Class OrcaServiceImpl

xds/src/main/java/io/grpc/xds/orca/OrcaServiceImpl.java:45–161

Implements a BindableService that generates Out-Of-Band server metrics. Register the returned service to the server, then a client can request for periodic load reports.

 * Register the returned service to the server, then a client can request for periodic load reports.
 */
@ExperimentalApi("https://github.com/grpc/grpc-java/issues/9006")
public final class OrcaServiceImpl implements BindableService {
  private static final Logger logger = Logger.getLogger(OrcaServiceImpl.class.getName());

  /**
   * Empty or invalid (non-positive) minInterval config in will be treated to this default value.
   */
  public static final long DEFAULT_MIN_REPORT_INTERVAL_NANOS = TimeUnit.SECONDS.toNanos(30);

  private final long minReportIntervalNanos;
  private final ScheduledExecutorService timeService;
  @VisibleForTesting
  final AtomicInteger clientCount = new AtomicInteger(0);
  private MetricRecorder metricRecorder;
  private final RealOrcaServiceImpl delegate = new RealOrcaServiceImpl();

  /**
   * Constructs a service to report server metrics. Config the report interval lower bound, the
   * executor to run the timer, and a {@link MetricRecorder} that contains metrics data.
   *
   * @param minInterval configures the minimum metrics reporting interval for the
   *        service. Bad configuration (non-positive) will be overridden to service default (30s).
   *        Minimum metrics reporting interval means, if the setting in the client's
   *        request is invalid (non-positive) or below this value, they will be treated
   *        as this value.
   */
  public static BindableService createService(ScheduledExecutorService timeService,
                                              MetricRecorder metricsRecorder,
                                              long minInterval, TimeUnit timeUnit) {
    return new OrcaServiceImpl(minInterval, timeUnit, timeService,  metricsRecorder);
  }

  public static BindableService createService(ScheduledExecutorService timeService,
                                       MetricRecorder metricRecorder) {
    return new OrcaServiceImpl(DEFAULT_MIN_REPORT_INTERVAL_NANOS, TimeUnit.NANOSECONDS,
        timeService, metricRecorder);
  }

  private OrcaServiceImpl(long minInterval, TimeUnit timeUnit, ScheduledExecutorService timeService,
                         MetricRecorder orcaMetrics) {
    this.minReportIntervalNanos = minInterval > 0 ? timeUnit.toNanos(minInterval)
        : DEFAULT_MIN_REPORT_INTERVAL_NANOS;
    this.timeService = checkNotNull(timeService, "timeService");
    this.metricRecorder = checkNotNull(orcaMetrics, "orcaMetrics");
  }

  @Override
  public ServerServiceDefinition bindService() {
    return delegate.bindService();
  }

  private final class RealOrcaServiceImpl extends OpenRcaServiceGrpc.OpenRcaServiceImplBase {
    @Override
    public void streamCoreMetrics(
        OrcaLoadReportRequest request, StreamObserver<OrcaLoadReport> responseObserver) {
      OrcaClient client = new OrcaClient(request, responseObserver);
      client.run();
      clientCount.getAndIncrement();