grpc++: process hang by synchronous stub call , set_deadline not valid? - c++

Question

i ran into a problem , pls help:
What version of gRPC and what language are you using?
libgrpc++.so.1.26.0
What operating system (Linux, Windows,...) and version?
centos7
What did you do?
my scenario is : I have a grpc server named A and, when I receive a grpc message, send the message to another grpc server named B directly;
my server A initial(CRpcNetServer class):
int CRpcNetServer::Initialize()
{
std::string listenAddr = "this is listen address";
ServerBuilder builder;
builder.AddListeningPort(listenAddr, grpc::InsecureServerCredentials());
//register
builder.RegisterService(&AService_); //protobuf definition A
builder.RegisterService(&BService_); //protobuf definition A
//
cq_ = builder.AddCompletionQueue();
server_ = builder.BuildAndStart();
new CallData(&AService_, &BService_, cq_.get(), CallData::S_TYPE_GRPC_MESSAGE);
//new CallData(&AService_, &BService_, cq_.get(), {other message type});
return ERROR_CODE_SUCCESS;
}
void CRpcNetServer::handleRpcs()
{
void *tag;
bool ok;
while (true)
{
if (GPR_UNLIKELY(!(cq_->Next(&tag, &ok))))
{
spdlog::error("handleRpcs||get next message failed, try again");
continue;
}
if (GPR_UNLIKELY(!ok))
{
spdlog::error("handleRpcs||get next message notok, try again");
continue;
}
static_cast<CallData *>(tag)->process();
}
}
when message arrived(CallData class):
void CallData::process()
{
if (status_ == CREATE)
{
status_ = PROCESS;
switch (s_type_)
{
case S_TYPE_GRPC_MESSAGE:
BService_->RequestOnMessage(&ctx_, &GrpcUpLinkMessage, &processGrpcUplinkResponse, cq_, cq_, this);
//case other message type
default:
break;
}
}
else if (status_ == PROCESS)
{
status_ = FINISH;
new CallData(AService_, BService_, cq_, this->s_type_);
switch (s_type_)
{
case S_TYPE_GRPC_UPLINK_MESSAGE:
{
Status ret = this->onGrpcUplinkMessage(gRPCUpLinkMessage, emptyResponse_);
processGrpcUplinkResponse.Finish(emptyResponse_, ret, this);
}
break;
default:
break;
}
}
else
{
GPR_ASSERT(status_ == FINISH);
delete this;
}
}
when i received a grpc message, send it to another grpc server directly:
//init grpc client:
CRpcNetClient::CRpcNetClient(){
std::shared_ptr<Channel> channel = grpc::CreateChannel({B server address}, grpc::InsecureChannelCredentials());
stub_ = BServerApi::SendToBDownlinkService::NewStub(channel);
}
//send
std::chrono::time_point<std::chrono::system_clock> deadline = std::chrono::system_clock::now() + std::chrono::milliseconds(100);
ClientContext context;
context.set_deadline(deadline);
std::time_t timestamp = getTimestamp();
Status status = stub_->publishMessage(&context, downLinkGroupRequest, &downLinkGroupResponse);
// process will hang here
std::chrono::time_pointstd::chrono::system_clock deadline = std::chrono::system_clock::now() + std::chrono::milliseconds(100);
I tried to set milliseconds to 1ms， it will return failed , so I think the param is worked, but while set it to 100, it will occurs some time (not inevitable).