diff --git a/src/plugins/http/src/gcHandle.c b/src/plugins/http/src/gcHandle.c
index 176e16301bb764faae12c8329ea410d9546d6268..20cd19df9d115e296e379f8ff03c49fa3a7dd5b6 100644
--- a/src/plugins/http/src/gcHandle.c
+++ b/src/plugins/http/src/gcHandle.c
@@ -52,7 +52,7 @@ bool gcGetUserFromUrl(HttpContext* pContext) {
     return false;
   }
 
-  strcpy(pContext->user, pParser->path[GC_USER_URL_POS].pos);
+  tstrncpy(pContext->user, pParser->path[GC_USER_URL_POS].pos, TSDB_USER_LEN);
   return true;
 }
 
@@ -62,7 +62,7 @@ bool gcGetPassFromUrl(HttpContext* pContext) {
     return false;
   }
 
-  strcpy(pContext->pass, pParser->path[GC_PASS_URL_POS].pos);
+  tstrncpy(pContext->pass, pParser->path[GC_PASS_URL_POS].pos, TSDB_PASSWORD_LEN);
   return true;
 }
 
diff --git a/src/plugins/http/src/httpAuth.c b/src/plugins/http/src/httpAuth.c
index 0439083f31e5d4d7c9434535b6dd3f43a7fe6a65..69630336a25eb999c2ae8749d32fb4696a68fe67 100644
--- a/src/plugins/http/src/httpAuth.c
+++ b/src/plugins/http/src/httpAuth.c
@@ -29,6 +29,7 @@ bool httpParseBasicAuthToken(HttpContext *pContext, char *token, int len) {
   char *base64 = (char *)base64_decode(token, len, &outlen);
   if (base64 == NULL || outlen == 0) {
     httpError("context:%p, fd:%d, ip:%s, basic token:%s parsed error", pContext, pContext->fd, pContext->ipstr, token);
+    free(base64);
     return false;
   }
 
diff --git a/src/plugins/http/src/httpJson.c b/src/plugins/http/src/httpJson.c
index 901b9307745e67b1e7bd31597861e5417b7e7b96..7b49b065718b28427593bbe30c28c9ad352cf5a5 100644
--- a/src/plugins/http/src/httpJson.c
+++ b/src/plugins/http/src/httpJson.c
@@ -442,14 +442,13 @@ void httpJsonPairStatus(JsonBuf* buf, int code) {
     httpJsonPair(buf, "status", 6, "error", 5);
     httpJsonItemToken(buf);
     httpJsonPairIntVal(buf, "code", 4, code);
-    if (code >= 0) {
-      httpJsonItemToken(buf);
-      if (code == TSDB_CODE_MND_DB_NOT_SELECTED) {
-        httpJsonPair(buf, "desc", 4, "failed to create database", 23);
-      } else if (code == TSDB_CODE_MND_INVALID_TABLE_NAME) {
-        httpJsonPair(buf, "desc", 4, "failed to create table", 22);
-      } else
-        httpJsonPair(buf, "desc", 4, (char*)tstrerror(code), (int)strlen(tstrerror(code)));
+    httpJsonItemToken(buf);
+    if (code == TSDB_CODE_MND_DB_NOT_SELECTED) {
+      httpJsonPair(buf, "desc", 4, "failed to create database", 23);
+    } else if (code == TSDB_CODE_MND_INVALID_TABLE_NAME) {
+      httpJsonPair(buf, "desc", 4, "failed to create table", 22);
+    } else {
+      httpJsonPair(buf, "desc", 4, (char*)tstrerror(code), (int)strlen(tstrerror(code)));
     }
   }
 }
diff --git a/src/plugins/http/src/httpUtil.c b/src/plugins/http/src/httpUtil.c
index 694cdec0a0c84f52d61aff03311f7b355edd664a..d1a0eb90f03de4108ad16b6d2f836058f7273eb2 100644
--- a/src/plugins/http/src/httpUtil.c
+++ b/src/plugins/http/src/httpUtil.c
@@ -202,8 +202,7 @@ bool httpReMallocMultiCmdsSize(HttpContext *pContext, int cmdSize) {
               pContext->user, cmdSize);
     return false;
   }
-  memset(multiCmds->cmds + multiCmds->maxSize * (int16_t)sizeof(HttpSqlCmd), 0,
-         (size_t)(cmdSize - multiCmds->maxSize) * sizeof(HttpSqlCmd));
+  memset(multiCmds->cmds + multiCmds->maxSize, 0, (size_t)(cmdSize - multiCmds->maxSize) * sizeof(HttpSqlCmd));
   multiCmds->maxSize = (int16_t)cmdSize;
 
