diff --git a/packaging/cfg/taos.cfg b/packaging/cfg/taos.cfg
index d9a9ce32a2da534f973022fc2133e7fa97fe9b00..3f7ece8826c7dd90f47d6557e89acaeb93d23982 100644
--- a/packaging/cfg/taos.cfg
+++ b/packaging/cfg/taos.cfg
@@ -54,6 +54,9 @@
 # interval of system monitor 
 # monitorInterval       60
 
+# set socket type(UDP by default). if udpsocket is 0, TCP is applied for all connections
+# udpsocket             1
+
 # RPC re-try timer, millisecond
 # rpcTimer              300
 
diff --git a/src/client/src/tscSystem.c b/src/client/src/tscSystem.c
index 7428399210c4be1740ba07ee6332fae2da040b3f..ff0c1555ffc7e17ca36c7ea5aadb0a8d7090540c 100644
--- a/src/client/src/tscSystem.c
+++ b/src/client/src/tscSystem.c
@@ -118,7 +118,7 @@ void taos_init_imp() {
   rpcInit.sessionsPerChann = tsMaxVnodeConnections / tscNumOfThreads;
   rpcInit.idMgmt = TAOS_ID_FREE;
   rpcInit.noFree = 0;
-  rpcInit.connType = TAOS_CONN_UDP;
+  rpcInit.connType = TAOS_CONN_SOCKET_TYPE_C();
   rpcInit.qhandle = tscQhandle;
   pVnodeConn = taosOpenRpc(&rpcInit);
   if (pVnodeConn == NULL) {
@@ -139,7 +139,7 @@ void taos_init_imp() {
   rpcInit.sessionsPerChann = tsMaxMgmtConnections;
   rpcInit.idMgmt = TAOS_ID_FREE;
   rpcInit.noFree = 0;
-  rpcInit.connType = TAOS_CONN_UDP;
+  rpcInit.connType = TAOS_CONN_SOCKET_TYPE_C();
   rpcInit.qhandle = tscQhandle;
   pTscMgmtConn = taosOpenRpc(&rpcInit);
   if (pTscMgmtConn == NULL) {
diff --git a/src/inc/tglobalcfg.h b/src/inc/tglobalcfg.h
index cfc89997d3f171841761c98248a6e2c90bbb7f86..054317fcaeabe94a80d3ac2b730f1e27b5ccbf4d 100644
--- a/src/inc/tglobalcfg.h
+++ b/src/inc/tglobalcfg.h
@@ -132,6 +132,8 @@ extern int tsStreamCompRetryDelay;
 extern int     tsProjectExecInterval;
 extern int64_t tsMaxRetentWindow;
 
+extern int tsUDPSocket;
+
 extern char  tsHttpIp[];
 extern short tsHttpPort;
 extern int   tsHttpCacheSessions;
@@ -182,12 +184,12 @@ void tsSetTimeZone();
 void tsSetLocale();
 void tsInitGlobalConfig();
 
-#define TSDB_CFG_CTYPE_B_CONFIG 1   // can be configured from file
-#define TSDB_CFG_CTYPE_B_SHOW 2     // can displayed by "show configs" commands
-#define TSDB_CFG_CTYPE_B_LOG 4      // is a log type configuration
-#define TSDB_CFG_CTYPE_B_CLIENT 8   // can be displayed in the client log
-#define TSDB_CFG_CTYPE_B_OPTION 16  // can be configured by taos_options function
-#define TSDB_CFG_CTYPE_B_NOT_PRINT 32
+#define TSDB_CFG_CTYPE_B_CONFIG     1U   // can be configured from file
+#define TSDB_CFG_CTYPE_B_SHOW       2U   // can displayed by "show configs" commands
+#define TSDB_CFG_CTYPE_B_LOG        4U   // is a log type configuration
+#define TSDB_CFG_CTYPE_B_CLIENT     8U   // can be displayed in the client log
+#define TSDB_CFG_CTYPE_B_OPTION     16U  // can be configured by taos_options function
+#define TSDB_CFG_CTYPE_B_NOT_PRINT  32U
 
 #define TSDB_CFG_CSTATUS_NONE 0     // not configured
 #define TSDB_CFG_CSTATUS_DEFAULT 1  // use system default value
diff --git a/src/inc/trpc.h b/src/inc/trpc.h
index 70804903e32b369e49926db5451e1532765fa98f..0532f1c12990779962e154cb91f868f1e7e0c91a 100644
--- a/src/inc/trpc.h
+++ b/src/inc/trpc.h
@@ -34,6 +34,9 @@ extern "C" {
 #define TAOS_ID_FREE       1
 #define TAOS_ID_REALLOCATE 2
 
