mlbiscoc commented on code in PR #2405: URL: https://github.com/apache/solr/pull/2405#discussion_r1610675745
########## solr/core/src/java/org/apache/solr/metrics/prometheus/SolrPrometheusExporter.java: ########## @@ -0,0 +1,203 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You under the Apache License, Version 2.0 + * (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +package org.apache.solr.metrics.prometheus; + +import com.codahale.metrics.Meter; +import com.codahale.metrics.Metric; +import com.codahale.metrics.Timer; +import io.prometheus.metrics.model.snapshots.CounterSnapshot; +import io.prometheus.metrics.model.snapshots.GaugeSnapshot; +import io.prometheus.metrics.model.snapshots.Labels; +import io.prometheus.metrics.model.snapshots.MetricMetadata; +import io.prometheus.metrics.model.snapshots.MetricSnapshot; +import io.prometheus.metrics.model.snapshots.MetricSnapshots; +import java.util.ArrayList; +import java.util.HashMap; +import java.util.List; +import java.util.Map; + +/** + * Base class for all {@link SolrPrometheusExporter} holding {@link MetricSnapshot}s. Can export + * {@link com.codahale.metrics.Metric} to {@link MetricSnapshot} to be outputted for {@link + * org.apache.solr.response.PrometheusResponseWriter} + */ +public abstract class SolrPrometheusExporter implements PrometheusExporterInfo { + protected final Map<String, List<CounterSnapshot.CounterDataPointSnapshot>> metricCounters; + protected final Map<String, List<GaugeSnapshot.GaugeDataPointSnapshot>> metricGauges; + + public SolrPrometheusExporter() { + this.metricCounters = new HashMap<>(); + this.metricGauges = new HashMap<>(); + } + + /** + * Export {@link Metric} to {@link io.prometheus.metrics.model.snapshots.MetricSnapshot} and + * registers the Snapshot + * + * @param dropwizardMetric the {@link Metric} to be exported + * @param metricName Dropwizard metric name + */ + public abstract void exportDropwizardMetric(Metric dropwizardMetric, String metricName); + + /** + * Export {@link Meter} to {@link + * io.prometheus.metrics.model.snapshots.CounterSnapshot.CounterDataPointSnapshot} and collect + * datapoint + * + * @param metricName name of metric after export + * @param dropwizardMetric the {@link Meter} to be exported + * @param labels label names and values to record + */ + public void exportMeter(String metricName, Meter dropwizardMetric, Labels labels) { + CounterSnapshot.CounterDataPointSnapshot dataPoint = + createCounterDatapoint((double) dropwizardMetric.getCount(), labels); + collectCounterDatapoint(metricName, dataPoint); + } + + /** + * Export {@link com.codahale.metrics.Counter} to {@link + * io.prometheus.metrics.model.snapshots.CounterSnapshot.CounterDataPointSnapshot} and collect + * datapoint + * + * @param metricName name of prometheus metric + * @param dropwizardMetric the {@link com.codahale.metrics.Counter} to be exported + * @param labels label names and values to record + */ + public void exportCounter( + String metricName, com.codahale.metrics.Counter dropwizardMetric, Labels labels) { + CounterSnapshot.CounterDataPointSnapshot dataPoint = + createCounterDatapoint((double) dropwizardMetric.getCount(), labels); + collectCounterDatapoint(metricName, dataPoint); + } + + /** + * Export {@link Timer} ands its mean rate to {@link + * io.prometheus.metrics.model.snapshots.GaugeSnapshot.GaugeDataPointSnapshot} and collect + * datapoint + * + * @param metricName name of prometheus metric + * @param dropwizardMetric the {@link Timer} to be exported + * @param labels label names and values to record + */ + public void exportTimer(String metricName, Timer dropwizardMetric, Labels labels) { + GaugeSnapshot.GaugeDataPointSnapshot dataPoint = + createGaugeDatapoint(dropwizardMetric.getSnapshot().getMean(), labels); + collectGaugeDatapoint(metricName, dataPoint); + } + + /** + * Export {@link com.codahale.metrics.Gauge} to {@link + * io.prometheus.metrics.model.snapshots.GaugeSnapshot.GaugeDataPointSnapshot} and collect to + * datapoint. Unlike other Dropwizard metric types, Gauges can have more complex types. In the + * case of a hashmap, collect each as an individual metric and have its key appended as a label to + * the metric called "item" + * + * @param metricName name of prometheus metric + * @param dropwizardMetricRaw the {@link com.codahale.metrics.Gauge} to be exported + * @param labels label names and values to record + */ + public void exportGauge( + String metricName, com.codahale.metrics.Gauge<?