1;
   }
 
   dnodeAllocateMnodeWqueue();
diff --git a/src/mnode/src/mnodeShow.c b/src/mnode/src/mnodeShow.c
index 36e7d13a867b6c2ccae1044758eb1c63e4c66356..30f491ec032bbac8b54dade8b883f15e618520ab 100644
--- a/src/mnode/src/mnodeShow.c
+++ b/src/mnode/src/mnodeShow.c
@@ -316,7 +316,7 @@ static int32_t mnodeProcessConnectMsg(SMnodeMsg *pMsg) {
   }
 
   sprintf(pConnectRsp->acctId, "%x", pAcct->acctId);
-  strcpy(pConnectRsp->serverVersion, version);
+  memcpy(pConnectRsp->serverVersion, version, TSDB_VERSION_LEN);
   pConnectRsp->writeAuth = pUser->writeAuth;
   pConnectRsp->superAuth = pUser->superAuth;
   
diff --git a/src/os/linux/src/linuxSysPara.c b/src/os/linux/src/linuxSysPara.c
index af2d3c2633fef495c0876b7e4be7f90d336d51fe..ca244dcd949cbc2c9819b0b6e36cfb682268e34c 100644
--- a/src/os/linux/src/linuxSysPara.c
+++ b/src/os/linux/src/linuxSysPara.c
@@ -229,7 +229,7 @@ static void taosGetSystemLocale() {  // get and set default locale
       uError("can't get locale from system, set it to en_US.UTF-8");
       strcpy(tsLocale, "en_US.UTF-8");
     } else {
-      strncpy(tsLocale, locale, tListLen(tsLocale));
+      tstrncpy(tsLocale, locale, tListLen(tsLocale));
       uError("locale not configured, set to system default:%s", tsLocale);
     }
   }
diff --git a/src/plugins/http/src/httpUtil.c b/src/plugins/http/src/httpUtil.c
index 77fc3992723fb719b165fd5d9b22674d006b4a6e..b91b89e21cf5d322b4091e24d36dd3d25a7d2cd0 100644
--- a/src/plugins/http/src/httpUtil.c
+++ b/src/plugins/http/src/httpUtil.c
@@ -32,12 +32,12 @@ bool httpCheckUsedbSql(char *sql) {
 
 void httpTimeToString(time_t t, char *buf, int buflen) {
   memset(buf, 0, (size_t)buflen);
-  char ts[30] = {0};
+  char ts[32] = {0};
 
   struct tm *ptm;
   time_t     tt = t / 1000;
   ptm = localtime(&tt);
-  strftime(ts, 64, "%Y-%m-%d %H:%M:%S", ptm);
+  strftime(ts, 31, "%Y-%m-%d %H:%M:%S", ptm);
   sprintf(buf, "%s.%03ld", ts, t % 1000);
 }
 
diff --git a/src/plugins/http/src/tgHandle.c b/src/plugins/http/src/tgHandle.c
index 61f9da63688f6d0f541a1fbae56b4d2037978269..ffb2ccb2f932a715da56364069235cd0b98ea0d3 100644
--- a/src/plugins/http/src/tgHandle.c
+++ b/src/plugins/http/src/tgHandle.c
@@ -313,7 +313,7 @@ bool tgGetPassFromUrl(HttpContext *pContext) {
     return false;
   }
 
-  strcpy(pContext->pass, pParser->path[TG_PASS_URL_POS].pos);
+  tstrncpy(pContext->pass, pParser->path[TG_PASS_URL_POS].pos, TSDB_PASSWORD_LEN);
   return true;
 }
 
diff --git a/src/util/src/tdes.c b/src/util/src/tdes.c
index 00474e4ae29a5e6f910a250d48a3c23b95c3826c..3112fb411148925bf064b356df6e8dfc708ce86e 100644
--- a/src/util/src/tdes.c
+++ b/src/util/src/tdes.c
@@ -18,6 +18,7 @@ void generate_key(unsigned char* key);
 void generate_sub_keys(unsigned char* main_key, key_set* key_sets);
 void process_message(unsigned char* message_piece, unsigned char* processed_piece, key_set* key_sets, int mode);
 
