feat: add a service option to disable check eovercrowded on server side

src/brpc/policy/baidu_rpc_protocol.cpp

@@ -472,13 +472,13 @@ void ProcessRpcRequest(InputMessageBase* msg_base) {
             cntl->SetFailed(ELOGOFF, "Server is stopping");
             break;
         }
-
-        if (socket->is_overcrowded()) {
+        
+        if (socket->is_overcrowded() && !server->options().ignore_eovercrowded) {
             cntl->SetFailed(EOVERCROWDED, "Connection to %s is overcrowded",
                             butil::endpoint2str(socket->remote_side()).c_str());
             break;
         }
-        
+
         if (!server_accessor.AddConcurrency(cntl.get())) {
             cntl->SetFailed(
                 ELIMIT, "Reached server's max_concurrency=%d",

src/brpc/policy/http_rpc_protocol.cpp

@@ -1495,7 +1495,7 @@ void ProcessHttpRequest(InputMessageBase *msg) {
     // NOTE: accesses to builtin services are not counted as part of
     // concurrency, therefore are not limited by ServerOptions.max_concurrency.
     if (!sp->is_builtin_service && !sp->params.is_tabbed) {
-        if (socket->is_overcrowded()) {
+        if (socket->is_overcrowded() && !server->options().ignore_eovercrowded) {
             cntl->SetFailed(EOVERCROWDED, "Connection to %s is overcrowded",
                             butil::endpoint2str(socket->remote_side()).c_str());
             return;

src/brpc/policy/hulu_pbrpc_protocol.cpp

@@ -422,7 +422,7 @@ void ProcessHuluRequest(InputMessageBase* msg_base) {
             break;
         }
 
-        if (socket->is_overcrowded()) {
+        if (socket->is_overcrowded() && !server->options().ignore_eovercrowded) {
             cntl->SetFailed(EOVERCROWDED, "Connection to %s is overcrowded",
                             butil::endpoint2str(socket->remote_side()).c_str());
             break;

src/brpc/policy/nshead_protocol.cpp

@@ -301,7 +301,7 @@ void ProcessNsheadRequest(InputMessageBase* msg_base) {
             cntl->SetFailed(ELOGOFF, "Server is stopping");
             break;
         }
-        if (socket->is_overcrowded()) {
+        if (socket->is_overcrowded() && !server->options().ignore_eovercrowded) {
             cntl->SetFailed(EOVERCROWDED, "Connection to %s is overcrowded",
                             butil::endpoint2str(socket->remote_side()).c_str());
             break;

src/brpc/policy/sofa_pbrpc_protocol.cpp

@@ -381,7 +381,7 @@ void ProcessSofaRequest(InputMessageBase* msg_base) {
             break;
         }
 
-        if (socket->is_overcrowded()) {
+        if (socket->is_overcrowded() && !server->options().ignore_eovercrowded) {
             cntl->SetFailed(EOVERCROWDED, "Connection to %s is overcrowded",
                             butil::endpoint2str(socket->remote_side()).c_str());
             break;

src/brpc/policy/thrift_protocol.cpp

@@ -530,7 +530,7 @@ void ProcessThriftRequest(InputMessageBase* msg_base) {
     if (!server->IsRunning()) {
         return cntl->SetFailed(ELOGOFF, "Server is stopping");
     }
-    if (socket->is_overcrowded()) {
+    if (socket->is_overcrowded() && !server->options().ignore_eovercrowded) {
         return cntl->SetFailed(EOVERCROWDED, "Connection to %s is overcrowded",
                 butil::endpoint2str(socket->remote_side()).c_str());
     }

src/brpc/server.cpp

@@ -152,7 +152,8 @@ ServerOptions::ServerOptions()
     , rtmp_service(NULL)
     , redis_service(NULL)
     , bthread_tag(BTHREAD_TAG_INVALID)
-    , rpc_pb_message_factory(new DefaultRpcPBMessageFactory()) {
+    , rpc_pb_message_factory(new DefaultRpcPBMessageFactory())
+    , ignore_eovercrowded(false) {
     if (s_ncore > 0) {
         num_threads = s_ncore + 1;
     }

src/brpc/server.h

@@ -287,6 +287,11 @@ struct ServerOptions {
     // Owned by Server and deleted in server's destructor.
     RpcPBMessageFactory* rpc_pb_message_factory;
 
+    // Ignore eovercrowded error on server side, i.e. , if eovercrowded is reported when server is processing a rpc request,
+    // server will keep processing this request, it is expected to be used by some light-weight control-frame rpcs.
+    // [CUATION] You should not enabling this option if your rpc is heavy-loaded.
+    bool ignore_eovercrowded;
+
 private:
     // SSLOptions is large and not often used, allocate it on heap to
     // prevent ServerOptions from being bloated in most cases.