Fix to #30390 Adding methods to get memory usage of server for the perchannel benchmark (#30435)

* Revert "Revert "Adding methods to get memory usage of server for the perchannel benchmark (#30390)" (#30433)"

This reverts commit 3fe438b55a.

* Made all variables used

src/proto/grpc/testing/benchmark_service.proto

@@ -41,4 +41,7 @@ service BenchmarkService {
   // Two-sided unbounded streaming between server to client
   // Both sides send the content of their own choice to the other
   rpc StreamingBothWays(stream SimpleRequest) returns (stream SimpleResponse);
+
+  //Get the memory usage of process before server is made
+  rpc GetBeforeSnapshot(SimpleRequest) returns (MemorySize); 
 }

src/proto/grpc/testing/messages.proto

@@ -268,3 +268,7 @@ message ClientConfigureRequest {
 
 // Response for updating a test client's configuration.
 message ClientConfigureResponse {}
+
+message MemorySize {
+  int64 rss = 1;
+}

test/core/memory_usage/BUILD

@@ -21,7 +21,22 @@ licenses(["notice"])
 grpc_cc_library(
     name = "memstats",
     testonly = 1,
+    srcs = [
+        "memstats.cc",
+        "memstats.h",
+    ],
     hdrs = ["memstats.h"],
+    external_deps = [
+        "absl/types:optional",
+    ],
+    tags = [
+        "bazel_only",
+        "no_mac",
+        "no_windows",
+    ],
+    deps = [
+        "//:gpr",
+    ],
 )
 
 grpc_cc_binary(

test/core/memory_usage/callback_client.cc

@@ -30,12 +30,14 @@
 
 #include "src/proto/grpc/testing/benchmark_service.grpc.pb.h"
 #include "src/proto/grpc/testing/messages.pb.h"
+#include "test/core/memory_usage/memstats.h"
 #include "test/core/util/test_config.h"
 
 ABSL_FLAG(std::string, target, "", "Target host:port");
 ABSL_FLAG(bool, secure, false, "Use SSL Credentials");
+ABSL_FLAG(int, server_pid, 99999, "Server's pid");
 
-void UnaryCall() {
+std::unique_ptr<grpc::testing::BenchmarkService::Stub> CreateStubForTest() {
   // Set the authentication mechanism.
   std::shared_ptr<grpc::ChannelCredentials> creds =
       grpc::InsecureChannelCredentials();
@@ -49,6 +51,12 @@ void UnaryCall() {
       CreateChannel(absl::GetFlag(FLAGS_target), creds);
   std::unique_ptr<grpc::testing::BenchmarkService::Stub> stub =
       grpc::testing::BenchmarkService::NewStub(channel);
+  return stub;
+}
+
+void UnaryCall() {
+  std::unique_ptr<grpc::testing::BenchmarkService::Stub> stub =
+      CreateStubForTest();
 
   // Start a call.
   struct CallParams {
@@ -67,6 +75,31 @@ void UnaryCall() {
                            });
 }
 
+// Get memory usage of server's process before the server is made
+long GetBeforeSnapshot() {
+  std::unique_ptr<grpc::testing::BenchmarkService::Stub> stub =
+      CreateStubForTest();
+
+  // Start a call.
+  struct CallParams {
+    grpc::ClientContext context;
+    grpc::testing::SimpleRequest request;
+    grpc::testing::MemorySize response;
+  };
+  CallParams* params = new CallParams();
+  stub->async()->GetBeforeSnapshot(
+      &params->context, &params->request, &params->response,
+      [params](const grpc::Status& status) {
+        if (status.ok()) {
+          gpr_log(GPR_INFO, "Before: %ld", params->response.rss());
+          gpr_log(GPR_INFO, "GetBeforeSnapshot succeeded.");
+        } else {
+          gpr_log(GPR_ERROR, "GetBeforeSnapshot failed.");
+        }
+      });
+  return params->response.rss();
+}
+
 int main(int argc, char** argv) {
   absl::ParseCommandLine(argc, argv);
   char* fake_argv[1];
@@ -79,7 +112,19 @@ int main(int argc, char** argv) {
   }
   gpr_log(GPR_INFO, "Client Target: %s", absl::GetFlag(FLAGS_target).c_str());
 
