io.druid.java.util.metrics.JvmThreadsMonitor.java Source code

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Here is the source code for io.druid.java.util.metrics.JvmThreadsMonitor.java

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/*
 * Licensed to Metamarkets Group Inc. (Metamarkets) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. Metamarkets 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 io.druid.java.util.metrics;

import com.google.common.base.Preconditions;
import com.google.common.collect.ImmutableMap;
import io.druid.java.util.emitter.service.ServiceEmitter;
import io.druid.java.util.emitter.service.ServiceMetricEvent;

import java.lang.management.ManagementFactory;
import java.lang.management.ThreadMXBean;
import java.util.Map;

public class JvmThreadsMonitor extends FeedDefiningMonitor {
    private final Map<String, String[]> dimensions;

    private int lastLiveThreads = 0;
    private long lastStartedThreads = 0;

    public JvmThreadsMonitor(Map<String, String[]> dimensions, String feed) {
        super(feed);
        Preconditions.checkNotNull(dimensions);
        this.dimensions = ImmutableMap.copyOf(dimensions);
    }

    @Override
    public boolean doMonitor(ServiceEmitter emitter) {
        ThreadMXBean threadBean = ManagementFactory.getThreadMXBean();

        final ServiceMetricEvent.Builder builder = builder();
        MonitorUtils.addDimensionsToBuilder(builder, dimensions);

        // Because between next two calls on ThreadMXBean new threads can be started we can observe some inconsistency
        // in counters values and finished counter could be even negative
        int newLiveThreads = threadBean.getThreadCount();
        long newStartedThreads = threadBean.getTotalStartedThreadCount();

        long startedThreadsDiff = newStartedThreads - lastStartedThreads;

        emitter.emit(builder.build("jvm/threads/started", startedThreadsDiff));
        emitter.emit(builder.build("jvm/threads/finished", lastLiveThreads + startedThreadsDiff - newLiveThreads));
        emitter.emit(builder.build("jvm/threads/live", newLiveThreads));
        emitter.emit(builder.build("jvm/threads/liveDaemon", threadBean.getDaemonThreadCount()));

        emitter.emit(builder.build("jvm/threads/livePeak", threadBean.getPeakThreadCount()));
        threadBean.resetPeakThreadCount();

        lastStartedThreads = newStartedThreads;
        lastLiveThreads = newLiveThreads;

        return true;
    }
}