org.apache.flink.runtime.rest.handler.job.metrics.AbstractMetricsHandler Maven / Gradle / Ivy
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* 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,
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package org.apache.flink.runtime.rest.handler.job.metrics;
import org.apache.flink.api.common.time.Time;
import org.apache.flink.runtime.rest.handler.AbstractRestHandler;
import org.apache.flink.runtime.rest.handler.HandlerRequest;
import org.apache.flink.runtime.rest.handler.RestHandlerException;
import org.apache.flink.runtime.rest.handler.legacy.metrics.MetricFetcher;
import org.apache.flink.runtime.rest.handler.legacy.metrics.MetricStore;
import org.apache.flink.runtime.rest.messages.EmptyRequestBody;
import org.apache.flink.runtime.rest.messages.MessageHeaders;
import org.apache.flink.runtime.rest.messages.MessageParameters;
import org.apache.flink.runtime.rest.messages.job.metrics.Metric;
import org.apache.flink.runtime.rest.messages.job.metrics.MetricCollectionResponseBody;
import org.apache.flink.runtime.rest.messages.job.metrics.MetricsFilterParameter;
import org.apache.flink.runtime.webmonitor.RestfulGateway;
import org.apache.flink.runtime.webmonitor.retriever.GatewayRetriever;
import javax.annotation.Nonnull;
import javax.annotation.Nullable;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.CompletableFuture;
import java.util.stream.Collectors;
import static java.util.Objects.requireNonNull;
/**
* Request handler that returns for a given task a list of all available metrics or the values for a set of metrics.
*
* If the query parameters do not contain a "get" parameter the list of all metrics is returned.
* {@code {"available": [ { "name" : "X", "id" : "X" } ] } }
*
*
If the query parameters do contain a "get" parameter, a comma-separated list of metric names is expected as a value.
* {@code /metrics?get=X,Y}
* The handler will then return a list containing the values of the requested metrics.
* {@code [ { "id" : "X", "value" : "S" }, { "id" : "Y", "value" : "T" } ] }
*
* @param Type of the concrete {@link MessageParameters}
*/
public abstract class AbstractMetricsHandler extends
AbstractRestHandler {
private final MetricFetcher metricFetcher;
public AbstractMetricsHandler(
GatewayRetriever leaderRetriever,
Time timeout,
Map headers,
MessageHeaders messageHeaders,
MetricFetcher metricFetcher) {
super(leaderRetriever, timeout, headers, messageHeaders);
this.metricFetcher = requireNonNull(metricFetcher, "metricFetcher must not be null");
}
@Override
protected final CompletableFuture handleRequest(
@Nonnull HandlerRequest request,
@Nonnull RestfulGateway gateway) throws RestHandlerException {
metricFetcher.update();
final MetricStore.ComponentMetricStore componentMetricStore = getComponentMetricStore(
request,
metricFetcher.getMetricStore());
if (componentMetricStore == null || componentMetricStore.metrics == null) {
return CompletableFuture.completedFuture(
new MetricCollectionResponseBody(Collections.emptyList()));
}
final Set requestedMetrics = new HashSet<>(request.getQueryParameter(
MetricsFilterParameter.class));
if (requestedMetrics.isEmpty()) {
return CompletableFuture.completedFuture(
new MetricCollectionResponseBody(getAvailableMetrics(componentMetricStore)));
} else {
final List metrics = getRequestedMetrics(componentMetricStore, requestedMetrics);
return CompletableFuture.completedFuture(new MetricCollectionResponseBody(metrics));
}
}
/**
* Returns the {@link MetricStore.ComponentMetricStore} that should be queried for metrics.
*/
@Nullable
protected abstract MetricStore.ComponentMetricStore getComponentMetricStore(
HandlerRequest request,
MetricStore metricStore);
private static List getAvailableMetrics(MetricStore.ComponentMetricStore componentMetricStore) {
return componentMetricStore.metrics
.keySet()
.stream()
.map(Metric::new)
.collect(Collectors.toList());
}
private static List getRequestedMetrics(
MetricStore.ComponentMetricStore componentMetricStore,
Set requestedMetrics) throws RestHandlerException {
final List metrics = new ArrayList<>(requestedMetrics.size());
for (final String requestedMetric : requestedMetrics) {
final String value = componentMetricStore.getMetric(requestedMetric, null);
if (value != null) {
metrics.add(new Metric(requestedMetric, value));
}
}
return metrics;
}
}