diff --git a/src/client/src/tscLocal.c b/src/client/src/tscLocal.c
index 52240941f2f80be75afc0832e97acf8d421e5743..f550bbd000bc894a20b00a4d6195059a478c3da3 100644
--- a/src/client/src/tscLocal.c
+++ b/src/client/src/tscLocal.c
@@ -279,7 +279,7 @@ static void tscProcessCurrentUser(SSqlObj *pSql) {
   pExpr->resType = TSDB_DATA_TYPE_BINARY;
   
   char* vx = calloc(1, pExpr->resBytes);
-  STR_WITH_MAXSIZE_TO_VARSTR(vx, pSql->pTscObj->user, TSDB_USER_LEN);
+  STR_WITH_MAXSIZE_TO_VARSTR(vx, pSql->pTscObj->user, sizeof(pSql->pTscObj->user));
   
   tscSetLocalQueryResult(pSql, vx, pExpr->aliasName, pExpr->resType, pExpr->resBytes);
   free(vx);
diff --git a/src/client/src/tscSQLParser.c b/src/client/src/tscSQLParser.c
index 528c936e124a26f25c1c27fad2bea3310cf50059..9c64786459518a7d0226a7507a7e30d8318b7e0e 100644
--- a/src/client/src/tscSQLParser.c
+++ b/src/client/src/tscSQLParser.c
@@ -232,7 +232,7 @@ int32_t tscToSQLCmd(SSqlObj* pSql, struct SSqlInfo* pInfo) {
         pzName->n = strdequote(pzName->z);
         strncpy(pTableMetaInfo->name, pzName->z, pzName->n);
       } else {  // drop user
-        if (pzName->n > TSDB_USER_LEN) {
+        if (pzName->n >= TSDB_USER_LEN) {
           return invalidSqlErrMsg(tscGetErrorMsgPayload(pCmd), msg3);
         }
 
@@ -317,7 +317,7 @@ int32_t tscToSQLCmd(SSqlObj* pSql, struct SSqlInfo* pInfo) {
         return TSDB_CODE_TSC_INVALID_SQL;
       }
 
-      if (pName->n > TSDB_USER_LEN) {
+      if (pName->n >= TSDB_USER_LEN) {
         return invalidSqlErrMsg(tscGetErrorMsgPayload(pCmd), msg3);
       }
 
@@ -401,7 +401,7 @@ int32_t tscToSQLCmd(SSqlObj* pSql, struct SSqlInfo* pInfo) {
       SSQLToken* pName = &pUser->user;
       SSQLToken* pPwd = &pUser->passwd;
 
-      if (pName->n > TSDB_USER_LEN) {
+      if (pName->n >= TSDB_USER_LEN) {
         return invalidSqlErrMsg(tscGetErrorMsgPayload(pCmd), msg3);
       }
 
diff --git a/src/common/src/tglobal.c b/src/common/src/tglobal.c
index 12754b164bc4e50e4f6de8c41a9a072f2ce9b434..8c77f0b5f316617d2fe7ee0f1b58617cec80a084 100644
--- a/src/common/src/tglobal.c
+++ b/src/common/src/tglobal.c
@@ -718,7 +718,7 @@ static void doInitGlobalConfig() {
   cfg.cfgType = TSDB_CFG_CTYPE_B_CONFIG | TSDB_CFG_CTYPE_B_CLIENT;
   cfg.minValue = 0;
   cfg.maxValue = 0;
-  cfg.ptrLength = TSDB_USER_LEN;
+  cfg.ptrLength = TSDB_USER_LEN - 1;
   cfg.unitType = TAOS_CFG_UTYPE_NONE;
   taosInitConfigOption(cfg);
 
diff --git a/src/dnode/src/dnodeShell.c b/src/dnode/src/dnodeShell.c
index 3f3c5f2796c9704b118325dc406d82674277e168..4252e63f8d288247bb980d27fcc80e20ffb484ba 100644
--- a/src/dnode/src/dnodeShell.c
+++ b/src/dnode/src/dnodeShell.c
@@ -147,7 +147,7 @@ static int dnodeRetrieveUserAuthInfo(char *user, char *spi, char *encrypt, char
   if (code != TSDB_CODE_RPC_NOT_READY) return code;
 
   SDMAuthMsg *pMsg = rpcMallocCont(sizeof(SDMAuthMsg));
-  tstrncpy(pMsg->user, user, TSDB_USER_LEN);
+  tstrncpy(pMsg->user, user, sizeof(pMsg->user));
 
