Simplify QPS Metrics collection

test/cpp/interop/stress_interop_client.cc

@@ -84,49 +84,37 @@ StressTestInteropClient::StressTestInteropClient(
     int test_id, const grpc::string& server_address,
     std::shared_ptr<Channel> channel,
     const WeightedRandomTestSelector& test_selector, long test_duration_secs,
-    long sleep_duration_ms, long metrics_collection_interval_secs)
+    long sleep_duration_ms)
     : test_id_(test_id),
       server_address_(server_address),
       channel_(channel),
       interop_client_(new InteropClient(channel, false)),
       test_selector_(test_selector),
       test_duration_secs_(test_duration_secs),
-      sleep_duration_ms_(sleep_duration_ms),
-      metrics_collection_interval_secs_(metrics_collection_interval_secs) {}
+      sleep_duration_ms_(sleep_duration_ms) {}
 
-void StressTestInteropClient::MainLoop(std::shared_ptr<Gauge> qps_gauge) {
+void StressTestInteropClient::MainLoop(std::shared_ptr<QpsGauge> qps_gauge) {
   gpr_log(GPR_INFO, "Running test %d. ServerAddr: %s", test_id_,
           server_address_.c_str());
 
-  gpr_timespec test_end_time =
-      gpr_time_add(gpr_now(GPR_CLOCK_REALTIME),
-                   gpr_time_from_seconds(test_duration_secs_, GPR_TIMESPAN));
+  gpr_timespec test_end_time;
+  if (test_duration_secs_ < 0) {
+    test_end_time = gpr_inf_future(GPR_CLOCK_REALTIME);
+  } else {
+    test_end_time =
+        gpr_time_add(gpr_now(GPR_CLOCK_REALTIME),
+                     gpr_time_from_seconds(test_duration_secs_, GPR_TIMESPAN));
+  }
 
-  gpr_timespec current_time = gpr_now(GPR_CLOCK_REALTIME);
-  gpr_timespec next_stat_collection_time = current_time;
-  gpr_timespec collection_interval =
-      gpr_time_from_seconds(metrics_collection_interval_secs_, GPR_TIMESPAN);
-  long num_calls_per_interval = 0;
+  qps_gauge->Reset();
 
-  while (test_duration_secs_ < 0 ||
-         gpr_time_cmp(gpr_now(GPR_CLOCK_REALTIME), test_end_time) < 0) {
+  while (gpr_time_cmp(gpr_now(GPR_CLOCK_REALTIME), test_end_time) < 0) {
     // Select the test case to execute based on the weights and execute it
     TestCaseType test_case = test_selector_.GetNextTest();
     gpr_log(GPR_DEBUG, "%d - Executing the test case %d", test_id_, test_case);
     RunTest(test_case);
 
-    num_calls_per_interval++;
-
-    // See if its time to collect stats yet
-    current_time = gpr_now(GPR_CLOCK_REALTIME);
-    if (gpr_time_cmp(next_stat_collection_time, current_time) < 0) {
-      qps_gauge->Set(num_calls_per_interval /
-                     metrics_collection_interval_secs_);
-
-      num_calls_per_interval = 0;
-      next_stat_collection_time =
-          gpr_time_add(current_time, collection_interval);
-    }
+    qps_gauge->Incr();
 
     // Sleep between successive calls if needed
     if (sleep_duration_ms_ > 0) {

test/cpp/interop/stress_interop_client.h

@@ -87,12 +87,11 @@ class StressTestInteropClient {
   StressTestInteropClient(int test_id, const grpc::string& server_address,
                           std::shared_ptr<Channel> channel,
                           const WeightedRandomTestSelector& test_selector,
-                          long test_duration_secs, long sleep_duration_ms,
-                          long metrics_collection_interval_secs);
+                          long test_duration_secs, long sleep_duration_ms);
 
   // The main function. Use this as the thread entry point.
-  // qps_gauge is the Gauge to record the requests per second metric
-  void MainLoop(std::shared_ptr<Gauge> qps_gauge);
+  // qps_gauge is the QpsGauge to record the requests per second metric
+  void MainLoop(std::shared_ptr<QpsGauge> qps_gauge);
 
  private:
   void RunTest(TestCaseType test_case);
@@ -104,7 +103,6 @@ class StressTestInteropClient {
   const WeightedRandomTestSelector& test_selector_;
   long test_duration_secs_;
   long sleep_duration_ms_;
-  long metrics_collection_interval_secs_;
 };
 
