diff --git a/src/client/src/TSDBJNIConnector.c b/src/client/src/TSDBJNIConnector.c
index 9530bc26b4c8e5f33aa8c576dc1ffef1c9f85697..1a4ad8f050057be6e5b6d26a61720a615b84d1c7 100644
--- a/src/client/src/TSDBJNIConnector.c
+++ b/src/client/src/TSDBJNIConnector.c
@@ -227,12 +227,12 @@ JNIEXPORT jlong JNICALL Java_com_taosdata_jdbc_TSDBJNIConnector_connectImp(JNIEn
   }
 
   if (user == NULL) {
-    jniTrace("jobj:%p, user is null, use tsDefaultUser", jobj);
-    user = tsDefaultUser;
+    jniTrace("jobj:%p, user is null, use default user %s", jobj, TSDB_DEFAULT_USER);
+    user = TSDB_DEFAULT_USER;
   }
   if (pass == NULL) {
-    jniTrace("jobj:%p, pass is null, use tsDefaultPass", jobj);
-    pass = tsDefaultPass;
+    jniTrace("jobj:%p, pass is null, use default password", jobj);
+    pass = TSDB_DEFAULT_PASS;
   }
 
   /*
@@ -252,8 +252,8 @@ JNIEXPORT jlong JNICALL Java_com_taosdata_jdbc_TSDBJNIConnector_connectImp(JNIEn
 
   if (host != NULL) (*env)->ReleaseStringUTFChars(env, jhost, host);
   if (dbname != NULL) (*env)->ReleaseStringUTFChars(env, jdbName, dbname);
-  if (user != NULL && user != tsDefaultUser) (*env)->ReleaseStringUTFChars(env, juser, user);
-  if (pass != NULL && pass != tsDefaultPass) (*env)->ReleaseStringUTFChars(env, jpass, pass);
+  if (user != NULL && user != (const char *)TSDB_DEFAULT_USER) (*env)->ReleaseStringUTFChars(env, juser, user);
+  if (pass != NULL && pass != (const char *)TSDB_DEFAULT_PASS) (*env)->ReleaseStringUTFChars(env, jpass, pass);
 
   return ret;
 }
diff --git a/src/common/inc/tglobal.h b/src/common/inc/tglobal.h
index eaceea468b4d2d5020e11e19b1d7e8b67cbf915c..980635588ee537702287073bcf8c8e361f5e221b 100644
--- a/src/common/inc/tglobal.h
+++ b/src/common/inc/tglobal.h
@@ -92,10 +92,6 @@ extern int32_t tsNumOfMnodes;
 extern int32_t tsMaxShellConns;
 extern int32_t tsMaxTables;
 
-extern char tsDefaultDB[];
-extern char tsDefaultUser[];
-extern char tsDefaultPass[];
-
 extern char tsMqttBrokerAddress[];
 extern char tsMqttBrokerClientId[];
 
diff --git a/src/common/src/tglobal.c b/src/common/src/tglobal.c
index e80597ca954652abd450f20738be0ecca849a04a..2ed6ef3ab7a77ea3f6bc6def2d8456828c6ef1c5 100644
--- a/src/common/src/tglobal.c
+++ b/src/common/src/tglobal.c
@@ -109,10 +109,6 @@ int32_t tsReplications  = TSDB_DEFAULT_REPLICA_NUM;
 int16_t tsAffectedRowsMod = 0;
 int32_t tsNumOfMnodes = 3;
 int32_t tsMaxShellConns = 5000;
-
-char    tsDefaultDB[TSDB_DB_NAME_LEN] = {0};
-char    tsDefaultUser[64] = "root";
-char    tsDefaultPass[64] = "taosdata";
 int32_t tsMaxConnections = 5000;
 
 int32_t tsBalanceInterval = 300;  // seconds
@@ -713,37 +709,6 @@ static void doInitGlobalConfig() {
   cfg.unitType = TAOS_CFG_UTYPE_NONE;
   taosInitConfigOption(cfg);
 
