Select a random unused port for the RPC benchmark

Currently, the benchmark uses a hard-coded port. This causes issues when running multiple instances of the benchmark concurrently, as they all use the same port.

PiperOrigin-RevId: 752333959
Change-Id: I3f7642a6dcd25fd0e5f1b4fe15f9d056ecf8b198

Author: andreas-abel

fleetbench/rpc/BUILD

@@ -154,6 +154,7 @@ cc_library(
         "@com_github_grpc_grpc//:grpc++",
         "@com_google_absl//absl/flags:flag",
         "@com_google_absl//absl/log",
+        "@com_google_absl//absl/log:check",
         "@com_google_absl//absl/random",
         "@com_google_absl//absl/status",
         "@com_google_absl//absl/strings",

fleetbench/rpc/rpcperf.cc

@@ -20,6 +20,7 @@
 #include <vector>
 
 #include "absl/flags/flag.h"
+#include "absl/log/check.h"
 #include "absl/log/log.h"
 #include "absl/random/random.h"
 #include "absl/status/status.h"
@@ -94,15 +95,20 @@ std::string HostPortString(absl::string_view host, uint16_t port) {
 std::unique_ptr<GRPCServer> CreateAndStartServer(
     std::vector<std::string> ports, int32_t workers, bool compress,
     bool checksum, std::string logstats_output_path,
-    std::string resp_delay_us_dist, absl::string_view program) {
+    std::string resp_delay_us_dist, absl::string_view program,
+    std::vector<int>* selected_ports) {
+  CHECK(selected_ports == nullptr || selected_ports->size() == ports.size())
+      << "selected_ports must be nullptr, or have the same size as ports";
+
   // First parse the distributions.
   fleetbench::rpc::DistributionArgs resp_delay_us_dist_args =
       ParseDistributionArgs(resp_delay_us_dist, "<Response delay distribution>",
                             0);
 
   grpc::ServerBuilder builder;
 
-  for (const auto& port_str : ports) {
+  for (int i = 0; i < ports.size(); ++i) {
+    std::string& port_str = ports[i];
     if (port_str.empty()) {
       continue;
     }
@@ -112,8 +118,9 @@ std::unique_ptr<GRPCServer> CreateAndStartServer(
       continue;
     }
 
+    int* selected_port = selected_ports ? &(*selected_ports)[i] : nullptr;
     builder.AddListeningPort(HostPortString("::", port),
-                             grpc::InsecureServerCredentials());
+                             grpc::InsecureServerCredentials(), selected_port);
   }
 
   fleetbench::rpc::GRPCServerOptions opts;

fleetbench/rpc/rpcperf.h

@@ -30,7 +30,8 @@ namespace fleetbench::rpc {
 std::unique_ptr<GRPCServer> CreateAndStartServer(
     std::vector<std::string> ports, int32_t workers, bool compress,
     bool checksum, std::string logstats_output_path,
-    std::string resp_delay_us_dist, absl::string_view program);
+    std::string resp_delay_us_dist, absl::string_view program,
+    std::vector<int>* selected_ports = nullptr);
 
 std::unique_ptr<GRPCClient> CreateAndStartClient(
     int32_t max_outstanding_rpcs, bool compress, bool checksum,

fleetbench/rpc/rpcperf_benchmark.cc

@@ -15,6 +15,7 @@
 #include <memory>
 #include <string>
 #include <utility>
+#include <vector>
 
 #include "absl/log/check.h"
 #include "absl/strings/str_cat.h"
@@ -37,18 +38,26 @@ void BM_Rpc(benchmark::State &state, absl::string_view program) {
   CHECK(fleetbench::rpc::kPrograms->count(program))
       << "Invalid program name \"" << program << "\" provided to benchmark";
 
+  // Requesting port 0 causes the OS to select a random unused port.
+  std::vector<std::string> ports = {"0"};
+  std::vector<int> selected_ports(ports.size());
+
   std::unique_ptr<fleetbench::rpc::GRPCServer> server =
       fleetbench::rpc::CreateAndStartServer(
-          /*ports=*/{"10000"}, /*workers=*/1, /*compress=*/false,
+          /*ports=*/ports, /*workers=*/1, /*compress=*/false,
           /*checksum=*/false, /*logstats_output_path=*/"",
-          /*resp_delay_us_dist=*/"", /*program=*/program);
+          /*resp_delay_us_dist=*/"", /*program=*/program,
+          /*selected_ports=*/&selected_ports);
+
+  std::vector<std::string> peers = {
+      absl::StrCat("localhost:", selected_ports[0])};
 
   absl::Mutex keep_running_mtx;
   std::unique_ptr<fleetbench::rpc::GRPCClient> client =
       fleetbench::rpc::CreateAndStartClient(
           /*max_outstanding_rpcs=*/1, /*compress=*/false,
           /*checksum=*/false, /*skip_loopback=*/false,
-          /*peers=*/{"localhost:10000"}, /*max_peers=*/-1,
+          /*peers=*/peers, /*max_peers=*/-1,
           /*connections_per_peer=*/1, /*logstats_output_path=*/"",
           /*req_delay_us_dist=*/"", /*program=*/program,
           /*keep_running=*/[&state, &keep_running_mtx]() {