[TD-6663]<feature> support rpcForceTcp

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;

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;

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