-  // login configs
-  cfg.option = "defaultDB";
-  cfg.ptr = tsDefaultDB;
-  cfg.valType = TAOS_CFG_VTYPE_STRING;
-  cfg.cfgType = TSDB_CFG_CTYPE_B_CONFIG | TSDB_CFG_CTYPE_B_CLIENT;
-  cfg.minValue = 0;
-  cfg.maxValue = 0;
-  cfg.ptrLength = TSDB_DB_NAME_LEN - 1;
-  cfg.unitType = TAOS_CFG_UTYPE_NONE;
-  taosInitConfigOption(cfg);
-
-  cfg.option = "defaultUser";
-  cfg.ptr = tsDefaultUser;
-  cfg.valType = TAOS_CFG_VTYPE_STRING;
-  cfg.cfgType = TSDB_CFG_CTYPE_B_CONFIG | TSDB_CFG_CTYPE_B_CLIENT;
-  cfg.minValue = 0;
-  cfg.maxValue = 0;
-  cfg.ptrLength = TSDB_USER_LEN - 1;
-  cfg.unitType = TAOS_CFG_UTYPE_NONE;
-  taosInitConfigOption(cfg);
-
-  cfg.option = "defaultPass";
-  cfg.ptr = tsDefaultPass;
-  cfg.valType = TAOS_CFG_VTYPE_STRING;
-  cfg.cfgType = TSDB_CFG_CTYPE_B_CONFIG | TSDB_CFG_CTYPE_B_CLIENT | TSDB_CFG_CTYPE_B_NOT_PRINT;
-  cfg.minValue = 0;
-  cfg.maxValue = 0;
-  cfg.ptrLength = TSDB_PASSWORD_LEN - 1;
-  cfg.unitType = TAOS_CFG_UTYPE_NONE;
-  taosInitConfigOption(cfg);
-
   cfg.option = "mqttBrokerAddress";
   cfg.ptr = tsMqttBrokerAddress;
   cfg.valType = TAOS_CFG_VTYPE_STRING;
diff --git a/src/cq/test/cqtest.c b/src/cq/test/cqtest.c
index 1416a591bec5e4ec61e7a4581db955e91feec2e8..d06f14d53fcc6e434401636ee91f6c9bd5a44e5e 100644
--- a/src/cq/test/cqtest.c
+++ b/src/cq/test/cqtest.c
@@ -48,8 +48,8 @@ int main(int argc, char *argv[]) {
   taosInitLog("cq.log", 100000, 10);
 
   SCqCfg cqCfg;
-  strcpy(cqCfg.user, "root");
-  strcpy(cqCfg.pass, "taosdata");
+  strcpy(cqCfg.user, TSDB_DEFAULT_USER);
+  strcpy(cqCfg.pass, TSDB_DEFAULT_PASS);
   cqCfg.vgId = 2;
   cqCfg.cqWrite = writeToQueue;
 
diff --git a/src/inc/taosdef.h b/src/inc/taosdef.h
index 6de7f672913f7adb94ac2fc853b2596480e2a4cb..d8e21c159b08130dc8a4d3e35c0a438a72997391 100644
--- a/src/inc/taosdef.h
+++ b/src/inc/taosdef.h
@@ -83,6 +83,9 @@ extern const int32_t TYPE_BYTES[11];
 #define TSDB_DATA_NULL_STR              "NULL"
 #define TSDB_DATA_NULL_STR_L            "null"
 
+#define TSDB_DEFAULT_USER               "root"
+#define TSDB_DEFAULT_PASS               "taosdata"
+
 #define TSDB_TRUE   1
 #define TSDB_FALSE  0
 #define TSDB_OK     0
diff --git a/src/kit/shell/src/shellEngine.c b/src/kit/shell/src/shellEngine.c
index 7705db4b27e252a01933950fd309bd7ca179a008..f2ba5201ba0c3b4d454dc9de047ccd0ceb4a6884 100644
--- a/src/kit/shell/src/shellEngine.c
+++ b/src/kit/shell/src/shellEngine.c
@@ -56,11 +56,11 @@ TAOS *shellInit(SShellArguments *args) {
   if (args->is_use_passwd) {
     if (args->password == NULL) args->password = getpass("Enter password: ");
   } else {
-    args->password = tsDefaultPass;
+    args->password = TSDB_DEFAULT_PASS;
   }
 
   if (args->user == NULL) {
-    args->user = tsDefaultUser;
+    args->user = TSDB_DEFAULT_USER;
   }
 
   taos_init();
diff --git a/src/kit/taosdemo/taosdemo.c b/src/kit/taosdemo/taosdemo.c
index ab5781e74fc49da5c70d73ec5bc57f9808f4fb27..4a455271fff51e1bd9438ce01d044eee3760f6c2 100644
--- a/src/kit/taosdemo/taosdemo.c
+++ b/src/kit/taosdemo/taosdemo.c
@@ -306,7 +306,7 @@ double getCurrentTime();
 void callBack(void *param, TAOS_RES *res, int code);
 
 int main(int argc, char *argv[]) {
-  SDemoArguments arguments = {NULL,            // host
+  SDemoArguments arguments = {  NULL,            // host
                                 0,               // port
                                 "root",          // user
                                 "taosdata",      // password
diff --git a/src/kit/taosdump/taosdump.c b/src/kit/taosdump/taosdump.c
index ee792c51166b090dd8ea104120ae5fd105791948..0b881864f2253de5caeebbe501c9be440d5b262d 100644
--- a/src/kit/taosdump/taosdump.c
+++ b/src/kit/taosdump/taosdump.c
@@ -34,6 +34,8 @@
 #include "taosdef.h"
 #include "tutil.h"
 
