private void initMetrics()

in grpc-gcp/src/main/java/com/google/cloud/grpc/GcpManagedChannel.java [319:530]
184 lines of code
3 McCabe index (conditional complexity)

  private void initMetrics() {
    final GcpMetricsOptions metricsOptions = options.getMetricsOptions();
    if (metricsOptions == null) {
      logger.info(log("Metrics options are empty. Metrics disabled."));
      initLogMetrics();
      return;
    }
    logMetricsOptions();
    if (metricsOptions.getMetricRegistry() == null) {
      logger.info(log("Metric registry is null. Metrics disabled."));
      initLogMetrics();
      return;
    }
    logger.info(log("Metrics enabled."));

    metricRegistry = metricsOptions.getMetricRegistry();
    labelKeys.addAll(metricsOptions.getLabelKeys());
    labelKeysWithResult.addAll(metricsOptions.getLabelKeys());
    labelValues.addAll(metricsOptions.getLabelValues());
    labelValuesSuccess.addAll(metricsOptions.getLabelValues());
    labelValuesError.addAll(metricsOptions.getLabelValues());

    final LabelKey poolKey =
        LabelKey.create(GcpMetricsConstants.POOL_INDEX_LABEL, GcpMetricsConstants.POOL_INDEX_DESC);
    labelKeys.add(poolKey);
    labelKeysWithResult.add(poolKey);
    final LabelValue poolIndex = LabelValue.create(metricPoolIndex);
    labelValues.add(poolIndex);
    labelValuesSuccess.add(poolIndex);
    labelValuesError.add(poolIndex);

    metricPrefix = metricsOptions.getNamePrefix();

    createDerivedLongGaugeTimeSeries(
        GcpMetricsConstants.METRIC_MIN_READY_CHANNELS,
        "The minimum number of channels simultaneously in the READY state.",
        GcpMetricsConstants.COUNT,
        this,
        GcpManagedChannel::reportMinReadyChannels);

    createDerivedLongGaugeTimeSeries(
        GcpMetricsConstants.METRIC_MAX_READY_CHANNELS,
        "The maximum number of channels simultaneously in the READY state.",
        GcpMetricsConstants.COUNT,
        this,
        GcpManagedChannel::reportMaxReadyChannels);

    createDerivedLongGaugeTimeSeries(
        GcpMetricsConstants.METRIC_MAX_CHANNELS,
        "The maximum number of channels in the pool.",
        GcpMetricsConstants.COUNT,
        this,
        GcpManagedChannel::reportMaxChannels);

    createDerivedLongGaugeTimeSeries(
        GcpMetricsConstants.METRIC_MAX_ALLOWED_CHANNELS,
        "The maximum number of channels allowed in the pool. (The poll max size)",
        GcpMetricsConstants.COUNT,
        this,
        GcpManagedChannel::reportMaxAllowedChannels);

    createDerivedLongCumulativeTimeSeries(
        GcpMetricsConstants.METRIC_NUM_CHANNEL_DISCONNECT,
        "The number of disconnections (occurrences when a channel deviates from the READY state)",
        GcpMetricsConstants.COUNT,
        this,
        GcpManagedChannel::reportNumChannelDisconnect);

    createDerivedLongCumulativeTimeSeries(
        GcpMetricsConstants.METRIC_NUM_CHANNEL_CONNECT,
        "The number of times when a channel reached the READY state.",
        GcpMetricsConstants.COUNT,
        this,
        GcpManagedChannel::reportNumChannelConnect);

    createDerivedLongGaugeTimeSeries(
        GcpMetricsConstants.METRIC_MIN_CHANNEL_READINESS_TIME,
        "The minimum time it took to transition a channel to the READY state.",
        GcpMetricsConstants.MICROSECOND,
        this,
        GcpManagedChannel::reportMinReadinessTime);

    createDerivedLongGaugeTimeSeries(
        GcpMetricsConstants.METRIC_AVG_CHANNEL_READINESS_TIME,
        "The average time it took to transition a channel to the READY state.",
        GcpMetricsConstants.MICROSECOND,
        this,
        GcpManagedChannel::reportAvgReadinessTime);

    createDerivedLongGaugeTimeSeries(
        GcpMetricsConstants.METRIC_MAX_CHANNEL_READINESS_TIME,
        "The maximum time it took to transition a channel to the READY state.",
        GcpMetricsConstants.MICROSECOND,
        this,
        GcpManagedChannel::reportMaxReadinessTime);

    createDerivedLongGaugeTimeSeries(
        GcpMetricsConstants.METRIC_MIN_ACTIVE_STREAMS,
        "The minimum number of active streams on any channel.",
        GcpMetricsConstants.COUNT,
        this,
        GcpManagedChannel::reportMinActiveStreams);