 }  // namespace testing

test/cpp/interop/stress_test.cc

@@ -56,9 +56,6 @@ extern void gpr_default_log(gpr_log_func_args* args);
 
 DEFINE_int32(metrics_port, 8081, "The metrics server port.");
 
-DEFINE_int32(metrics_collection_interval_secs, 5,
-             "How often (in seconds) should metrics be recorded.");
-
 DEFINE_int32(sleep_duration_ms, 0,
              "The duration (in millisec) between two"
              " consecutive test calls (per server) issued by the server.");
@@ -275,19 +272,19 @@ int main(int argc, char** argv) {
            stub_idx++) {
         StressTestInteropClient* client = new StressTestInteropClient(
             ++thread_idx, *it, channel, test_selector, FLAGS_test_duration_secs,
-            FLAGS_sleep_duration_ms, FLAGS_metrics_collection_interval_secs);
+            FLAGS_sleep_duration_ms);
 
-        bool is_already_created;
-        // Gauge name
+        bool is_already_created = false;
+        // QpsGauge name
         std::snprintf(buffer, sizeof(buffer),
                       "/stress_test/server_%d/channel_%d/stub_%d/qps",
                       server_idx, channel_idx, stub_idx);
 
         test_threads.emplace_back(grpc::thread(
             &StressTestInteropClient::MainLoop, client,
-            metrics_service.CreateGauge(buffer, &is_already_created)));
+            metrics_service.CreateQpsGauge(buffer, &is_already_created)));
 
-        // The Gauge should not have been already created
+        // The QpsGauge should not have been already created
         GPR_ASSERT(!is_already_created);
       }
     }

test/cpp/util/metrics_server.cc

@@ -42,16 +42,26 @@
 namespace grpc {
 namespace testing {
 
-Gauge::Gauge(long initial_val) : val_(initial_val) {}
+QpsGauge::QpsGauge()
+    : start_time_(gpr_now(GPR_CLOCK_REALTIME)), num_queries_(0) {}
 
-void Gauge::Set(long new_val) {
-  std::lock_guard<std::mutex> lock(val_mu_);
-  val_ = new_val;
+void QpsGauge::Reset() {
+  std::lock_guard<std::mutex> lock(num_queries_mu_);
+  num_queries_ = 0;
+  start_time_ = gpr_now(GPR_CLOCK_REALTIME);
 }
 
-long Gauge::Get() {
-  std::lock_guard<std::mutex> lock(val_mu_);
-  return val_;
+void QpsGauge::Incr() {
+  std::lock_guard<std::mutex> lock(num_queries_mu_);
+  num_queries_++;
+}
+
+long QpsGauge::Get() {
+  std::lock_guard<std::mutex> lock(num_queries_mu_);
+  gpr_timespec time_diff =
+      gpr_time_sub(gpr_now(GPR_CLOCK_REALTIME), start_time_);
+  long duration_secs = time_diff.tv_sec > 0 ? time_diff.tv_sec : 1;
+  return num_queries_ / duration_secs;
 }
 
 grpc::Status MetricsServiceImpl::GetAllGauges(
@@ -60,7 +70,7 @@ grpc::Status MetricsServiceImpl::GetAllGauges(
   gpr_log(GPR_DEBUG, "GetAllGauges called");
 
   std::lock_guard<std::mutex> lock(mu_);
-  for (auto it = gauges_.begin(); it != gauges_.end(); it++) {
+  for (auto it = qps_gauges_.begin(); it != qps_gauges_.end(); it++) {
     GaugeResponse resp;
     resp.set_name(it->first);                // Gauge name
     resp.set_long_value(it->second->Get());  // Gauge value
@@ -75,8 +85,8 @@ grpc::Status MetricsServiceImpl::GetGauge(ServerContext* context,
                                           GaugeResponse* response) {
   std::lock_guard<std::mutex> lock(mu_);
 