   SRpcMsg rpcMsg = {0};
   rpcMsg.pCont = pMsg;
diff --git a/src/inc/taosmsg.h b/src/inc/taosmsg.h
index 6a0219d6fc3218218d6d9cd9db0bfd82f13c8d21..0c47fad4dc94c3e4ed106ee8f47cb479d101c80e 100644
--- a/src/inc/taosmsg.h
+++ b/src/inc/taosmsg.h
@@ -321,18 +321,18 @@ typedef struct {
 } SAcctCfg;
 
 typedef struct {
-  char     user[TSDB_USER_LEN + 1];
-  char     pass[TSDB_KEY_LEN + 1];
+  char     user[TSDB_USER_LEN];
+  char     pass[TSDB_KEY_LEN];
   SAcctCfg cfg;
 } SCMCreateAcctMsg, SCMAlterAcctMsg;
 
 typedef struct {
-  char user[TSDB_USER_LEN + 1];
+  char user[TSDB_USER_LEN];
 } SCMDropUserMsg, SCMDropAcctMsg;
 
 typedef struct {
-  char   user[TSDB_USER_LEN + 1];
-  char   pass[TSDB_KEY_LEN + 1];
+  char   user[TSDB_USER_LEN];
+  char   pass[TSDB_KEY_LEN];
   int8_t privilege;
   int8_t flag;
 } SCMCreateUserMsg, SCMAlterUserMsg;
@@ -501,7 +501,7 @@ typedef struct {
 } SVnodeLoad;
 
 typedef struct {
-  char     acct[TSDB_USER_LEN + 1];
+  char     acct[TSDB_USER_LEN];
   char     db[TSDB_DB_NAME_LEN];
   int32_t  cacheBlockSize; //MB
   int32_t  totalBlocks;
@@ -750,7 +750,7 @@ typedef struct {
 } SMDAlterStreamMsg;
 
 typedef struct {
-  char user[TSDB_USER_LEN + 1];
+  char user[TSDB_USER_LEN];
   char spi;
   char encrypt;
   char secret[TSDB_KEY_LEN + 1];
diff --git a/src/mnode/inc/mnodeDef.h b/src/mnode/inc/mnodeDef.h
index 14cd4057632b1abc834a5393e4a6424dc2d1ef8d..c60c221bcc13634b2341aef02e164345e3f2fa23 100644
--- a/src/mnode/inc/mnodeDef.h
+++ b/src/mnode/inc/mnodeDef.h
@@ -155,7 +155,7 @@ typedef struct {
 
 typedef struct SDbObj {
   char    name[TSDB_DB_NAME_LEN];
-  char    acct[TSDB_USER_LEN + 1];
+  char    acct[TSDB_USER_LEN];
   int64_t createdTime;
   int32_t cfgVersion;
   SDbCfg  cfg;
@@ -172,9 +172,9 @@ typedef struct SDbObj {
 } SDbObj;
 
 typedef struct SUserObj {
-  char              user[TSDB_USER_LEN + 1];
-  char              pass[TSDB_KEY_LEN + 1];
-  char              acct[TSDB_USER_LEN + 1];
+  char              user[TSDB_USER_LEN];
+  char              pass[TSDB_KEY_LEN];
+  char              acct[TSDB_USER_LEN];
   int64_t           createdTime;
   int8_t            superAuth;
   int8_t            writeAuth;
@@ -203,7 +203,7 @@ typedef struct {
 } SAcctInfo;
 
 typedef struct SAcctObj {
-  char      user[TSDB_USER_LEN + 1];
+  char      user[TSDB_USER_LEN];
   char      pass[TSDB_KEY_LEN + 1];
   SAcctCfg  cfg;
   int32_t   acctId;
diff --git a/src/mnode/inc/mnodeProfile.h b/src/mnode/inc/mnodeProfile.h
index 30745db035c675004ae8b449c282c7fc26a2e172..c9f7cc8e2a94e6f33d55546ab547a5dc95db68f5 100644
--- a/src/mnode/inc/mnodeProfile.h
+++ b/src/mnode/inc/mnodeProfile.h
@@ -22,7 +22,7 @@ extern "C" {
 #include "mnodeDef.h"
 
 typedef struct {
-  char     user[TSDB_USER_LEN + 1];
+  char     user[TSDB_USER_LEN];
   int8_t   killed;
   uint16_t port;
   uint32_t ip;
diff --git a/src/mnode/src/mnodeProfile.c b/src/mnode/src/mnodeProfile.c
index 96bc98d6590c4effa0ae894904dcdb2f648dc69f..5b637d03bd48bc99e80208899b43f92c2bc1d8d2 100644
--- a/src/mnode/src/mnodeProfile.c
+++ b/src/mnode/src/mnodeProfile.c
@@ -97,7 +97,7 @@ SConnObj *mnodeCreateConn(char *user, uint32_t ip, uint16_t port) {
     .connId = connId,
     .stime  = taosGetTimestampMs()
   };
-  tstrncpy(connObj.user, user, TSDB_USER_LEN);
+  tstrncpy(connObj.user, user, sizeof(connObj.user));
   