   return true;
diff --git a/src/plugins/http/src/restHandle.c b/src/plugins/http/src/restHandle.c
index 93094fa287b9eb272ed1c9224026594e7d12772f..2e04f562ea618db98c5a8d151365649001c44f15 100644
--- a/src/plugins/http/src/restHandle.c
+++ b/src/plugins/http/src/restHandle.c
@@ -65,7 +65,7 @@ bool restGetUserFromUrl(HttpContext* pContext) {
     return false;
   }
 
-  strcpy(pContext->user, pParser->path[REST_USER_URL_POS].pos);
+  tstrncpy(pContext->user, pParser->path[REST_USER_URL_POS].pos, TSDB_USER_LEN);
   return true;
 }
 
@@ -75,7 +75,7 @@ bool restGetPassFromUrl(HttpContext* pContext) {
     return false;
   }
 
-  strcpy(pContext->pass, pParser->path[REST_PASS_URL_POS].pos);
+  tstrncpy(pContext->pass, pParser->path[REST_PASS_URL_POS].pos, TSDB_PASSWORD_LEN);
   return true;
 }
 
diff --git a/src/plugins/http/src/tgHandle.c b/src/plugins/http/src/tgHandle.c
index fae11127e1634038a4c5d18a80cf04d07bb82f49..354fa6b07e543e056ebc1b3f6f71345f4fa9a2b9 100644
--- a/src/plugins/http/src/tgHandle.c
+++ b/src/plugins/http/src/tgHandle.c
@@ -268,10 +268,10 @@ int tgReadSchema(char *fileName) {
 
   httpPrint("open telegraf schema file:%s success", fileName);
   fseek(fp, 0, SEEK_END);
-  size_t contentSize = (size_t)ftell(fp);
+  int32_t contentSize = (int32_t)ftell(fp);
   rewind(fp);
-  char *content = (char *)calloc(contentSize * sizeof(char) + 1, 1);
-  size_t result = fread(content, 1, contentSize, fp);
+  char *  content = (char *)calloc(contentSize + 1, 1);
+  int32_t result = fread(content, 1, contentSize, fp);
   if (result != contentSize) {
     httpError("failed to read telegraf schema file:%s", fileName);
     fclose(fp);
@@ -279,6 +279,7 @@ int tgReadSchema(char *fileName) {
     return -1;
   }
 
+  content[contentSize] = 0;
   int schemaNum = tgParseSchema(content, fileName);
 
   free(content);
diff --git a/src/plugins/monitor/src/monitorMain.c b/src/plugins/monitor/src/monitorMain.c
index ea7916026cad561fb4cbb3ba529efa60b1ce615c..feb03df35d716ad045c694764b4c3ab960a1eabb 100644
--- a/src/plugins/monitor/src/monitorMain.c
+++ b/src/plugins/monitor/src/monitorMain.c
@@ -61,7 +61,7 @@ typedef struct {
   char   ep[TSDB_EP_LEN];
   int8_t cmdIndex;
   int8_t state;
-  char   sql[SQL_LENGTH];
+  char   sql[SQL_LENGTH + 1];
   void * initTimer;
   void * diskTimer;
 } SMonitorConn;
diff --git a/src/plugins/mqtt/src/mqttSystem.c b/src/plugins/mqtt/src/mqttSystem.c
index 3266579e337c5b63032e8bcf253f87cf66252b6a..e9af733d078dd00f968a4fb791d67696cccbfbfb 100644
--- a/src/plugins/mqtt/src/mqttSystem.c
+++ b/src/plugins/mqtt/src/mqttSystem.c
@@ -164,7 +164,7 @@ void mqtt_PublishCallback(void** unused, struct mqtt_response_publish* published
 void* mqttClientRefresher(void* client) {
   while (mttIsRuning) {
     mqtt_sync((struct mqtt_client*)client);
-    usleep(100000U);
+    taosMsleep(100);
   }
   mqttPrint("Exit  mqttClientRefresher");
   return NULL;