-  const auto it = gauges_.find(request->name());
-  if (it != gauges_.end()) {
+  const auto it = qps_gauges_.find(request->name());
+  if (it != qps_gauges_.end()) {
     response->set_name(it->first);
     response->set_long_value(it->second->Get());
   }
@@ -84,16 +94,17 @@ grpc::Status MetricsServiceImpl::GetGauge(ServerContext* context,
   return Status::OK;
 }
 
-std::shared_ptr<Gauge> MetricsServiceImpl::CreateGauge(const grpc::string& name,
-                                                       bool* already_present) {
+std::shared_ptr<QpsGauge> MetricsServiceImpl::CreateQpsGauge(
+    const grpc::string& name, bool* already_present) {
   std::lock_guard<std::mutex> lock(mu_);
 
-  std::shared_ptr<Gauge> gauge(new Gauge(0));
-  const auto p = gauges_.emplace(name, gauge);
+  std::shared_ptr<QpsGauge> qps_gauge(new QpsGauge());
+  const auto p = qps_gauges_.emplace(name, qps_gauge);
 
-  // p.first is an iterator pointing to <name, shared_ptr<Gauge>> pair. p.second
-  // is a boolean which is set to 'true' if the Gauge is inserted in the guages_
-  // map and 'false' if it is already present in the map
+  // p.first is an iterator pointing to <name, shared_ptr<QpsGauge>> pair.
+  // p.second is a boolean which is set to 'true' if the QpsGauge is
+  // successfully inserted in the guages_ map and 'false' if it is already
+  // present in the map
   *already_present = !p.second;
   return p.first->second;
 }

test/cpp/util/metrics_server.h

@@ -36,6 +36,7 @@
 #include <map>
 #include <mutex>
 
+#include "grpc/support/time.h"
 #include "src/proto/grpc/testing/metrics.grpc.pb.h"
 #include "src/proto/grpc/testing/metrics.pb.h"
 
@@ -48,10 +49,13 @@
  * Example:
  *    MetricsServiceImpl metricsImpl;
  *    ..
- *    // Create Gauge(s). Note: Gauges can be created even after calling
+ *    // Create QpsGauge(s). Note: QpsGauges can be created even after calling
  *    // 'StartServer'.
- *    Gauge gauge1 = metricsImpl.CreateGauge("foo",is_present);
- *    // gauge1 can now be used anywhere in the program to set values.
+ *    QpsGauge qps_gauge1 = metricsImpl.CreateQpsGauge("foo", is_present);
+ *    // qps_gauge1 can now be used anywhere in the program by first making a
+ *    // one-time call qps_gauge1.Reset() and then calling qps_gauge1.Incr()
+ *    // every time to increment a query counter
+ *
  *    ...
  *    // Create the metrics server
  *    std::unique_ptr<grpc::Server> server = metricsImpl.StartServer(port);
@@ -60,17 +64,24 @@
 namespace grpc {
 namespace testing {
 
-// TODO(sreek): Add support for other types of Gauges like Double, String in
-// future
-class Gauge {
+class QpsGauge {
  public:
-  Gauge(long initial_val);
-  void Set(long new_val);
+  QpsGauge();
+
+  // Initialize the internal timer and reset the query count to 0
+  void Reset();
+
+  // Increment the query count by 1
+  void Incr();
+
+  // Return the current qps (i.e query count divided by the time since this
+  // QpsGauge object created (or Reset() was called))
   long Get();
 
  private:
-  long val_;
-  std::mutex val_mu_;
+  gpr_timespec start_time_;
+  long num_queries_;
+  std::mutex num_queries_mu_;
 };
 
 class MetricsServiceImpl GRPC_FINAL : public MetricsService::Service {
@@ -81,17 +92,17 @@ class MetricsServiceImpl GRPC_FINAL : public MetricsService::Service {
   grpc::Status GetGauge(ServerContext* context, const GaugeRequest* request,
                         GaugeResponse* response) GRPC_OVERRIDE;
 