   char key[10];
   sprintf(key, "%u", connId);  
@@ -235,7 +235,7 @@ static int32_t mnodeRetrieveConns(SShowObj *pShow, char *data, int32_t rows, voi
     cols++;
 
     pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
-    STR_WITH_MAXSIZE_TO_VARSTR(pWrite, pConnObj->user, TSDB_USER_LEN);
+    STR_WITH_MAXSIZE_TO_VARSTR(pWrite, pConnObj->user, sizeof(pConnObj->user));
     cols++;
 
     pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
@@ -358,7 +358,7 @@ static int32_t mnodeRetrieveQueries(SShowObj *pShow, char *data, int32_t rows, v
       cols++;
 
       pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
-      STR_WITH_MAXSIZE_TO_VARSTR(pWrite, pConnObj->user, TSDB_USER_LEN);
+      STR_WITH_MAXSIZE_TO_VARSTR(pWrite, pConnObj->user, sizeof(pConnObj->user));
       cols++;
 
       pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
@@ -479,7 +479,7 @@ static int32_t mnodeRetrieveStreams(SShowObj *pShow, char *data, int32_t rows, v
       cols++;
 
       pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
-      STR_WITH_MAXSIZE_TO_VARSTR(pWrite, pConnObj->user, TSDB_USER_LEN);
+      STR_WITH_MAXSIZE_TO_VARSTR(pWrite, pConnObj->user, sizeof(pConnObj->user));
       cols++;
 
       pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
diff --git a/src/mnode/src/mnodeUser.c b/src/mnode/src/mnodeUser.c
index aab0847a6b721e88ef1ab303ee76195d9d78cc66..ee79d962bad8fd86483518af6fec2dba3532d479 100644
--- a/src/mnode/src/mnodeUser.c
+++ b/src/mnode/src/mnodeUser.c
@@ -315,7 +315,7 @@ static int32_t mnodeRetrieveUsers(SShowObj *pShow, char *data, int32_t rows, voi
     cols = 0;
 
     pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
-    STR_WITH_MAXSIZE_TO_VARSTR(pWrite, pUser->user, TSDB_USER_LEN);
+    STR_WITH_MAXSIZE_TO_VARSTR(pWrite, pUser->user, sizeof(pUser->user));
     cols++;
 
     pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
@@ -336,7 +336,7 @@ static int32_t mnodeRetrieveUsers(SShowObj *pShow, char *data, int32_t rows, voi
     cols++;
 
     pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
-    STR_WITH_MAXSIZE_TO_VARSTR(pWrite, pUser->acct, TSDB_USER_LEN);
+    STR_WITH_MAXSIZE_TO_VARSTR(pWrite, pUser->acct, sizeof(pUser->user));
     cols++;
 
     numOfRows++;
diff --git a/src/plugins/http/inc/httpHandle.h b/src/plugins/http/inc/httpHandle.h
index 9be2796a9629055fa5fa5b77b5bdb689970542da..b8885431370999a6b11de3a2b5d5c5a6757ceba3 100644
--- a/src/plugins/http/inc/httpHandle.h
+++ b/src/plugins/http/inc/httpHandle.h
@@ -67,7 +67,7 @@
 #define HTTP_COMPRESS_IDENTITY      0
 #define HTTP_COMPRESS_GZIP          2
 
-#define HTTP_SESSION_ID_LEN         (TSDB_USER_LEN * 2 + 1)
+#define HTTP_SESSION_ID_LEN         (TSDB_USER_LEN + TSDB_PASSWORD_LEN)
 
 typedef enum {
     HTTP_CONTEXT_STATE_READY,
@@ -84,7 +84,7 @@ typedef struct {
   int   expire;
   int   access;
   void *taos;
-  char  id[HTTP_SESSION_ID_LEN + 1];
+  char  id[HTTP_SESSION_ID_LEN];
 } HttpSession;
 
 typedef enum {
diff --git a/src/plugins/http/src/gcHandle.c b/src/plugins/http/src/gcHandle.c
index 41209801233c6621c9f5a7d233c7d01718d54ba4..a99059ea34b9a307c544bc43b8469adb7fd62d97 100644
--- a/src/plugins/http/src/gcHandle.c
+++ b/src/plugins/http/src/gcHandle.c
@@ -48,7 +48,7 @@ void gcInitHandle(HttpServer* pServer) { httpAddMethod(pServer, &gcDecodeMethod)
 