+#include "tglobal.h"
+
 #define COMMAND_SIZE 65536
 #define DEFAULT_DUMP_FILE "taosdump.sql"
 
@@ -324,7 +326,7 @@ void taosFreeDbInfos();
 int main(int argc, char *argv[]) {
   SDumpArguments arguments = {
     // connection option
-    NULL, "root", "taosdata", 0,
+    NULL, TSDB_DEFAULT_USER, TSDB_DEFAULT_PASS, 0,
     // output file
     DEFAULT_DUMP_FILE, DEFAULT_DUMP_FILE, NULL,
     // dump unit option
@@ -502,7 +504,7 @@ int taosDumpOut(SDumpArguments *arguments) {
     }
 
     strncpy(dbInfos[count]->name, (char *)row[TSDB_SHOW_DB_NAME_INDEX], fields[TSDB_SHOW_DB_NAME_INDEX].bytes);
-    if (strcmp(arguments->user, "root") == 0) {
+    if (strcmp(arguments->user, TSDB_DEFAULT_USER) == 0) {
       dbInfos[count]->replica = (int)(*((int16_t *)row[TSDB_SHOW_DB_REPLICA_INDEX]));
       dbInfos[count]->days = (int)(*((int16_t *)row[TSDB_SHOW_DB_DAYS_INDEX]));
       dbInfos[count]->keep = *((int *)row[TSDB_SHOW_DB_KEEP_INDEX]);
diff --git a/src/mnode/src/mnodeAcct.c b/src/mnode/src/mnodeAcct.c
index 3fcb3849aafa8221cd7c4450fd851e5dce2672f4..ad52a4c3acc2d89463d14df00d120711a767ffc2 100644
--- a/src/mnode/src/mnodeAcct.c
+++ b/src/mnode/src/mnodeAcct.c
@@ -25,6 +25,8 @@
 #include "mnodeSdb.h"
 #include "mnodeUser.h"
 
+#include "tglobal.h"
+
 void *  tsAcctSdb = NULL;
 static int32_t tsAcctUpdateSize;
 static int32_t mnodeCreateRootAcct();
@@ -174,8 +176,8 @@ static int32_t mnodeCreateRootAcct() {
 
   SAcctObj *pAcct = malloc(sizeof(SAcctObj));
   memset(pAcct, 0, sizeof(SAcctObj));
-  strcpy(pAcct->user, "root");
-  taosEncryptPass((uint8_t*)"taosdata", strlen("taosdata"), pAcct->pass);
+  strcpy(pAcct->user, TSDB_DEFAULT_USER);
+  taosEncryptPass((uint8_t *)TSDB_DEFAULT_PASS, strlen(TSDB_DEFAULT_PASS), pAcct->pass);
   pAcct->cfg = (SAcctCfg){
     .maxUsers           = 10,
     .maxDbs             = 64,
@@ -207,4 +209,4 @@ int32_t acctInit() { return TSDB_CODE_SUCCESS; }
 void    acctCleanUp() {}
 int32_t acctCheck(void *pAcct, EAcctGrantType type) { return TSDB_CODE_SUCCESS; }
 
-#endif
\ No newline at end of file
+#endif
diff --git a/src/mnode/src/mnodeDb.c b/src/mnode/src/mnodeDb.c
index 081fe289542e42dbc8817b7fa0ad340eb34f9953..9709d7786aaa3f6e0f563bd85ed453679ce0c4f6 100644
--- a/src/mnode/src/mnodeDb.c
+++ b/src/mnode/src/mnodeDb.c
@@ -478,7 +478,7 @@ static int32_t mnodeGetDbMeta(STableMetaMsg *pMeta, SShowObj *pShow, void *pConn
   cols++;
 
 #ifndef __CLOUD_VERSION__
-  if (strcmp(pUser->user, "root") == 0) {
+  if (strcmp(pUser->user, TSDB_DEFAULT_USER) == 0) {
 #endif
     pShow->bytes[cols] = 4;
     pSchema[cols].type = TSDB_DATA_TYPE_INT;
@@ -490,7 +490,7 @@ static int32_t mnodeGetDbMeta(STableMetaMsg *pMeta, SShowObj *pShow, void *pConn
 #endif
 
 #ifndef __CLOUD_VERSION__
-  if (strcmp(pUser->user, "root") == 0) {
+  if (strcmp(pUser->user, TSDB_DEFAULT_USER) == 0) {
 #endif
     pShow->bytes[cols] = 2;
     pSchema[cols].type = TSDB_DATA_TYPE_SMALLINT;
@@ -514,7 +514,7 @@ static int32_t mnodeGetDbMeta(STableMetaMsg *pMeta, SShowObj *pShow, void *pConn
   cols++;
 
