io.micrometer.core.instrument.binder.jvm.JvmHeapPressureMetrics Maven / Gradle / Ivy

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Core module of Micrometer containing instrumentation API and implementation
There is a newer version: 1.13.2
/*
 * Copyright 2020 VMware, Inc.
 *
 * Licensed 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
 *
 * https://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 io.micrometer.core.instrument.binder.jvm;

import com.sun.management.GarbageCollectionNotificationInfo;
import com.sun.management.GcInfo;
import io.micrometer.core.instrument.Gauge;
import io.micrometer.core.instrument.MeterRegistry;
import io.micrometer.core.instrument.Tag;
import io.micrometer.core.instrument.binder.BaseUnits;
import io.micrometer.core.instrument.binder.MeterBinder;
import io.micrometer.core.instrument.distribution.TimeWindowSum;
import io.micrometer.core.lang.NonNull;

import javax.management.ListenerNotFoundException;
import javax.management.NotificationEmitter;
import javax.management.NotificationListener;
import javax.management.openmbean.CompositeData;
import java.lang.management.GarbageCollectorMXBean;
import java.lang.management.ManagementFactory;
import java.lang.management.MemoryPoolMXBean;
import java.lang.management.MemoryUsage;
import java.time.Duration;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.CopyOnWriteArrayList;
import java.util.concurrent.atomic.AtomicReference;
import java.util.stream.Collectors;

import static java.util.Collections.emptyList;

/**
 * Provides methods to access measurements of low pool memory and heavy GC overhead as
 * described in TeamCity's
 * Memory Monitor.
 *
 * @author Jon Schneider
 * @since 1.4.0
 */
public class JvmHeapPressureMetrics implements MeterBinder, AutoCloseable {

    private final Iterable tags;

    private final List notificationListenerCleanUpRunnables = new CopyOnWriteArrayList<>();

    private final long startOfMonitoring = System.nanoTime();

    private final Duration lookback;

    private final TimeWindowSum gcPauseSum;

    private final AtomicReference lastLongLivedPoolUsageAfterGc = new AtomicReference<>(0.0);

    private final Set longLivedPoolNames;

    public JvmHeapPressureMetrics() {
        this(emptyList(), Duration.ofMinutes(5), Duration.ofMinutes(1));
    }

    public JvmHeapPressureMetrics(Iterable tags, Duration lookback, Duration testEvery) {
        this.tags = tags;
        this.lookback = lookback;
        this.gcPauseSum = new TimeWindowSum((int) lookback.dividedBy(testEvery.toMillis()).toMillis(), testEvery);

        longLivedPoolNames = JvmMemory.getLongLivedHeapPools().map(MemoryPoolMXBean::getName)
                .collect(Collectors.toSet());

        monitor();
    }

    @Override
    public void bindTo(@NonNull MeterRegistry registry) {
        if (!longLivedPoolNames.isEmpty()) {
            Gauge.builder("jvm.memory.usage.after.gc", lastLongLivedPoolUsageAfterGc, AtomicReference::get).tags(tags)
                    .tag("area", "heap").tag("pool", "long-lived")
                    .description(
                            "The percentage of long-lived heap pool used after the last GC event, in the range [0..1]")
                    .baseUnit(BaseUnits.PERCENT).register(registry);
        }

        Gauge.builder("jvm.gc.overhead", gcPauseSum, pauseSum -> {
            double overIntervalMillis = Math.min(System.nanoTime() - startOfMonitoring, lookback.toNanos()) / 1e6;
            return gcPauseSum.poll() / overIntervalMillis;
        }).tags(tags).description(
                "An approximation of the percent of CPU time used by GC activities over the last lookback period or since monitoring began, whichever is shorter, in the range [0..1]")
                .baseUnit(BaseUnits.PERCENT).register(registry);
    }

    private void monitor() {
        for (GarbageCollectorMXBean mbean : ManagementFactory.getGarbageCollectorMXBeans()) {
            if (!(mbean instanceof NotificationEmitter)) {
                continue;
            }
            NotificationListener notificationListener = (notification, ref) -> {
                CompositeData cd = (CompositeData) notification.getUserData();
                GarbageCollectionNotificationInfo notificationInfo = GarbageCollectionNotificationInfo.from(cd);

                String gcCause = notificationInfo.getGcCause();
                GcInfo gcInfo = notificationInfo.getGcInfo();
                long duration = gcInfo.getDuration();

                if (!JvmMemory.isConcurrentPhase(gcCause, notificationInfo.getGcName())) {
                    gcPauseSum.record(duration);
                }

                Map after = gcInfo.getMemoryUsageAfterGc();

                if (!longLivedPoolNames.isEmpty()) {
                    final long usedAfter = longLivedPoolNames.stream().mapToLong(pool -> after.get(pool).getUsed())
                            .sum();
                    double maxAfter = longLivedPoolNames.stream().mapToLong(pool -> after.get(pool).getMax()).sum();
                    lastLongLivedPoolUsageAfterGc.set(usedAfter / maxAfter);
                }
            };
            NotificationEmitter notificationEmitter = (NotificationEmitter) mbean;
            notificationEmitter.addNotificationListener(notificationListener, notification -> notification.getType()
                    .equals(GarbageCollectionNotificationInfo.GARBAGE_COLLECTION_NOTIFICATION), null);
            notificationListenerCleanUpRunnables.add(() -> {
                try {
                    notificationEmitter.removeNotificationListener(notificationListener);
                }
                catch (ListenerNotFoundException ignore) {
                }
            });
        }
    }

    @Override
    public void close() {
        notificationListenerCleanUpRunnables.forEach(Runnable::run);
    }

}