Change flag precision to flag stride, better description.

Add flag error_tolerence to define the search stopping criteria.
Move the equal condition in the binary search to smaller than condition.
Wrap get_cpu_usage(), so on non-linux platform, the compiler won't
complain and will get cpu usage to be 0.

1 files changed, 138 insertions, 133 deletions

diff --git a/test/cpp/qps/qps_json_driver.cc b/test/cpp/qps/qps_json_driver.cc
index e16fb165f0..d3526da2b7 100644
--- a/test/cpp/qps/qps_json_driver.cc
+++ b/test/cpp/qps/qps_json_driver.cc
@@ -51,164 +51,169 @@ DEFINE_string(scenarios_json, "",
 DEFINE_bool(quit, false, "Quit the workers");
 DEFINE_string(search_param, "",
               "The parameter, whose value is to be searched for to achieve "
-              "targeted cpu load");
+              "targeted cpu load. For now, we have 'offered_load'. Later, "
+              "'num_channels', 'num_outstanding_requests', etc. shall be "
+              "added.");
 DEFINE_double(
     initial_search_value, 0.0,
     "initial parameter value to start the search with (i.e. lower bound)");
 DEFINE_double(targeted_cpu_load, 70.0,
               "Targeted cpu load (unit: %, range [0,100])");
-DEFINE_double(precision, 1,
-              "Threshold for the search range, below which will end the "
-              "search. Also defines each stride of the search.");
-
-namespace grpc {
-namespace testing {
-
-static std::unique_ptr<ScenarioResult> RunAndReport(const Scenario& scenario,
-                                                    bool* success) {
-  std::cerr << "RUNNING SCENARIO: " << scenario.name() << "\n";
-  auto result =
-      RunScenario(scenario.client_config(), scenario.num_clients(),
-                  scenario.server_config(), scenario.num_servers(),
-                  scenario.warmup_seconds(), scenario.benchmark_seconds(),
-                  scenario.spawn_local_worker_count());
-
-  // Amend the result with scenario config. Eventually we should adjust
-  // RunScenario contract so we don't need to touch the result here.
-  result->mutable_scenario()->CopyFrom(scenario);
-
-  GetReporter()->ReportQPS(*result);
-  GetReporter()->ReportQPSPerCore(*result);
-  GetReporter()->ReportLatency(*result);
-  GetReporter()->ReportTimes(*result);
-  GetReporter()->ReportCpuUsage(*result);
-
-  for (int i = 0; *success && i < result->client_success_size(); i++) {
-    *success = result->client_success(i);
+DEFINE_double(stride, 1,
+              "Defines each stride of the search. The larger the stride is, "
+              "the coarser the result will be, but will also be faster.");
+DEFINE_double(error_tolerance, 0.01,
+              "Defines threshold for stopping the search. When current search "
+              "range is narrower than the error_tolerance computed range, we "
+              "stop the search.");
+
+    namespace grpc {
+  namespace testing {
+
+  static std::unique_ptr<ScenarioResult> RunAndReport(const Scenario& scenario,
+                                                      bool* success) {
+    std::cerr << "RUNNING SCENARIO: " << scenario.name() << "\n";
+    auto result =
+        RunScenario(scenario.client_config(), scenario.num_clients(),
+                    scenario.server_config(), scenario.num_servers(),
+                    scenario.warmup_seconds(), scenario.benchmark_seconds(),
+                    scenario.spawn_local_worker_count());
+
+    // Amend the result with scenario config. Eventually we should adjust
+    // RunScenario contract so we don't need to touch the result here.
+    result->mutable_scenario()->CopyFrom(scenario);
+
+    GetReporter()->ReportQPS(*result);
+    GetReporter()->ReportQPSPerCore(*result);
+    GetReporter()->ReportLatency(*result);
+    GetReporter()->ReportTimes(*result);
+    GetReporter()->ReportCpuUsage(*result);
+
+    for (int i = 0; *success && i < result->client_success_size(); i++) {
+      *success = result->client_success(i);
+    }
+    for (int i = 0; *success && i < result->server_success_size(); i++) {
+      *success = result->server_success(i);
+    }
+
+    return result;
   }
-  for (int i = 0; *success && i < result->server_success_size(); i++) {
-    *success = result->server_success(i);
+
+  static double GetCpuLoad(Scenario* scenario, double offered_load,
+                           bool* success) {
+    scenario->mutable_client_config()
+        ->mutable_load_params()
+        ->mutable_poisson()
+        ->set_offered_load(offered_load);
+    auto result = RunAndReport(*scenario, success);
+    return result->summary().server_cpu_usage();
   }
 
