diff --git a/src/common/inc/tglobal.h b/src/common/inc/tglobal.h
index 07d614d5ef26aca4ef083c3c73695fc44071ffa7..131c412575754a2fb322a7e52781a05a09087dde 100644
--- a/src/common/inc/tglobal.h
+++ b/src/common/inc/tglobal.h
@@ -45,6 +45,7 @@ extern int32_t  tsDnodeId;
 // common
 extern int      tsRpcTimer;
 extern int      tsRpcMaxTime;
+extern int      tsRpcForceTcp; // all commands go to tcp protocol if this is enabled
 extern int32_t  tsMaxConnections;
 extern int32_t  tsMaxShellConns;
 extern int32_t  tsShellActivityTimer;
diff --git a/src/common/src/tglobal.c b/src/common/src/tglobal.c
index 198d57b6b99badbf1d8d2c501bef20183b34a1d3..c93824ff350d85b726658e07208baad6c99bc06d 100644
--- a/src/common/src/tglobal.c
+++ b/src/common/src/tglobal.c
@@ -54,6 +54,7 @@ int32_t tsRpcTimer       = 300;
 int32_t tsRpcMaxTime     = 600;  // seconds;
 int32_t tsMaxShellConns  = 50000;
 int32_t tsMaxConnections = 5000;
+int32_t tsRpcForceTcp    = 0;  //disable this, means query, show command use udp protocol as default
 int32_t tsShellActivityTimer  = 3;  // second
 float   tsNumOfThreadsPerCore = 1.0f;
 int32_t tsNumOfCommitThreads = 4;
@@ -639,6 +640,16 @@ static void doInitGlobalConfig(void) {
   cfg.unitType = TAOS_CFG_UTYPE_SECOND;
   taosInitConfigOption(cfg);
 
+  cfg.option = "rpcForceTcp";
+  cfg.ptr = &tsRpcForceTcp;
+  cfg.valType = TAOS_CFG_VTYPE_INT32;
+  cfg.cfgType = TSDB_CFG_CTYPE_B_CONFIG | TSDB_CFG_CTYPE_B_CLIENT;
+  cfg.minValue = 0;
+  cfg.maxValue = 1;
+  cfg.ptrLength = 0;
+  cfg.unitType = TAOS_CFG_UTYPE_NONE;
+  taosInitConfigOption(cfg);
+
   cfg.option = "statusInterval";
   cfg.ptr = &tsStatusInterval;
   cfg.valType = TAOS_CFG_VTYPE_INT32;
diff --git a/src/rpc/src/rpcMain.c b/src/rpc/src/rpcMain.c
index 1f2e0fadb32b477577d3feb5138bcdc363f1d1f2..aac92ee99b6e236ca7c1728692cca46382a3ebf9 100644
--- a/src/rpc/src/rpcMain.c
+++ b/src/rpc/src/rpcMain.c
@@ -399,7 +399,7 @@ void rpcSendRequest(void *shandle, const SRpcEpSet *pEpSet, SRpcMsg *pMsg, int64
   pContext->oldInUse = pEpSet->inUse;
 
   pContext->connType = RPC_CONN_UDPC; 
-  if (contLen > tsRpcMaxUdpSize) pContext->connType = RPC_CONN_TCPC;
+  if (contLen > tsRpcMaxUdpSize || tsRpcForceTcp) pContext->connType = RPC_CONN_TCPC;
 
   // connection type is application specific. 
   // for TDengine, all the query, show commands shall have TCP connection