-  // Create a Gauge with name 'name'. is_present is set to true if the Gauge
+  // Create a QpsGauge with name 'name'. is_present is set to true if the Gauge
   // is already present in the map.
-  // NOTE: CreateGauge can be called anytime (i.e before or after calling
+  // NOTE: CreateQpsGauge can be called anytime (i.e before or after calling
   // StartServer).
-  std::shared_ptr<Gauge> CreateGauge(const grpc::string& name,
+  std::shared_ptr<QpsGauge> CreateQpsGauge(const grpc::string& name,
                                      bool* already_present);
 
   std::unique_ptr<grpc::Server> StartServer(int port);
 
  private:
-  std::map<string, std::shared_ptr<Gauge>> gauges_;
+  std::map<string, std::shared_ptr<QpsGauge>> qps_gauges_;
   std::mutex mu_;
 };
 

tools/run_tests/stress_test/STRESS_CLIENT_SPEC.md

@@ -6,8 +6,8 @@ This document specifies the features a stress test client should implement in or
 --------------
 **1.** A stress test client should be able to repeatedly execute one or more of the existing 'interop test cases'. It may just be a wrapper around the existing interop test client. The exact command line arguments the client should support are listed in _Table 1_ below.
 
-**2.** The stress test client must implement a metrics server defined by _[metrics.proto](https://github.com/grpc/grpc/blob/master/src/proto/grpc/testing/metrics.proto)_ and must expose _qps_ as a long-valued Gauge. The client can track the overall _qps_ in one Gauge or in multiple Gauges (for example: One per Channel or Stub).
- The framework periodically queries the _qps_ by calling the `GetAllGauges()` method (the framework assumes that all the returned Gauges are _qps_ Gauges) and uses this to determine if the stress test client is running or crashed or stalled.
+**2.** The stress test client must implement a metrics server defined by _[metrics.proto](https://github.com/grpc/grpc/blob/master/src/proto/grpc/testing/metrics.proto)_ and must expose _qps_ as a `Long`-valued Gauge. The client can track the overall _qps_ in one Gauge or in multiple Gauges (for example: One per Channel or Stub).
+ The framework periodically queries the _qps_ by calling the `GetAllGauges()` method (the framework assumes that all the returned Gauges are _qps_ Gauges and adds them up to determine the final qps) and uses this to determine if the stress test client is running or crashed or stalled.
 > *Note:* In this context, the term  _**qps**_  means _interop test cases per second_  (not _messages per second_ or _rpc calls per second_)
 
 

tools/run_tests/stress_test/configs/asan.json

@@ -16,8 +16,7 @@
           "num_channels_per_server":5,
           "num_stubs_per_channel":10,
           "test_cases": "empty_unary:1,large_unary:1,client_streaming:1,server_streaming:1,empty_stream:1",
-          "metrics_port": 8081,
-          "metrics_collection_interval_secs":120
+          "metrics_port": 8081
         },
         "metricsPort": 8081,
         "metricsArgs": {

tools/run_tests/stress_test/configs/opt-tsan-asan.json

@@ -26,8 +26,7 @@
           "num_channels_per_server":5,
           "num_stubs_per_channel":10,
           "test_cases": "empty_unary:1,large_unary:1,client_streaming:1,server_streaming:1,empty_stream:1",
-          "metrics_port": 8081,
-          "metrics_collection_interval_secs": 60
+          "metrics_port": 8081
         },
         "metricsPort": 8081,
         "metricsArgs": {

tools/run_tests/stress_test/configs/opt.json

@@ -16,8 +16,7 @@
           "num_channels_per_server":5,
           "num_stubs_per_channel":10,
           "test_cases": "empty_unary:1,large_unary:1,client_streaming:1,server_streaming:1,empty_stream:1",
-          "metrics_port": 8081,
-          "metrics_collection_interval_secs": 60
+          "metrics_port": 8081
         },
         "metricsPort": 8081,
         "metricsArgs": {

tools/run_tests/stress_test/configs/tsan.json

@@ -16,8 +16,7 @@
           "num_channels_per_server":5,
           "num_stubs_per_channel":10,
           "test_cases": "empty_unary:1,large_unary:1,client_streaming:1,server_streaming:1,empty_stream:1",
-          "metrics_port": 8081,
-          "metrics_collection_interval_secs":120
+          "metrics_port": 8081
         },
         "metricsPort": 8081,
         "metricsArgs": {