+#if 0
 int64_t taosDesGenKey() {
   unsigned int iseed = (unsigned int)time(NULL);
   srand(iseed);
@@ -27,6 +28,7 @@ int64_t taosDesGenKey() {
 
   return *((int64_t*)key);
 }
+#endif
 
 char* taosDesImp(unsigned char* key, char* src, unsigned int len, int process_mode) {
   unsigned int  number_of_blocks = len / 8;
diff --git a/src/util/src/tnote.c b/src/util/src/tnote.c
index 91d586322d47b97c02e981aa3e324391d431fa0a..31ed6e2f7bded579b75066e590c68b8bc8580a3e 100644
--- a/src/util/src/tnote.c
+++ b/src/util/src/tnote.c
@@ -87,6 +87,10 @@ void *taosThreadToOpenNewNote(void *param)
     umask(0);
 
     int fd = open(name, O_WRONLY | O_CREAT | O_TRUNC, S_IRWXU | S_IRWXG | S_IRWXO);
+    if (fd < 0) {
+      return NULL;
+    }
+
     taosLockNote(fd, pNote);
     lseek(fd, 0, SEEK_SET);
 
diff --git a/src/vnode/src/vnodeMain.c b/src/vnode/src/vnodeMain.c
index 256ef3c72baf0ccc5dd0c39b1f6452a9dfd204d6..9ec982b1decf00be2043d4c68004943c41c93587 100644
--- a/src/vnode/src/vnodeMain.c
+++ b/src/vnode/src/vnodeMain.c
@@ -75,19 +75,29 @@ int32_t vnodeCreate(SMDCreateVnodeMsg *pVnodeCfg) {
     return TSDB_CODE_SUCCESS;
   }
 
-  mkdir(tsVnodeDir, 0755);
+  if (mkdir(tsVnodeDir, 0755) != 0 && errno != EEXIST) {
+    vError("vgId:%d, failed to create vnode, reason:%s dir:%s", pVnodeCfg->cfg.vgId, strerror(errno), tsVnodeDir);
+    if (errno == EACCES) {
+      return TSDB_CODE_VND_NO_DISK_PERMISSIONS;
+    } else if (errno == ENOSPC) {
+      return TSDB_CODE_VND_NO_DISKSPACE;
+    } else if (errno == ENOENT) {
+      return TSDB_CODE_VND_NO_SUCH_FILE_OR_DIR;
+    } else {
+      return TSDB_CODE_VND_INIT_FAILED;
+    }
+  }
 
   char rootDir[TSDB_FILENAME_LEN] = {0};
   sprintf(rootDir, "%s/vnode%d", tsVnodeDir, pVnodeCfg->cfg.vgId);
-  if (mkdir(rootDir, 0755) != 0) {
-    vPrint("vgId:%d, failed to create vnode, reason:%s dir:%s", pVnodeCfg->cfg.vgId, strerror(errno), rootDir);
+  if (mkdir(rootDir, 0755) != 0 && errno != EEXIST) {
+    vError("vgId:%d, failed to create vnode, reason:%s dir:%s", pVnodeCfg->cfg.vgId, strerror(errno), rootDir);
     if (errno == EACCES) {
       return TSDB_CODE_VND_NO_DISK_PERMISSIONS;
     } else if (errno == ENOSPC) {
       return TSDB_CODE_VND_NO_DISKSPACE;
     } else if (errno == ENOENT) {
       return TSDB_CODE_VND_NO_SUCH_FILE_OR_DIR;
-    } else if (errno == EEXIST) {
     } else {
       return TSDB_CODE_VND_INIT_FAILED;
     }