 #ifndef __CLOUD_VERSION__
-  if (strcmp(pUser->user, "root") == 0) {
+  if (strcmp(pUser->user, TSDB_DEFAULT_USER) == 0) {
 #endif
     pShow->bytes[cols] = 4;
     pSchema[cols].type = TSDB_DATA_TYPE_INT;
@@ -628,7 +628,7 @@ static int32_t mnodeRetrieveDbs(SShowObj *pShow, char *data, int32_t rows, void
     cols++;
 
 #ifndef __CLOUD_VERSION__
-    if (strcmp(pUser->user, "root") == 0) {
+    if (strcmp(pUser->user, TSDB_DEFAULT_USER) == 0) {
 #endif
       pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
       *(int32_t *)pWrite = pDb->numOfVgroups;
@@ -638,7 +638,7 @@ static int32_t mnodeRetrieveDbs(SShowObj *pShow, char *data, int32_t rows, void
 #endif
 
 #ifndef __CLOUD_VERSION__
-    if (strcmp(pUser->user, "root") == 0) {
+    if (strcmp(pUser->user, TSDB_DEFAULT_USER) == 0) {
 #endif
       pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
       *(int16_t *)pWrite = pDb->cfg.replications;
@@ -659,7 +659,7 @@ static int32_t mnodeRetrieveDbs(SShowObj *pShow, char *data, int32_t rows, void
     cols++;
 
 #ifndef __CLOUD_VERSION__
-    if (strcmp(pUser->user, "root") == 0) {
+    if (strcmp(pUser->user, TSDB_DEFAULT_USER) == 0) {
 #endif
       pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
       *(int32_t *)pWrite = pDb->cfg.maxTables;  // table num can be created should minus 1
diff --git a/src/mnode/src/mnodeDnode.c b/src/mnode/src/mnodeDnode.c
index bd95b0cc515ca48d41330cbcaa77264132d43c52..e3ea08aeceb34a20cdd1e3df9122d9dc7f4f918f 100644
--- a/src/mnode/src/mnodeDnode.c
+++ b/src/mnode/src/mnodeDnode.c
@@ -254,7 +254,7 @@ static int32_t mnodeProcessCfgDnodeMsg(SMnodeMsg *pMsg) {
     // TODO temporary disabled for compiling: strcpy(pCmCfgDnode->ep, pCmCfgDnode->ep); 
   }
 
-  if (strcmp(pMsg->pUser->user, "root") != 0) {
+  if (strcmp(pMsg->pUser->user, TSDB_DEFAULT_USER) != 0) {
     return TSDB_CODE_MND_NO_RIGHTS;
   }
 
@@ -480,7 +480,7 @@ static int32_t mnodeDropDnodeByEp(char *ep, SMnodeMsg *pMsg) {
 static int32_t mnodeProcessCreateDnodeMsg(SMnodeMsg *pMsg) {
   SCMCreateDnodeMsg *pCreate = pMsg->rpcMsg.pCont;
 
-  if (strcmp(pMsg->pUser->user, "root") != 0) {
+  if (strcmp(pMsg->pUser->user, TSDB_DEFAULT_USER) != 0) {
     return TSDB_CODE_MND_NO_RIGHTS;
   } else {
     return mnodeCreateDnode(pCreate->ep, pMsg);
@@ -490,7 +490,7 @@ static int32_t mnodeProcessCreateDnodeMsg(SMnodeMsg *pMsg) {
 static int32_t mnodeProcessDropDnodeMsg(SMnodeMsg *pMsg) {
   SCMDropDnodeMsg *pDrop = pMsg->rpcMsg.pCont;
 
-  if (strcmp(pMsg->pUser->user, "root") != 0) {
+  if (strcmp(pMsg->pUser->user, TSDB_DEFAULT_USER) != 0) {
     return TSDB_CODE_MND_NO_RIGHTS;
   } else {
     return mnodeDropDnodeByEp(pDrop->ep, pMsg);
@@ -501,7 +501,7 @@ static int32_t mnodeGetDnodeMeta(STableMetaMsg *pMeta, SShowObj *pShow, void *pC
   SUserObj *pUser = mnodeGetUserFromConn(pConn);
   if (pUser == NULL) return 0;
 
-  if (strcmp(pUser->pAcct->user, "root") != 0) {
+  if (strcmp(pUser->pAcct->user, TSDB_DEFAULT_USER) != 0) {
     mnodeDecUserRef(pUser);
     return TSDB_CODE_MND_NO_RIGHTS;
   }
@@ -630,7 +630,7 @@ static int32_t mnodeGetModuleMeta(STableMetaMsg *pMeta, SShowObj *pShow, void *p
   SUserObj *pUser = mnodeGetUserFromConn(pConn);
   if (pUser == NULL) return 0;
 
