JmxTransExporter.java

/*
 * Copyright (c) 2010-2013 the original author or authors
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 */
package org.jmxtrans.agent;

import java.lang.management.ManagementFactory;
import java.math.BigInteger;
import java.sql.Timestamp;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.logging.Level;

import javax.management.MBeanServer;

import org.jmxtrans.agent.util.GcdCalculator;
import org.jmxtrans.agent.util.logging.Logger;

/**
 * @author <a href="mailto:cleclerc@cloudbees.com">Cyrille Le Clerc</a>
 */
public class JmxTransExporter {
    private final Logger logger = Logger.getLogger(getClass().getName());
    private ThreadFactory threadFactory = new ThreadFactory() {
        final AtomicInteger counter = new AtomicInteger();

        @Override
        public Thread newThread(Runnable r) {
            Thread thread = Executors.defaultThreadFactory().newThread(r);
            thread.setDaemon(true);
            thread.setName("jmxtrans-agent-" + counter.incrementAndGet());
            return thread;
        }
    };
    private ScheduledExecutorService scheduledExecutorService;
    private MBeanServer mbeanServer = ManagementFactory.getPlatformMBeanServer();
    private ScheduledFuture scheduledFuture;
    private JmxTransConfigurationLoader configLoader;
    private volatile JmxTransExporterConfiguration config;
    private volatile List<TimeTrackingCollector> collectors;
    private volatile long runIntervalMillis;

    public JmxTransExporter(JmxTransConfigurationLoader configLoader) {
        this.configLoader = configLoader;
        loadNewConfiguration();
    }

    private void loadNewConfiguration() {
        this.config = configLoader.loadConfiguration();
        logger.finest("Configuration loaded: " + config);
        this.collectors = createTimeTrackingCollectors();
        this.runIntervalMillis = calculateRunIntervalMillis();
    }


    private List<TimeTrackingCollector> createTimeTrackingCollectors() {
        List<TimeTrackingCollector> newCollectors = new ArrayList<>();
        for (Query q : config.getQueries()) {
            TimeTrackingCollector timeTrackingCollector = createTimeTrackingCollector(q, q.getCollectIntervalOverrideOrNull());
            newCollectors.add(timeTrackingCollector);
        }
        for (Invocation i : config.getInvocations()) {
            TimeTrackingCollector timeTrackingCollector = createTimeTrackingCollector(i, i.getCollectIntervalOverrideOrNull());
            newCollectors.add(timeTrackingCollector);
        }
        return newCollectors;
    }

    private TimeTrackingCollector createTimeTrackingCollector(Collector collector, Integer collectIntervalOverride) {
        int actualCollectInterval = collectIntervalOverride != null ? collectIntervalOverride : config.getCollectInterval();
        TimeTrackingCollector timeTrackingCollector = new TimeTrackingCollector(collector, TimeUnit.MILLISECONDS.convert(actualCollectInterval, config.getCollectIntervalTimeUnit()));
        return timeTrackingCollector;
    }

    private long calculateRunIntervalMillis() {
        // Use the greatest common divisor of the collect intervals to get period in which we need to collect
        if (collectors.isEmpty()) {
            // Ensure that we trigger runs even if there are no queries so that config refresh works.
            return config.getCollectInterval();
        }
        List<Long> collectIntervals = new ArrayList<>();
        for (TimeTrackingCollector c : collectors) {
            collectIntervals.add(c.getCollectIntervalMillis());
        }
        return GcdCalculator.gcd(collectIntervals);
    }

    public void start() {
        if (logger.isLoggable(Level.FINER)) {
            logger.fine("starting " + this.toString() + " ...");
        } else {
            logger.fine("starting " + getClass().getName() + " ...");
        }

        if (scheduledExecutorService != null || scheduledFuture != null)
            throw new IllegalArgumentException("Exporter is already started: scheduledExecutorService=" + scheduledExecutorService + ", scheduledFuture=" + scheduledFuture);

        scheduledExecutorService = Executors.newScheduledThreadPool(1, threadFactory);

        if (config.getResultNameStrategy() == null)
            throw new IllegalStateException("resultNameStrategy is not defined, jmxTransExporter is not properly initialised");

        scheduledFuture = scheduledExecutorService.scheduleWithFixedDelay(new Runnable() {
            @Override
            public void run() {
                collectAndExport();
            }
        }, runIntervalMillis / 2, runIntervalMillis, TimeUnit.MILLISECONDS);

        if (config.getConfigReloadInterval() >= 0) {
            Runnable runnable = new Runnable() {
                private final Logger logger = Logger.getLogger(JmxTransExporter.class.getName() + ".reloader");
                private long lastModified = configLoader.lastModified();

                @Override
                public void run() {
                    long newLastModified = configLoader.lastModified();
                    if (newLastModified == 0L) {
                        if (logger.isLoggable(Level.FINER))
                            logger.finer("Don't reload lastModified=" + lastModified + " / " + new Timestamp(lastModified) +
                                    ", newLastModified=" + newLastModified);
                        // ignore new config not found
                    } else if (newLastModified > lastModified) {
                        logger.info("jmxtrans-agent configuration has changed. Reload " + configLoader);
                        if (logger.isLoggable(Level.FINER))
                            logger.finer("Reload lastModified=" + lastModified + " / " + new Timestamp(lastModified) +
                                ", newLastModified=" + newLastModified + " / " + new Timestamp(newLastModified));

                        lastModified = newLastModified;
                        stop();
                        loadNewConfiguration();
                        start();
                    } else {
                        if (logger.isLoggable(Level.FINER))
                            logger.finer("Don't reload lastModified=" + lastModified + " / " + new Timestamp(lastModified) +
                                    ", newLastModified=" + newLastModified + " / " + new Timestamp(newLastModified));

                        // ignore, config not modified
                    }

                }
            };
            int configReloadIntervalInSecs = Math.max(config.getConfigReloadInterval(), 5);
            if (logger.isLoggable(Level.INFO))
                logger.info("Configuration reload interval: " + configReloadIntervalInSecs + "secs");
            scheduledExecutorService.scheduleWithFixedDelay(runnable, 0, configReloadIntervalInSecs, TimeUnit.SECONDS);
        }

        logger.fine(getClass().getName() + " started");
    }

    public void stop() {
        // cancel jobs
        if (scheduledFuture != null) {
            scheduledFuture.cancel(true);
            scheduledFuture = null;
        }
        scheduledExecutorService.shutdown();

        // one last export
        collectAndExport();

        // wait for stop
        try {
            scheduledExecutorService.awaitTermination(runIntervalMillis, TimeUnit.MILLISECONDS);

        } catch (InterruptedException e) {
            throw new IllegalStateException(e);
        }
        scheduledExecutorService = null;

        config.getOutputWriter().preDestroy();

        logger.info(getClass().getName() + " stopped.");

    }

    protected void collectAndExport() {
        OutputWriter outputWriter = config.getOutputWriter();
        try {
            outputWriter.preCollect();
            for (TimeTrackingCollector collector : collectors) {
                try {
                    collector.collectIfEnoughTimeHasPassed(mbeanServer, outputWriter);
                } catch (Exception e) {
                    logger.log(Level.WARNING, "Ignore exception collecting with collector " + collector, e);
                }
            }
            outputWriter.postCollect();
        } catch (Exception e) {
            logger.log(Level.WARNING, "Ignore exception flushing metrics ", e);
        }
    }

    @Override
    public String toString() {
        return "JmxTransExporter{" +
                ", configuration=" + config +
                '}';
    }

}