-  return result;
-}
+  static double BinarySearch(Scenario* scenario, double targeted_cpu_load,
+                             double low, double high, bool* success) {
+    while (low <= high * (1 - FLAGS_error_tolerance)) {
+      double mid = low + (high - low) / 2;
+      double current_cpu_load = GetCpuLoad(scenario, mid, success);
+      gpr_log(GPR_DEBUG, "Binary Search: current_offered_load %.0f", mid);
+      if (!*success) {
+        gpr_log(GPR_ERROR, "Client/Server Failure");
+        break;
+      }
+      if (targeted_cpu_load <= current_cpu_load) {
+        high = mid - FLAGS_stride;
+      } else {
+        low = mid + FLAGS_stride;
+      }
+    }
 
-static double GetCpuLoad(Scenario* scenario, double offered_load,
-                         bool* success) {
-  scenario->mutable_client_config()
-      ->mutable_load_params()
-      ->mutable_poisson()
-      ->set_offered_load(offered_load);
-  auto result = RunAndReport(*scenario, success);
-  return result->summary().server_cpu_usage();
-}
+    return low;
+  }
 
-static double BinarySearch(Scenario* scenario, double targeted_cpu_load,
-                           double low, double high, bool* success) {
-  while (low <= high - FLAGS_precision) {
-    double mid = low + (high - low) / 2;
-    double current_cpu_load = GetCpuLoad(scenario, mid, success);
-    gpr_log(GPR_DEBUG, "Binary Search: current_offered_load %.0f", mid);
-    if (!*success) {
-      gpr_log(GPR_ERROR, "Client/Server Failure");
-      break;
+  static double SearchOfferedLoad(double initial_offered_load,
+                                  double targeted_cpu_load, Scenario* scenario,
+                                  bool* success) {
+    std::cerr << "RUNNING SCENARIO: " << scenario->name() << "\n";
+    double current_offered_load = initial_offered_load;
+    double current_cpu_load =
+        GetCpuLoad(scenario, current_offered_load, success);
+    if (current_cpu_load > targeted_cpu_load) {
+      gpr_log(GPR_ERROR, "Initial offered load too high");
+      return -1;
     }
-    if (targeted_cpu_load < current_cpu_load) {
-      high = mid - FLAGS_precision;
-    } else if (targeted_cpu_load > current_cpu_load) {
-      low = mid + FLAGS_precision;
-    } else {
-      high = mid - FLAGS_precision;
-    }
-  }
 
-  return low;
-}
+    while (*success && (current_cpu_load < targeted_cpu_load)) {
+      current_offered_load *= 2;
+      current_cpu_load = GetCpuLoad(scenario, current_offered_load, success);
+      gpr_log(GPR_DEBUG, "Binary Search: current_offered_load  %.0f",
+              current_offered_load);
+    }
 
-static double SearchOfferedLoad(double initial_offered_load,
-                                double targeted_cpu_load, Scenario* scenario,
-                                bool* success) {
-  std::cerr << "RUNNING SCENARIO: " << scenario->name() << "\n";
-  double current_offered_load = initial_offered_load;
-  double current_cpu_load = GetCpuLoad(scenario, current_offered_load, success);
-  if (current_cpu_load > targeted_cpu_load) {
-    gpr_log(GPR_ERROR, "Initial offered load too high");
-    return -1;
-  }
+    double targeted_offered_load =
+        BinarySearch(scenario, targeted_cpu_load, current_offered_load / 2,
+                     current_offered_load, success);
 
-  while (*success && (current_cpu_load < targeted_cpu_load)) {
-    current_offered_load *= 2;
-    current_cpu_load = GetCpuLoad(scenario, current_offered_load, success);
-    gpr_log(GPR_DEBUG, "Binary Search: current_offered_load  %.0f",
-            current_offered_load);
+    return targeted_offered_load;
   }
 
-  double targeted_offered_load =
-      BinarySearch(scenario, targeted_cpu_load, current_offered_load / 2,
-                   current_offered_load, success);
+  static bool QpsDriver() {
+    grpc::string json;
+
+    bool scfile = (FLAGS_scenarios_file != "");
+    bool scjson = (FLAGS_scenarios_json != "");
+    if ((!scfile && !scjson && !FLAGS_quit) ||
+        (scfile && (scjson || FLAGS_quit)) || (scjson && FLAGS_quit)) {
+      gpr_log(GPR_ERROR,
+              "Exactly one of --scenarios_file, --scenarios_json, "
+              "or --quit must be set");
+      abort();
+    }
 