-  if (strcmp(pUser->user, "root") != 0)  {
+  if (strcmp(pUser->user, TSDB_DEFAULT_USER) != 0)  {
     mnodeDecUserRef(pUser);
     return TSDB_CODE_MND_NO_RIGHTS;
   }
@@ -740,7 +740,7 @@ static int32_t mnodeGetConfigMeta(STableMetaMsg *pMeta, SShowObj *pShow, void *p
   SUserObj *pUser = mnodeGetUserFromConn(pConn);
   if (pUser == NULL) return 0;
 
-  if (strcmp(pUser->user, "root") != 0)  {
+  if (strcmp(pUser->user, TSDB_DEFAULT_USER) != 0)  {
     mnodeDecUserRef(pUser);
     return TSDB_CODE_MND_NO_RIGHTS;
   }
@@ -827,7 +827,7 @@ static int32_t mnodeGetVnodeMeta(STableMetaMsg *pMeta, SShowObj *pShow, void *pC
   SUserObj *pUser = mnodeGetUserFromConn(pConn);
   if (pUser == NULL) return 0;
   
-  if (strcmp(pUser->user, "root") != 0)  {
+  if (strcmp(pUser->user, TSDB_DEFAULT_USER) != 0)  {
     mnodeDecUserRef(pUser);
     return TSDB_CODE_MND_NO_RIGHTS;
   }
diff --git a/src/mnode/src/mnodeMnode.c b/src/mnode/src/mnodeMnode.c
index 41bd6974dbe9eb422b3b72ec650bf06b995276df..219fb0b0a3b1e33292a55fc866e0982078e18469 100644
--- a/src/mnode/src/mnodeMnode.c
+++ b/src/mnode/src/mnodeMnode.c
@@ -31,6 +31,8 @@
 #include "mnodeShow.h"
 #include "mnodeUser.h"
 
+#include "tglobal.h"
+
 static void *        tsMnodeSdb = NULL;
 static int32_t       tsMnodeUpdateSize = 0;
 static SRpcIpSet     tsMnodeIpSetForShell;
@@ -333,7 +335,7 @@ static int32_t mnodeGetMnodeMeta(STableMetaMsg *pMeta, SShowObj *pShow, void *pC
   SUserObj *pUser = mnodeGetUserFromConn(pConn);
   if (pUser == NULL) return 0;
 
-  if (strcmp(pUser->pAcct->user, "root") != 0)  {
+  if (strcmp(pUser->pAcct->user, TSDB_DEFAULT_USER) != 0)  {
     mnodeDecUserRef(pUser);
     return TSDB_CODE_MND_NO_RIGHTS;
   }
diff --git a/src/mnode/src/mnodeProfile.c b/src/mnode/src/mnodeProfile.c
index d035f19b6ff6d0168471fb57da5ab0b560835cc9..2a895c9496f1c5243770099285eea1fce27b1ed2 100644
--- a/src/mnode/src/mnodeProfile.c
+++ b/src/mnode/src/mnodeProfile.c
@@ -169,7 +169,7 @@ static void *mnodeGetNextConn(SHashMutableIterator *pIter, SConnObj **pConn) {
 static int32_t mnodeGetConnsMeta(STableMetaMsg *pMeta, SShowObj *pShow, void *pConn) {
   SUserObj *pUser = mnodeGetUserFromConn(pConn);
   if (pUser == NULL) return 0;
-  if (strcmp(pUser->user, "root") != 0) return TSDB_CODE_MND_NO_RIGHTS;
+  if (strcmp(pUser->user, TSDB_DEFAULT_USER) != 0) return TSDB_CODE_MND_NO_RIGHTS;
   
   int32_t cols = 0;
   SSchema *pSchema = pMeta->schema;
@@ -294,7 +294,7 @@ int32_t mnodeSaveQueryStreamList(SConnObj *pConn, SCMHeartBeatMsg *pHBMsg) {
 static int32_t mnodeGetQueryMeta(STableMetaMsg *pMeta, SShowObj *pShow, void *pConn) {
   SUserObj *pUser = mnodeGetUserFromConn(pConn);
   if (pUser == NULL) return 0;
-  if (strcmp(pUser->user, "root") != 0) return TSDB_CODE_MND_NO_RIGHTS;
+  if (strcmp(pUser->user, TSDB_DEFAULT_USER) != 0) return TSDB_CODE_MND_NO_RIGHTS;
 