> dropwizardMetricRaw, Labels labels) { + Object dropwizardMetric = (dropwizardMetricRaw).getValue(); + if (dropwizardMetric instanceof Number) { + GaugeSnapshot.GaugeDataPointSnapshot dataPoint = + createGaugeDatapoint(((Number) dropwizardMetric).doubleValue(), labels); + collectGaugeDatapoint(metricName, dataPoint); + } else if (dropwizardMetric instanceof HashMap) { + HashMap<?, ?> itemsMap = (HashMap<?, ?>) dropwizardMetric; + for (Object item : itemsMap.keySet()) { + if (itemsMap.get(item) instanceof Number) { + GaugeSnapshot.GaugeDataPointSnapshot dataPoint = + createGaugeDatapoint( + ((Number) itemsMap.get(item)).doubleValue(), + labels.merge(Labels.of("item", (String) item))); + collectGaugeDatapoint(metricName, dataPoint); + } + } + } + } + + /** + * Create a {@link io.prometheus.metrics.model.snapshots.CounterSnapshot.CounterDataPointSnapshot} + * with labels + * + * @param value metric value + * @param labels set of name/values labels + */ + public CounterSnapshot.CounterDataPointSnapshot createCounterDatapoint( + double value, Labels labels) { + return CounterSnapshot.CounterDataPointSnapshot.builder().value(value).labels(labels).build(); + } + + /** + * Create a {@link io.prometheus.metrics.model.snapshots.GaugeSnapshot.GaugeDataPointSnapshot} + * with labels + * + * @param value metric value + * @param labels set of name/values labels + */ + public GaugeSnapshot.GaugeDataPointSnapshot createGaugeDatapoint(double value, Labels labels) { + return GaugeSnapshot.GaugeDataPointSnapshot.builder().value(value).labels(labels).build(); + } + + /** + * Collects {@link io.prometheus.metrics.model.snapshots.CounterSnapshot.CounterDataPointSnapshot} + * and appends to existing metric or create new metric if name does not exist + * + * @param metricName Name of metric + * @param dataPoint Counter datapoint to be collected + */ + public void collectCounterDatapoint( + String metricName, CounterSnapshot.CounterDataPointSnapshot dataPoint) { + if (!metricCounters.containsKey(metricName)) { + metricCounters.put(metricName, new ArrayList<>()); + } + metricCounters.get(metricName).add(dataPoint); + } + + /** + * Collects {@link io.prometheus.metrics.model.snapshots.GaugeSnapshot.GaugeDataPointSnapshot} and + * appends to existing metric or create new metric if name does not exist + * + * @param metricName Name of metric + * @param dataPoint Gauge datapoint to be collected + */ + public void collectGaugeDatapoint( + String metricName, GaugeSnapshot.GaugeDataPointSnapshot dataPoint) { + if (!metricGauges.containsKey(metricName)) { + metricGauges.put(metricName, new ArrayList<>()); + } + metricGauges.get(metricName).add(dataPoint); + } + + /** + * Returns an immutable {@link MetricSnapshots} from the {@link + * io.prometheus.metrics.model.snapshots.DataPointSnapshot}s collected from the registry + */ + public MetricSnapshots collect() { Review Comment: Order doesn't matter. The constructor of `MetricSnapshots` gets sorted by the Metric name. See this [constructor](https://github.com/prometheus/client_java/blob/c0a38270c021e4d63998a98a68bacf2b6f32ace5/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/MetricSnapshots.java#L40). But with metrics, it shouldn't matter anyways although I agree, it can be annoying. All the metrics would be aggregated on a Grafana level with prometheus queries. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
