Collect stats on # failed requests

src/proto/grpc/testing/control.proto

@@ -219,6 +219,7 @@ message ScenarioResultSummary
   double latency_99 = 10;
   double latency_999 = 11;
 
+  // Number of requests that succeeded/failed
   int64 successful_requests = 12;
   int64 failed_requests = 13;
 }

test/cpp/qps/driver.cc

@@ -169,6 +169,8 @@ static void postprocess_scenario_result(ScenarioResult* result) {
         failures += rrc.count();
       }
     }
+    result->mutable_summary()->set_successful_requests(successes);
+    result->mutable_summary()->set_failed_requests(successes);
   }
 }
 

test/cpp/qps/qps_json_driver.cc

@@ -110,6 +110,11 @@ static bool QpsDriver() {
     GetReporter()->ReportLatency(*result);
     GetReporter()->ReportTimes(*result);
 
+    if (result->mutable_summary()->failed_requests()) {
+      std::cerr << "# failed requests: "
+                << result->mutable_summary()->failed_requests() << "\n";
+    }
+
     for (int i = 0; success && i < result->client_success_size(); i++) {
       success = result->client_success(i);
     }