   int32_t cols = 0;
   SSchema *pSchema = pMeta->schema;
@@ -403,7 +403,7 @@ static int32_t mnodeRetrieveQueries(SShowObj *pShow, char *data, int32_t rows, v
 static int32_t mnodeGetStreamMeta(STableMetaMsg *pMeta, SShowObj *pShow, void *pConn) {
   SUserObj *pUser = mnodeGetUserFromConn(pConn);
   if (pUser == NULL) return 0;
-  if (strcmp(pUser->user, "root") != 0) return TSDB_CODE_MND_NO_RIGHTS;
+  if (strcmp(pUser->user, TSDB_DEFAULT_USER) != 0) return TSDB_CODE_MND_NO_RIGHTS;
 
   int32_t cols = 0;
   SSchema *pSchema = pMeta->schema;
@@ -531,7 +531,7 @@ static int32_t mnodeRetrieveStreams(SShowObj *pShow, char *data, int32_t rows, v
 
 static int32_t mnodeProcessKillQueryMsg(SMnodeMsg *pMsg) {
   SUserObj *pUser = pMsg->pUser;
-  if (strcmp(pUser->user, "root") != 0) return TSDB_CODE_MND_NO_RIGHTS;
+  if (strcmp(pUser->user, TSDB_DEFAULT_USER) != 0) return TSDB_CODE_MND_NO_RIGHTS;
 
   SCMKillQueryMsg *pKill = pMsg->rpcMsg.pCont;
   mPrint("kill query msg is received, queryId:%s", pKill->queryId);
@@ -561,7 +561,7 @@ static int32_t mnodeProcessKillQueryMsg(SMnodeMsg *pMsg) {
 
 static int32_t mnodeProcessKillStreamMsg(SMnodeMsg *pMsg) {
   SUserObj *pUser = pMsg->pUser;
-  if (strcmp(pUser->user, "root") != 0) return TSDB_CODE_MND_NO_RIGHTS;
+  if (strcmp(pUser->user, TSDB_DEFAULT_USER) != 0) return TSDB_CODE_MND_NO_RIGHTS;
 
   SCMKillQueryMsg *pKill = pMsg->rpcMsg.pCont;
   mPrint("kill stream msg is received, streamId:%s", pKill->queryId);
@@ -591,7 +591,7 @@ static int32_t mnodeProcessKillStreamMsg(SMnodeMsg *pMsg) {
 
 static int32_t mnodeProcessKillConnectionMsg(SMnodeMsg *pMsg) {
   SUserObj *pUser = pMsg->pUser;
-  if (strcmp(pUser->user, "root") != 0) return TSDB_CODE_MND_NO_RIGHTS;
+  if (strcmp(pUser->user, TSDB_DEFAULT_USER) != 0) return TSDB_CODE_MND_NO_RIGHTS;
 
   SCMKillConnMsg *pKill = pMsg->rpcMsg.pCont;
   SConnObj *      pConn = taosCacheAcquireByName(tsMnodeConnCache, pKill->queryId);
diff --git a/src/mnode/src/mnodeUser.c b/src/mnode/src/mnodeUser.c
index 07de4cf6411e2f459ee17103a81fb9c72842bbef..b559116e585001e70e3081a9d669f81ae34962ea 100644
--- a/src/mnode/src/mnodeUser.c
+++ b/src/mnode/src/mnodeUser.c
@@ -105,10 +105,10 @@ static int32_t mnodeUserActionRestored() {
   int32_t numOfRows = sdbGetNumOfRows(tsUserSdb);
   if (numOfRows <= 0 && dnodeIsFirstDeploy()) {
     mPrint("dnode first deploy, create root user");
-    SAcctObj *pAcct = mnodeGetAcct("root");
-    mnodeCreateUser(pAcct, "root", "taosdata", NULL);
+    SAcctObj *pAcct = mnodeGetAcct(TSDB_DEFAULT_USER);
+    mnodeCreateUser(pAcct, TSDB_DEFAULT_USER, TSDB_DEFAULT_PASS, NULL);
     mnodeCreateUser(pAcct, "monitor", tsInternalPass, NULL);
-    mnodeCreateUser(pAcct, "_root", tsInternalPass, NULL);
+    mnodeCreateUser(pAcct, "_"TSDB_DEFAULT_USER, tsInternalPass, NULL);
     mnodeDecAcctRef(pAcct);
   }
 
@@ -222,7 +222,7 @@ int32_t mnodeCreateUser(SAcctObj *pAcct, char *name, char *pass, void *pMsg) {
   pUser->createdTime = taosGetTimestampMs();
   pUser->superAuth = 0;
   pUser->writeAuth = 1;
-  if (strcmp(pUser->user, "root") == 0 || strcmp(pUser->user, pUser->acct) == 0) {
+  if (strcmp(pUser->user, TSDB_DEFAULT_USER) == 0 || strcmp(pUser->user, pUser->acct) == 0) {
     pUser->superAuth = 1;
   }
 
