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/*
*
* Copyright 2016 gRPC authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
#include <memory>
#include <mutex>
#include <thread>
#include <grpc/grpc.h>
#include <grpc/support/log.h>
#include <grpc/support/time.h>
#include <grpcpp/channel.h>
#include <grpcpp/client_context.h>
#include <grpcpp/create_channel.h>
#include <grpcpp/server.h>
#include <grpcpp/server_builder.h>
#include "src/proto/grpc/testing/echo.grpc.pb.h"
#include "test/core/util/port.h"
#include "test/core/util/test_config.h"
#include "test/cpp/end2end/test_service_impl.h"
#include <gtest/gtest.h>
using grpc::testing::EchoRequest;
using grpc::testing::EchoResponse;
using std::chrono::system_clock;
namespace grpc {
namespace testing {
namespace {
// Subclass of TestServiceImpl that increments a request counter for
// every call to the Echo RPC.
class MyTestServiceImpl : public TestServiceImpl {
public:
MyTestServiceImpl() : request_count_(0) {}
Status Echo(ServerContext* context, const EchoRequest* request,
EchoResponse* response) override {
{
std::unique_lock<std::mutex> lock(mu_);
++request_count_;
}
return TestServiceImpl::Echo(context, request, response);
}
int request_count() {
std::unique_lock<std::mutex> lock(mu_);
return request_count_;
}
private:
std::mutex mu_;
int request_count_;
};
class RoundRobinEnd2endTest : public ::testing::Test {
protected:
RoundRobinEnd2endTest() : server_host_("localhost") {}
void StartServers(size_t num_servers,
std::vector<int> ports = std::vector<int>()) {
for (size_t i = 0; i < num_servers; ++i) {
int port = 0;
if (ports.size() == num_servers) port = ports[i];
servers_.emplace_back(new ServerData(server_host_, port));
}
}
void TearDown() override {
for (size_t i = 0; i < servers_.size(); ++i) {
servers_[i]->Shutdown();
}
}
void ResetStub(bool round_robin) {
ChannelArguments args;
if (round_robin) args.SetLoadBalancingPolicyName("round_robin");
std::ostringstream uri;
uri << "ipv4:///";
for (size_t i = 0; i < servers_.size() - 1; ++i) {
uri << "127.0.0.1:" << servers_[i]->port_ << ",";
}
uri << "127.0.0.1:" << servers_[servers_.size() - 1]->port_;
channel_ =
CreateCustomChannel(uri.str(), InsecureChannelCredentials(), args);
stub_ = grpc::testing::EchoTestService::NewStub(channel_);
}
void SendRpc(int num_rpcs, bool expect_ok = true) {
EchoRequest request;
EchoResponse response;
request.set_message("Live long and prosper.");
for (int i = 0; i < num_rpcs; i++) {
ClientContext context;
Status status = stub_->Echo(&context, request, &response);
if (expect_ok) {
EXPECT_TRUE(status.ok());
EXPECT_EQ(response.message(), request.message());
} else {
EXPECT_FALSE(status.ok());
}
}
}
struct ServerData {
int port_;
std::unique_ptr<Server> server_;
MyTestServiceImpl service_;
explicit ServerData(const grpc::string& server_host, int port = 0) {
port_ = port > 0 ? port : grpc_pick_unused_port_or_die();
gpr_log(GPR_INFO, "starting server on port %d", port_);
std::ostringstream server_address;
server_address << server_host << ":" << port_;
ServerBuilder builder;
builder.AddListeningPort(server_address.str(),
InsecureServerCredentials());
builder.RegisterService(&service_);
server_ = builder.BuildAndStart();
gpr_log(GPR_INFO, "server startup complete");
}
void Shutdown() { server_->Shutdown(); }
};
const grpc::string server_host_;
std::shared_ptr<Channel> channel_;
std::unique_ptr<grpc::testing::EchoTestService::Stub> stub_;
std::vector<std::unique_ptr<ServerData>> servers_;
};
TEST_F(RoundRobinEnd2endTest, PickFirst) {
// Start servers and send one RPC per server.
const int kNumServers = 3;
StartServers(kNumServers);
ResetStub(false /* round_robin */);
SendRpc(kNumServers);
// All requests should have gone to a single server.
bool found = false;
for (size_t i = 0; i < servers_.size(); ++i) {
const int request_count = servers_[i]->service_.request_count();
if (request_count == kNumServers) {
found = true;
} else {
EXPECT_EQ(0, request_count);
}
}
EXPECT_TRUE(found);
// Check LB policy name for the channel.
EXPECT_EQ("pick_first", channel_->GetLoadBalancingPolicyName());
}
TEST_F(RoundRobinEnd2endTest, RoundRobin) {
// Start servers and send one RPC per server.
const int kNumServers = 3;
StartServers(kNumServers);
ResetStub(true /* round_robin */);
// Send one RPC per backend and make sure they are used in order.
// Note: This relies on the fact that the subchannels are reported in
// state READY in the order in which the addresses are specified,
// which is only true because the backends are all local.
for (size_t i = 0; i < servers_.size(); ++i) {
SendRpc(1);
EXPECT_EQ(1, servers_[i]->service_.request_count()) << "for backend #" << i;
}
// Check LB policy name for the channel.
EXPECT_EQ("round_robin", channel_->GetLoadBalancingPolicyName());
}
TEST_F(RoundRobinEnd2endTest, RoundRobinReconnect) {
// Start servers and send one RPC per server.
const int kNumServers = 1;
std::vector<int> ports;
ports.push_back(grpc_pick_unused_port_or_die());
StartServers(kNumServers, ports);
ResetStub(true /* round_robin */);
// Send one RPC per backend and make sure they are used in order.
// Note: This relies on the fact that the subchannels are reported in
// state READY in the order in which the addresses are specified,
// which is only true because the backends are all local.
for (size_t i = 0; i < servers_.size(); ++i) {
SendRpc(1);
EXPECT_EQ(1, servers_[i]->service_.request_count()) << "for backend #" << i;
}
// Check LB policy name for the channel.
EXPECT_EQ("round_robin", channel_->GetLoadBalancingPolicyName());
// Kill all servers
for (size_t i = 0; i < servers_.size(); ++i) {
servers_[i]->Shutdown();
}
// Client request should fail.
SendRpc(1, false);
// Bring servers back up on the same port (we aren't recreating the channel).
StartServers(kNumServers, ports);
// Client request should succeed.
SendRpc(1);
}
} // namespace
} // namespace testing
} // namespace grpc
int main(int argc, char** argv) {
grpc_test_init(argc, argv);
::testing::InitGoogleTest(&argc, argv);
return RUN_ALL_TESTS();
}
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