+#define TAOS_CONN_SOCKET_TYPE_S()  ((tsUDPSocket == 1)? TAOS_CONN_UDPS:TAOS_CONN_TCPS)
+#define TAOS_CONN_SOCKET_TYPE_C()  ((tsUDPSocket == 1)? TAOS_CONN_UDP:TAOS_CONN_TCPC)
+
 #define taosSendMsgToPeer(x, y, z) taosSendMsgToPeerH(x, y, z, NULL)
 #define taosOpenRpcChann(x, y, z) taosOpenRpcChannWithQ(x, y, z, NULL)
 #define taosBuildReqMsg(x, y) taosBuildReqMsgWithSize(x, y, 512)
diff --git a/src/system/src/mgmtShell.c b/src/system/src/mgmtShell.c
index 19f706f4a85eb62075035d223366144f97e3ec9f..9621af763b5feb527b9eee0fb4f88b077421e789 100644
--- a/src/system/src/mgmtShell.c
+++ b/src/system/src/mgmtShell.c
@@ -64,7 +64,7 @@ int mgmtInitShell() {
   rpcInit.numOfChanns = 1;
   rpcInit.sessionsPerChann = tsMaxShellConns;
   rpcInit.idMgmt = TAOS_ID_FREE;
-  rpcInit.connType = TAOS_CONN_UDPS;
+  rpcInit.connType = TAOS_CONN_SOCKET_TYPE_S();
   rpcInit.idleTime = tsShellActivityTimer * 2000;
   rpcInit.qhandle = mgmtQhandle;
   rpcInit.afp = mgmtRetriveUserAuthInfo;
diff --git a/src/system/src/vnodeShell.c b/src/system/src/vnodeShell.c
index c87c504dcba7abe414755dda371007f5f82faccb..66818766d97186bd62951f5f6635772a74da3ff0 100644
--- a/src/system/src/vnodeShell.c
+++ b/src/system/src/vnodeShell.c
@@ -127,7 +127,7 @@ int vnodeInitShell() {
   rpcInit.numOfChanns = TSDB_MAX_VNODES;
   rpcInit.sessionsPerChann = 16;
   rpcInit.idMgmt = TAOS_ID_FREE;
-  rpcInit.connType = TAOS_CONN_UDPS;
+  rpcInit.connType = TAOS_CONN_SOCKET_TYPE_S();
   rpcInit.idleTime = tsShellActivityTimer * 2000;
   rpcInit.qhandle = rpcQhandle[0];
   rpcInit.efp = vnodeSendVpeerCfgMsg;
diff --git a/src/util/src/tglobalcfg.c b/src/util/src/tglobalcfg.c
index 7bdd4df7e508c3786de39bae29f73bfbc2a3ca8b..f26732e68835197ec4411a5f18bf54ebc79eb078 100644
--- a/src/util/src/tglobalcfg.c
+++ b/src/util/src/tglobalcfg.c
@@ -122,6 +122,8 @@ int tsStreamCompRetryDelay = 10;                  // the stream computing delay
 int     tsProjectExecInterval = 10000;   // every 10sec, the projection will be executed once
 int64_t tsMaxRetentWindow = 24 * 3600L;  // maximum time window tolerance
 
+int tsUDPSocket = 1;               // use UDP by default, if tsUDPSocket equals to 0, all connection use TCP socket
+
 char  tsHttpIp[TSDB_IPv4ADDR_LEN] = "0.0.0.0";
 short tsHttpPort = 6020;                 // only tcp, range tcp[6020]
 // short tsNginxPort = 6060;             //only tcp, range tcp[6060]
@@ -494,7 +496,12 @@ void tsInitGlobalConfig() {
   tsInitConfigOption(cfg++, "defaultUser", tsDefaultUser, TSDB_CFG_VTYPE_STRING,
                      TSDB_CFG_CTYPE_B_CONFIG | TSDB_CFG_CTYPE_B_CLIENT, 0, 0, TSDB_USER_LEN, TSDB_CFG_UTYPE_NONE);
   tsInitConfigOption(cfg++, "defaultPass", tsDefaultPass, TSDB_CFG_VTYPE_STRING,
-                     TSDB_CFG_CTYPE_B_CONFIG | TSDB_CFG_CTYPE_B_CLIENT | TSDB_CFG_CTYPE_B_NOT_PRINT, 0, 0, TSDB_PASSWORD_LEN, TSDB_CFG_UTYPE_NONE);
+                     TSDB_CFG_CTYPE_B_CONFIG | TSDB_CFG_CTYPE_B_CLIENT | TSDB_CFG_CTYPE_B_NOT_PRINT, 0, 0,
+                     TSDB_PASSWORD_LEN, TSDB_CFG_UTYPE_NONE);
+
+  // socket type, udp by default
+  tsInitConfigOption(cfg++, "udpsocket", &tsUDPSocket, TSDB_CFG_VTYPE_INT,
+                     TSDB_CFG_CTYPE_B_CONFIG | TSDB_CFG_CTYPE_B_CLIENT | TSDB_CFG_CTYPE_B_SHOW, 0, 1, 1, TSDB_CFG_UTYPE_NONE);
 
   // locale & charset
   tsInitConfigOption(cfg++, "timezone", tsTimezone, TSDB_CFG_VTYPE_STRING,