+  // Getting initial memory usage
+  long before_server_memory = GetBeforeSnapshot();
+  long before_client_memory = GetMemUsage();
+
   UnaryCall();
+
+  // Getting peak memory usage
+  long peak_server_memory = GetMemUsage(absl::GetFlag(FLAGS_server_pid));
+  long peak_client_memory = GetMemUsage();
+  gpr_log(GPR_INFO, "Before Server Mem: %ld", before_server_memory);
+  gpr_log(GPR_INFO, "Before Client Mem: %ld", before_client_memory);
+  gpr_log(GPR_INFO, "Peak Client Mem: %ld", peak_client_memory);
+  gpr_log(GPR_INFO, "Peak Server Mem: %ld", peak_server_memory);
   gpr_log(GPR_INFO, "Client Done");
   return 0;
 }

test/core/memory_usage/callback_server.cc

@@ -34,19 +34,37 @@
 
 #include "src/proto/grpc/testing/benchmark_service.grpc.pb.h"
 #include "src/proto/grpc/testing/messages.pb.h"
+#include "test/core/memory_usage/memstats.h"
 #include "test/core/util/test_config.h"
 
 class ServerCallbackImpl final
     : public grpc::testing::BenchmarkService::CallbackService {
+ public:
+  explicit ServerCallbackImpl(long before_server_memory)
+      : before_server_create(before_server_memory) {}
+
   grpc::ServerUnaryReactor* UnaryCall(
       grpc::CallbackServerContext* context,
       const grpc::testing::SimpleRequest* request,
       grpc::testing::SimpleResponse* response) override {
-    gpr_log(GPR_INFO, "RPC CALL RECEIVED");
+    gpr_log(GPR_INFO, "UnaryCall RPC CALL RECEIVED");
     auto* reactor = context->DefaultReactor();
     reactor->Finish(grpc::Status::OK);
     return reactor;
   }
+  grpc::ServerUnaryReactor* GetBeforeSnapshot(
+      grpc::CallbackServerContext* context,
+      const grpc::testing::SimpleRequest* request,
+      grpc::testing::MemorySize* response) override {
+    gpr_log(GPR_INFO, "BeforeSnapshot RPC CALL RECEIVED");
+    response->set_rss(before_server_create);
+    auto* reactor = context->DefaultReactor();
+    reactor->Finish(grpc::Status::OK);
+    return reactor;
+  }
+
+ private:
+  long before_server_create;
 };
 
 /* We have some sort of deadlock, so let's not exit gracefully for now.
@@ -71,8 +89,12 @@ int main(int argc, char** argv) {
   }
   gpr_log(GPR_INFO, "Server port: %s", server_address.c_str());
 
-  ServerCallbackImpl callback_server;
+  // Get initial process memory usage before creating server
+  long before_server_create = GetMemUsage();
+  gpr_log(GPR_INFO, "Server Before Mem: %ld", before_server_create);
+  ServerCallbackImpl callback_server(before_server_create);
   grpc::ServerBuilder builder;
+
   // Set the authentication mechanism.
   std::shared_ptr<grpc::ServerCredentials> creds =
       grpc::InsecureServerCredentials();

test/core/memory_usage/memory_usage_test.cc

@@ -62,6 +62,7 @@ class Subprocess {
     process_ = gpr_subprocess_create(args_c.size(), args_c.data());
   }
 
+  int GetPID() { return gpr_subprocess_get_process_id(process_); }
   int Join() { return gpr_subprocess_join(process_); }
   void Interrupt() { gpr_subprocess_interrupt(process_); }
 
