xref: /aosp_15_r20/external/grpc-grpc/examples/cpp/otel/ostream/greeter_callback_server.cc (revision cc02d7e222339f7a4f6ba5f422e6413f4bd931f2)
1 /*
2  *
3  * Copyright 2021 gRPC authors.
4  *
5  * Licensed under the Apache License, Version 2.0 (the "License");
6  * you may not use this file except in compliance with the License.
7  * You may obtain a copy of the License at
8  *
9  *     http://www.apache.org/licenses/LICENSE-2.0
10  *
11  * Unless required by applicable law or agreed to in writing, software
12  * distributed under the License is distributed on an "AS IS" BASIS,
13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14  * See the License for the specific language governing permissions and
15  * limitations under the License.
16  *
17  */
18 
19 // Explicitly define HAVE_ABSEIL to avoid conflict with OTel's Abseil
20 // version. Refer
21 // https://github.com/open-telemetry/opentelemetry-cpp/issues/1042.
22 #ifndef HAVE_ABSEIL
23 #define HAVE_ABSEIL
24 #endif
25 
26 #include <iostream>
27 #include <memory>
28 #include <string>
29 
30 #include "absl/flags/flag.h"
31 #include "absl/flags/parse.h"
32 #include "opentelemetry/exporters/ostream/metric_exporter.h"
33 #include "opentelemetry/exporters/ostream/metric_exporter_factory.h"
34 #include "opentelemetry/sdk/metrics/export/periodic_exporting_metric_reader.h"
35 #include "opentelemetry/sdk/metrics/export/periodic_exporting_metric_reader_factory.h"
36 #include "opentelemetry/sdk/metrics/meter_provider.h"
37 
38 #include <grpcpp/ext/otel_plugin.h>
39 
40 #ifdef BAZEL_BUILD
41 #include "examples/cpp/otel/util.h"
42 #else
43 #include "../util.h"
44 #endif
45 
46 ABSL_FLAG(uint16_t, port, 50051, "Server port for the service");
47 
main(int argc,char ** argv)48 int main(int argc, char** argv) {
49   absl::ParseCommandLine(argc, argv);
50   // Register a global gRPC OpenTelemetry plugin configured with an ostream
51   // exporter.
52   auto ostream_exporter =
53       opentelemetry::exporter::metrics::OStreamMetricExporterFactory::Create();
54   opentelemetry::sdk::metrics::PeriodicExportingMetricReaderOptions
55       reader_options;
56   reader_options.export_interval_millis = std::chrono::milliseconds(1000);
57   reader_options.export_timeout_millis = std::chrono::milliseconds(500);
58   auto reader =
59       opentelemetry::sdk::metrics::PeriodicExportingMetricReaderFactory::Create(
60           std::move(ostream_exporter), reader_options);
61   auto meter_provider =
62       std::make_shared<opentelemetry::sdk::metrics::MeterProvider>();
63   // The default histogram boundaries are not granular enough for RPCs. Override
64   // the "grpc.server.call.duration" view as recommended by
65   // https://github.com/grpc/proposal/blob/master/A66-otel-stats.md.
66   AddLatencyView(meter_provider.get(), "grpc.server.call.duration", "s");
67   meter_provider->AddMetricReader(std::move(reader));
68   auto status = grpc::OpenTelemetryPluginBuilder()
69                     .SetMeterProvider(std::move(meter_provider))
70                     .BuildAndRegisterGlobal();
71   if (!status.ok()) {
72     std::cerr << "Failed to register gRPC OpenTelemetry Plugin: "
73               << status.ToString() << std::endl;
74     return static_cast<int>(status.code());
75   }
76   RunServer(absl::GetFlag(FLAGS_port));
77   return 0;
78 }
79