@@ -404,12 +404,12 @@ static int32_t mnodeProcessAlterUserMsg(SMnodeMsg *pMsg) {
 
   if ((pAlter->flag & TSDB_ALTER_USER_PASSWD) != 0) {
     bool hasRight = false;
-    if (strcmp(pOperUser->user, "root") == 0) {
+    if (strcmp(pOperUser->user, TSDB_DEFAULT_USER) == 0) {
       hasRight = true;
     } else if (strcmp(pUser->user, pOperUser->user) == 0) {
       hasRight = true;
     } else if (pOperUser->superAuth) {
-      if (strcmp(pUser->user, "root") == 0) {
+      if (strcmp(pUser->user, TSDB_DEFAULT_USER) == 0) {
         hasRight = false;
       } else if (strcmp(pOperUser->acct, pUser->acct) != 0) {
         hasRight = false;
@@ -429,16 +429,16 @@ static int32_t mnodeProcessAlterUserMsg(SMnodeMsg *pMsg) {
   } else if ((pAlter->flag & TSDB_ALTER_USER_PRIVILEGES) != 0) {
     bool hasRight = false;
 
-    if (strcmp(pUser->user, "root") == 0) {
+    if (strcmp(pUser->user, TSDB_DEFAULT_USER) == 0) {
       hasRight = false;
     } else if (strcmp(pUser->user, pUser->acct) == 0) {
       hasRight = false;
-    } else if (strcmp(pOperUser->user, "root") == 0) {
+    } else if (strcmp(pOperUser->user, TSDB_DEFAULT_USER) == 0) {
       hasRight = true;
     } else if (strcmp(pUser->user, pOperUser->user) == 0) {
       hasRight = false;
     } else if (pOperUser->superAuth) {
-      if (strcmp(pUser->user, "root") == 0) {
+      if (strcmp(pUser->user, TSDB_DEFAULT_USER) == 0) {
         hasRight = false;
       } else if (strcmp(pOperUser->acct, pUser->acct) != 0) {
         hasRight = false;
@@ -492,9 +492,9 @@ static int32_t mnodeProcessDropUserMsg(SMnodeMsg *pMsg) {
   }
 
   bool hasRight = false;
-  if (strcmp(pUser->user, "root") == 0) {
+  if (strcmp(pUser->user, TSDB_DEFAULT_USER) == 0) {
     hasRight = false;
-  } else if (strcmp(pOperUser->user, "root") == 0) {
+  } else if (strcmp(pOperUser->user, TSDB_DEFAULT_USER) == 0) {
     hasRight = true;
   } else if (strcmp(pUser->user, pOperUser->user) == 0) {
     hasRight = false;
diff --git a/src/plugins/monitor/src/monitorMain.c b/src/plugins/monitor/src/monitorMain.c
index feb03df35d716ad045c694764b4c3ab960a1eabb..4ea27f4839cad1608df01eeca0874ce5f35b1d69 100644
--- a/src/plugins/monitor/src/monitorMain.c
+++ b/src/plugins/monitor/src/monitorMain.c
@@ -177,8 +177,8 @@ static void dnodeBuildMonitorSql(char *sql, int32_t cmd) {
              ") tags (acctId binary(%d))",
              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");
+    snprintf(sql, SQL_LENGTH, "create table if not exists %s.acct_%s using %s.acct tags('%s')", tsMonitorDbName, TSDB_DEFAULT_USER,
+             tsMonitorDbName, TSDB_DEFAULT_USER);
   } else if (cmd == MONITOR_CMD_CREATE_TB_SLOWQUERY) {
     snprintf(sql, SQL_LENGTH,
              "create table if not exists %s.slowquery(ts timestamp, username "
diff --git a/tests/test/c/importOneRow.c b/tests/test/c/importOneRow.c
index 0690d8983786341c09d43ad1d69cf527e758203f..858926106c14afa6fb35bb66d44075c04add89f0 100644
--- a/tests/test/c/importOneRow.c
+++ b/tests/test/c/importOneRow.c
@@ -109,7 +109,7 @@ void* taos_execute(void *param) {
 
   taosGetFqdnPortFromEp(tsFirst, fqdn, &port);
 
-  void *taos = taos_connect(fqdn, tsDefaultUser, tsDefaultPass, NULL, port);
+  void *taos = taos_connect(fqdn, "root", "taosdata", NULL, port);
   if (taos == NULL) taos_error(taos);
 
   char sql[1024] = {0};
diff --git a/tests/test/c/importPerTable.c b/tests/test/c/importPerTable.c
index 407a818fa5234e2f64c11ffcd4a5b4b75c574558..b4e8b6870342845ddcc75c2703fbe54119c423f8 100644
--- a/tests/test/c/importPerTable.c
+++ b/tests/test/c/importPerTable.c
@@ -73,7 +73,7 @@ void createDbAndTable() {
 
   taosGetFqdnPortFromEp(tsFirst, fqdn, &port);
 