-  return targeted_offered_load;
-}
+    if (scfile) {
+      // Read the json data from disk
+      FILE* json_file = fopen(FLAGS_scenarios_file.c_str(), "r");
+      GPR_ASSERT(json_file != NULL);
+      fseek(json_file, 0, SEEK_END);
+      long len = ftell(json_file);
+      char* data = new char[len];
+      fseek(json_file, 0, SEEK_SET);
+      GPR_ASSERT(len == (long)fread(data, 1, len, json_file));
+      fclose(json_file);
+      json = grpc::string(data, data + len);
+      delete[] data;
+    } else if (scjson) {
+      json = FLAGS_scenarios_json.c_str();
+    } else if (FLAGS_quit) {
+      return RunQuit();
+    }
 
-static bool QpsDriver() {
-  grpc::string json;
-
-  bool scfile = (FLAGS_scenarios_file != "");
-  bool scjson = (FLAGS_scenarios_json != "");
-  if ((!scfile && !scjson && !FLAGS_quit) ||
-      (scfile && (scjson || FLAGS_quit)) || (scjson && FLAGS_quit)) {
-    gpr_log(GPR_ERROR,
-            "Exactly one of --scenarios_file, --scenarios_json, "
-            "or --quit must be set");
-    abort();
-  }
+    // Parse into an array of scenarios
+    Scenarios scenarios;
+    ParseJson(json.c_str(), "grpc.testing.Scenarios", &scenarios);
+    bool success = true;
 
-  if (scfile) {
-    // Read the json data from disk
-    FILE* json_file = fopen(FLAGS_scenarios_file.c_str(), "r");
-    GPR_ASSERT(json_file != NULL);
-    fseek(json_file, 0, SEEK_END);
-    long len = ftell(json_file);
-    char* data = new char[len];
-    fseek(json_file, 0, SEEK_SET);
-    GPR_ASSERT(len == (long)fread(data, 1, len, json_file));
-    fclose(json_file);
-    json = grpc::string(data, data + len);
-    delete[] data;
-  } else if (scjson) {
-    json = FLAGS_scenarios_json.c_str();
-  } else if (FLAGS_quit) {
-    return RunQuit();
-  }
+    // Make sure that there is at least some valid scenario here
+    GPR_ASSERT(scenarios.scenarios_size() > 0);
 
-  // Parse into an array of scenarios
-  Scenarios scenarios;
-  ParseJson(json.c_str(), "grpc.testing.Scenarios", &scenarios);
-  bool success = true;
-
-  // Make sure that there is at least some valid scenario here
-  GPR_ASSERT(scenarios.scenarios_size() > 0);
-
-  for (int i = 0; i < scenarios.scenarios_size(); i++) {
-    if (FLAGS_search_param == "") {
-      const Scenario& scenario = scenarios.scenarios(i);
-      RunAndReport(scenario, &success);
-    } else {
-      if (FLAGS_search_param == "offered_load") {
-        Scenario* scenario = scenarios.mutable_scenarios(i);
-        double targeted_offered_load =
-            SearchOfferedLoad(FLAGS_initial_search_value,
-                              FLAGS_targeted_cpu_load, scenario, &success);
-        gpr_log(GPR_INFO, "targeted_offered_load %f", targeted_offered_load);
+    for (int i = 0; i < scenarios.scenarios_size(); i++) {
+      if (FLAGS_search_param == "") {
+        const Scenario& scenario = scenarios.scenarios(i);
+        RunAndReport(scenario, &success);
       } else {
-        gpr_log(GPR_ERROR, "Unimplemented search param");
+        if (FLAGS_search_param == "offered_load") {
+          Scenario* scenario = scenarios.mutable_scenarios(i);
+          double targeted_offered_load =
+              SearchOfferedLoad(FLAGS_initial_search_value,
+                                FLAGS_targeted_cpu_load, scenario, &success);
+          gpr_log(GPR_INFO, "targeted_offered_load %f", targeted_offered_load);
+        } else {
+          gpr_log(GPR_ERROR, "Unimplemented search param");
+        }
       }
     }
+    return success;
   }
-  return success;
-}
 
-}  // namespace testing
+  }  // namespace testing
 }  // namespace grpc
 
 int main(int argc, char** argv) {