@@ -127,7 +128,8 @@ int RunChannelBenchmark(char* root) {
   std::vector<std::string> client_flags = {
       absl::StrCat(root, "/memory_usage_callback_client",
                    gpr_subprocess_binary_extension()),
-      "--target", grpc_core::JoinHostPort("127.0.0.1", port), "--nosecure"};
+      "--target", grpc_core::JoinHostPort("127.0.0.1", port), "--nosecure",
+      absl::StrCat("--server_pid=", svr.GetPID())};
   Subprocess cli(client_flags);
   /* wait for completion */
   if ((status = cli.Join()) != 0) {

test/core/memory_usage/memstats.cc

@@ -0,0 +1,56 @@
+// Copyright 2022 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 "test/core/memory_usage/memstats.h"
+
+#include <unistd.h>
+
+#include <fstream>
+#include <string>
+
+#include "absl/strings/str_cat.h"
+
+#include <grpc/support/log.h>
+
+long GetMemUsage(absl::optional<int> pid) {
+  // Default is getting memory usage for self (calling process)
+  std::string path = "/proc/self/stat";
+  if (pid != absl::nullopt) {
+    path = absl::StrCat("/proc/", pid.value(), "/stat");
+  }
+  std::ifstream stat_stream(path, std::ios_base::in);
+
+  double resident_set = 0.0;
+  // Temporary variables for irrelevant leading entries in stats
+  std::string temp_pid, comm, state, ppid, pgrp, session, tty_nr;
+  std::string tpgid, flags, minflt, cminflt, majflt, cmajflt;
+  std::string utime, stime, cutime, cstime, priority, nice;
+  std::string O, itrealvalue, starttime, vsize;
+
+  // Get rss to find memory usage
+  long rss;
+  stat_stream >> temp_pid >> comm >> state >> ppid >> pgrp >> session >>
+      tty_nr >> tpgid >> flags >> minflt >> cminflt >> majflt >> cmajflt >>
+      utime >> stime >> cutime >> cstime >> priority >> nice >> O >>
+      itrealvalue >> starttime >> vsize >> rss;
+  stat_stream.close();
+
+  // pid does not connect to an existing process
+  GPR_ASSERT(!state.empty());
+
+  // Calculations in case x86-64 is configured to use 2MB pages
+  long page_size_kb = sysconf(_SC_PAGE_SIZE) / 1024;
+  resident_set = rss * page_size_kb;
+  return resident_set;
+}

test/core/memory_usage/memstats.h

@@ -15,18 +15,17 @@
 #ifndef TEST_H
 #define TEST_H
 
-#include <stdlib.h>
-#include <sys/resource.h>
+#include "absl/types/optional.h"
 
 // IWYU pragma: no_include <bits/types/struct_rusage.h>
 
+// Get the memory usage of either the calling process or another process using
+// the pid
+long GetMemUsage(absl::optional<int> pid = absl::nullopt);
+
 struct MemStats {
   long rss;  // Resident set size, in kb
-  static MemStats Snapshot() {
-    struct rusage usage;
-    if (0 != getrusage(RUSAGE_SELF, &usage)) abort();
-    return MemStats{usage.ru_maxrss};
-  }
+  static MemStats Snapshot() { return MemStats{GetMemUsage()}; }
 };
 
 #endif

test/core/util/subprocess.h

@@ -32,5 +32,6 @@ void gpr_subprocess_destroy(gpr_subprocess* p);
 /** returns exit status; can be called at most once */
 int gpr_subprocess_join(gpr_subprocess* p);
 void gpr_subprocess_interrupt(gpr_subprocess* p);
+int gpr_subprocess_get_process_id(gpr_subprocess* p);
 
 #endif /* GRPC_TEST_CORE_UTIL_SUBPROCESS_H */

test/core/util/subprocess_posix.cc

@@ -92,4 +92,6 @@ void gpr_subprocess_interrupt(gpr_subprocess* p) {
   }
 }
 
+int gpr_subprocess_get_process_id(gpr_subprocess* p) { return p->pid; }
+
 #endif /* GPR_POSIX_SUBPROCESS */

test/core/util/subprocess_windows.cc

@@ -124,4 +124,8 @@ void gpr_subprocess_interrupt(gpr_subprocess* p) {
   return;
 }
 
+int gpr_subprocess_get_process_id(gpr_subprocess* p) {
+  return p->pi.dwProcessId;
+}
+
 #endif /* GPR_WINDOWS_SUBPROCESS */