 bool gcGetUserFromUrl(HttpContext* pContext) {
   HttpParser* pParser = &pContext->parser;
-  if (pParser->path[GC_USER_URL_POS].len > TSDB_USER_LEN - 1 || pParser->path[GC_USER_URL_POS].len <= 0) {
+  if (pParser->path[GC_USER_URL_POS].len >= TSDB_USER_LEN || pParser->path[GC_USER_URL_POS].len <= 0) {
     return false;
   }
 
diff --git a/src/plugins/http/src/httpAuth.c b/src/plugins/http/src/httpAuth.c
index ccf39642c9472a3ec971ecc2e763f7fa9d5fd72d..752c7d1d5080cfe56fff4c3b63de45aee4d56c53 100644
--- a/src/plugins/http/src/httpAuth.c
+++ b/src/plugins/http/src/httpAuth.c
@@ -101,7 +101,7 @@ bool httpParseTaosdAuthToken(HttpContext *pContext, char *token, int len) {
 
 bool httpGenTaosdAuthToken(HttpContext *pContext, char *token, int maxLen) {
   char buffer[TSDB_USER_LEN + TSDB_PASSWORD_LEN] = {0};
-  strncpy(buffer, pContext->user, TSDB_USER_LEN);
+  strncpy(buffer, pContext->user, sizeof(pContext->user));
   strncpy(buffer + TSDB_USER_LEN, pContext->pass, TSDB_PASSWORD_LEN);
 
   char *encrypt = taosDesEncode(KEY_DES_4, buffer, TSDB_USER_LEN + TSDB_PASSWORD_LEN);
diff --git a/src/plugins/http/src/restHandle.c b/src/plugins/http/src/restHandle.c
index d481a654d89e41ee296645fe32cb5fff38abf521..b9b096ac77e87a6bf7903d10e87522f3bc79c26e 100644
--- a/src/plugins/http/src/restHandle.c
+++ b/src/plugins/http/src/restHandle.c
@@ -61,7 +61,7 @@ void restInitHandle(HttpServer* pServer) {
 
 bool restGetUserFromUrl(HttpContext* pContext) {
   HttpParser* pParser = &pContext->parser;
-  if (pParser->path[REST_USER_URL_POS].len > TSDB_USER_LEN - 1 || pParser->path[REST_USER_URL_POS].len <= 0) {
+  if (pParser->path[REST_USER_URL_POS].len >= TSDB_USER_LEN || pParser->path[REST_USER_URL_POS].len <= 0) {
     return false;
   }
 
diff --git a/src/plugins/http/src/tgHandle.c b/src/plugins/http/src/tgHandle.c
index 945eff76112fa2db9ef34e7d5e1051870985bd0e..abc4acae654d66bcb93ed6e68744ffafdd9a2b51 100644
--- a/src/plugins/http/src/tgHandle.c
+++ b/src/plugins/http/src/tgHandle.c
@@ -306,11 +306,11 @@ void tgCleanupHandle() {
 
 bool tgGetUserFromUrl(HttpContext *pContext) {
   HttpParser *pParser = &pContext->parser;
-  if (pParser->path[TG_USER_URL_POS].len > TSDB_USER_LEN - 1 || pParser->path[TG_USER_URL_POS].len <= 0) {
+  if (pParser->path[TG_USER_URL_POS].len >= TSDB_USER_LEN || pParser->path[TG_USER_URL_POS].len <= 0) {
     return false;
   }
 
-  tstrncpy(pContext->user, pParser->path[TG_USER_URL_POS].pos, TSDB_USER_LEN);
+  tstrncpy(pContext->user, pParser->path[TG_USER_URL_POS].pos, sizeof(pContext->user));
   return true;
 }
 
diff --git a/src/plugins/monitor/src/monitorMain.c b/src/plugins/monitor/src/monitorMain.c
index ff9faa845c104d165db097595f4f7133eb313fc9..fb9fbba80db46bec3b8941c4878b023cc79817ba 100644
--- a/src/plugins/monitor/src/monitorMain.c
+++ b/src/plugins/monitor/src/monitorMain.c
@@ -175,7 +175,7 @@ static void dnodeBuildMonitorSql(char *sql, int32_t cmd) {
              ", totalConns smallint, maxConns smallint"
              ", accessState smallint"
              ") tags (acctId binary(%d))",
-             tsMonitorDbName, TSDB_USER_LEN + 1);
+             tsMonitorDbName, TSDB_USER_LEN);
   } else if (cmd == MONITOR_CMD_CREATE_TB_ACCT_ROOT) {
     snprintf(sql, SQL_LENGTH, "create table if not exists %s.acct_%s using %s.acct tags('%s')", tsMonitorDbName, "root",
              tsMonitorDbName, "root");