    createDerivedLongGaugeTimeSeries(
        GcpMetricsConstants.METRIC_MAX_ACTIVE_STREAMS,
        "The maximum number of active streams on any channel.",
        GcpMetricsConstants.COUNT,
        this,
        GcpManagedChannel::reportMaxActiveStreams);

    createDerivedLongGaugeTimeSeries(
        GcpMetricsConstants.METRIC_MIN_TOTAL_ACTIVE_STREAMS,
        "The minimum total number of active streams across all channels.",
        GcpMetricsConstants.COUNT,
        this,
        GcpManagedChannel::reportMinTotalActiveStreams);

    createDerivedLongGaugeTimeSeries(
        GcpMetricsConstants.METRIC_MAX_TOTAL_ACTIVE_STREAMS,
        "The maximum total number of active streams across all channels.",
        GcpMetricsConstants.COUNT,
        this,
        GcpManagedChannel::reportMaxTotalActiveStreams);

    createDerivedLongGaugeTimeSeries(
        GcpMetricsConstants.METRIC_MIN_AFFINITY,
        "The minimum number of affinity count on any channel.",
        GcpMetricsConstants.COUNT,
        this,
        GcpManagedChannel::reportMinAffinity);

    createDerivedLongGaugeTimeSeries(
        GcpMetricsConstants.METRIC_MAX_AFFINITY,
        "The maximum number of affinity count on any channel.",
        GcpMetricsConstants.COUNT,
        this,
        GcpManagedChannel::reportMaxAffinity);

    createDerivedLongGaugeTimeSeries(
        GcpMetricsConstants.METRIC_NUM_AFFINITY,
        "The total number of affinity count across all channels.",
        GcpMetricsConstants.COUNT,
        this,
        GcpManagedChannel::reportNumAffinity);

    createDerivedLongGaugeTimeSeriesWithResult(
        GcpMetricsConstants.METRIC_MIN_CALLS,
        "The minimum number of completed calls on any channel.",
        GcpMetricsConstants.COUNT,
        this,
        GcpManagedChannel::reportMinOkCalls,
        GcpManagedChannel::reportMinErrCalls);

    createDerivedLongGaugeTimeSeriesWithResult(
        GcpMetricsConstants.METRIC_MAX_CALLS,
        "The maximum number of completed calls on any channel.",
        GcpMetricsConstants.COUNT,
        this,
        GcpManagedChannel::reportMaxOkCalls,
        GcpManagedChannel::reportMaxErrCalls);

    createDerivedLongCumulativeTimeSeriesWithResult(
        GcpMetricsConstants.METRIC_NUM_CALLS_COMPLETED,
        "The number of calls completed across all channels.",
        GcpMetricsConstants.COUNT,
        this,
        GcpManagedChannel::reportTotalOkCalls,
        GcpManagedChannel::reportTotalErrCalls);

    createDerivedLongCumulativeTimeSeriesWithResult(
        GcpMetricsConstants.METRIC_NUM_FALLBACKS,
        "The number of calls that had fallback to another channel.",
        GcpMetricsConstants.COUNT,
        this,
        GcpManagedChannel::reportSucceededFallbacks,
        GcpManagedChannel::reportFailedFallbacks);

    createDerivedLongCumulativeTimeSeries(
        GcpMetricsConstants.METRIC_NUM_UNRESPONSIVE_DETECTIONS,
        "The number of unresponsive connections detected.",
        GcpMetricsConstants.COUNT,
        this,
        GcpManagedChannel::reportUnresponsiveDetectionCount);

    createDerivedLongGaugeTimeSeries(
        GcpMetricsConstants.METRIC_MIN_UNRESPONSIVE_DETECTION_TIME,
        "The minimum time it took to detect an unresponsive connection.",
        GcpMetricsConstants.MILLISECOND,
        this,
        GcpManagedChannel::reportMinUnresponsiveMs);

    createDerivedLongGaugeTimeSeries(
        GcpMetricsConstants.METRIC_MAX_UNRESPONSIVE_DETECTION_TIME,
        "The maximum time it took to detect an unresponsive connection.",
        GcpMetricsConstants.MILLISECOND,
        this,
        GcpManagedChannel::reportMaxUnresponsiveMs);

    createDerivedLongGaugeTimeSeries(
        GcpMetricsConstants.METRIC_MIN_UNRESPONSIVE_DROPPED_CALLS,
        "The minimum calls dropped before detection of an unresponsive connection.",
        GcpMetricsConstants.MILLISECOND,
        this,
        GcpManagedChannel::reportMinUnresponsiveDrops);

    createDerivedLongGaugeTimeSeries(
        GcpMetricsConstants.METRIC_MAX_UNRESPONSIVE_DROPPED_CALLS,
        "The maximum calls dropped before detection of an unresponsive connection.",
        GcpMetricsConstants.MILLISECOND,
        this,
        GcpManagedChannel::reportMaxUnresponsiveDrops);
  }