-  con = taos_connect(fqdn, tsDefaultUser, tsDefaultPass, NULL, port);
+  con = taos_connect(fqdn, "root", "taosdata", NULL, port);
   if (con == NULL) {
     pError("failed to connect to DB, reason:%s", taos_errstr(con));
     exit(1);
@@ -200,7 +200,7 @@ void *syncTest(void *param) {
 
   taosGetFqdnPortFromEp(tsFirst, fqdn, &port);
 
-  con = taos_connect(fqdn, tsDefaultUser, tsDefaultPass, NULL, port);
+  con = taos_connect(fqdn, "root", "taosdata", NULL, port);
   if (con == NULL) {
     pError("index:%d, failed to connect to DB, reason:%s", pInfo->threadIndex, taos_errstr(con));
     exit(1);
diff --git a/tests/test/c/insertPerRow.c b/tests/test/c/insertPerRow.c
index 7a97b21e0a7fb6077cd09ac6dab98115f0e1e476..9b71ce50dd60fa8dddb7579d9f8a052b812d7b13 100644
--- a/tests/test/c/insertPerRow.c
+++ b/tests/test/c/insertPerRow.c
@@ -71,7 +71,7 @@ void createDbAndTable() {
   char fqdn[TSDB_FQDN_LEN];
   uint16_t port;
   taosGetFqdnPortFromEp(tsFirst, fqdn, &port);
-  con = taos_connect(fqdn, tsDefaultUser, tsDefaultPass, NULL, port);
+  con = taos_connect(fqdn, "root", "taosdata", NULL, port);
   if (con == NULL) {
     pError("failed to connect to DB, reason:%s", taos_errstr(con));
     exit(1);
@@ -184,7 +184,7 @@ void *syncTest(void *param) {
   uint16_t port;
 
   taosGetFqdnPortFromEp(tsFirst, fqdn, &port);
-  con = taos_connect(fqdn, tsDefaultUser, tsDefaultPass, NULL, port);
+  con = taos_connect(fqdn, "root", "taosdata", NULL, port);
   if (con == NULL) {
     pError("index:%d, failed to connect to DB, reason:%s", pInfo->threadIndex, taos_errstr(con));
     exit(1);
diff --git a/tests/test/c/insertPerTable.c b/tests/test/c/insertPerTable.c
index 00e12566867dc2745df629c7db9b3ecb707275d3..a5e2c4b966b99734c9137a11c8e410ad76d27ce4 100644
--- a/tests/test/c/insertPerTable.c
+++ b/tests/test/c/insertPerTable.c
@@ -74,7 +74,7 @@ void createDbAndTable() {
 
   taosGetFqdnPortFromEp(tsFirst, fqdn, &port);
 
-  con = taos_connect(fqdn, tsDefaultUser, tsDefaultPass, NULL, port);
+  con = taos_connect(fqdn, "root", "taosdata", NULL, port);
   if (con == NULL) {
     pError("failed to connect to DB, reason:%s", taos_errstr(con));
     exit(1);
@@ -222,7 +222,7 @@ void *syncTest(void *param) {
 
   taosGetFqdnPortFromEp(tsFirst, fqdn, &port);
 
-  con = taos_connect(fqdn, tsDefaultUser, tsDefaultPass, NULL, port);
+  con = taos_connect(fqdn, "root", "taosdata", NULL, port);
   if (con == NULL) {
     pError("index:%d, failed to connect to DB, reason:%s", pInfo->threadIndex, taos_errstr(con));
     exit(1);
diff --git a/tests/tsim/src/simExe.c b/tests/tsim/src/simExe.c
index f13e861907a8b4701b3556960b0797469f9d4bcc..aba9714f0acb38916be25640009aba54af9881c9 100644
--- a/tests/tsim/src/simExe.c
+++ b/tests/tsim/src/simExe.c
@@ -612,7 +612,7 @@ bool simCreateNativeConnect(SScript *script, char *user, char *pass) {
 }
 
 bool simCreateTaosdConnect(SScript *script, char *rest) {
-  char *user = tsDefaultUser;
+  char *user = TSDB_DEFAULT_USER;
   char *token;
   int tokenLen;
   rest = paGetToken(rest, &token, &tokenLen);
@@ -622,9 +622,9 @@ bool simCreateTaosdConnect(SScript *script, char *rest) {
   }
 
   if (simAsyncQuery) {
-    return simCreateRestFulConnect(script, user, tsDefaultPass);
+    return simCreateRestFulConnect(script, user, TSDB_DEFAULT_PASS);
   } else {
-    return simCreateNativeConnect(script, user, tsDefaultPass);
+    return simCreateNativeConnect(script, user, TSDB_DEFAULT_PASS);
   }
 }