org.eclipse.gyrex.cloud.internal.zk.ZooKeeperServerApplication.java Source code

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Here is the source code for org.eclipse.gyrex.cloud.internal.zk.ZooKeeperServerApplication.java

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/*******************************************************************************
 * Copyright (c) 2011, 2012 AGETO Service GmbH and others.
 * All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
 * and is available at http://www.eclipse.org/legal/epl-v10.html.
 *
 * Contributors:
 *     Gunnar Wagenknecht - initial API and implementation
 *******************************************************************************/
package org.eclipse.gyrex.cloud.internal.zk;

import java.io.File;
import java.net.InetSocketAddress;
import java.util.Map;

import org.eclipse.gyrex.boot.internal.app.ServerApplication;
import org.eclipse.gyrex.cloud.internal.CloudActivator;
import org.eclipse.gyrex.cloud.internal.CloudDebug;
import org.eclipse.gyrex.common.internal.applications.BaseApplication;
import org.eclipse.gyrex.server.Platform;

import org.eclipse.core.runtime.IPath;

import org.apache.commons.lang.exception.ExceptionUtils;
import org.apache.zookeeper.server.PurgeTxnLog;
import org.apache.zookeeper.server.ZooKeeperServer;
import org.apache.zookeeper.server.persistence.FileTxnSnapLog;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * An application which starts a ZooKeeper server.
 */
public class ZooKeeperServerApplication extends BaseApplication {

    private static final Logger LOG = LoggerFactory.getLogger(ZooKeeperServerApplication.class);

    static volatile ZooKeeperGateApplication connectedGateApplication;

    private ZooKeeperServer zkServer;
    private Object factory;

    /**
     * Creates a new instance.
     */
    public ZooKeeperServerApplication() {
        debug = CloudDebug.zooKeeperServer;
    }

    private Object createFactory(final InetSocketAddress socketAddress, final int maxClientConnextions)
            throws Exception {
        // try ZooKeeper 3.4 way
        try {
            return CloudActivator.getInstance().getBundle()
                    .loadClass("org.apache.zookeeper.server.ServerCnxnFactory")
                    .getMethod("createFactory", InetSocketAddress.class, Integer.TYPE)
                    .invoke(null, socketAddress, maxClientConnextions);
        } catch (final Exception e) {
            LOG.debug("ZooKeeper 3.4 API not available. Falling back to ZooKeeper 3.3 API.");
        }

        // fallback to ZooKeeper 3.3 way
        // FIXME: remove this once we upgraded (bug 361524)
        try {
            return CloudActivator.getInstance().getBundle()
                    .loadClass("org.apache.zookeeper.server.NIOServerCnxn$Factory")
                    .getConstructor(InetSocketAddress.class, Integer.TYPE)
                    .newInstance(socketAddress, maxClientConnextions);
        } catch (final Exception e) {
            throw new IllegalStateException("Unable to create ZooKeeper NIO Factory using 3.3 API.", e);
        }
    }

    @Override
    protected void doStart(final Map arguments) throws Exception {
        try {
            runStandaloneEmbedded();
        } catch (final Exception e) {
            // shutdown the whole server
            if (Platform.inDevelopmentMode()) {
                ServerApplication.shutdown(new Exception(
                        "Could not start the embedded ZooKeeper server. " + ExceptionUtils.getRootCauseMessage(e),
                        e));
            } else {
                LOG.error("Unable to start embedded ZooKeeper. {}", ExceptionUtils.getRootCauseMessage(e), e);
            }
            throw new StartAbortedException();
        }
    }

    @Override
    protected Object doStop() {
        // stop any running gate application first
        final ZooKeeperGateApplication gateApp = connectedGateApplication;
        if (null != gateApp) {
            connectedGateApplication = null;
            try {
                gateApp.stop();
            } catch (final Exception ignored) {
                // ignore
            }
        }

        // wait a little bit to let the server handle pending disconnects
        try {
            if (CloudDebug.zooKeeperServer) {
                LOG.debug("Preparing for ZooKeeper shutdown...");
            }
            Thread.sleep(250L);
        } catch (final InterruptedException e) {
            Thread.currentThread().interrupt();
        }

        // shutdown standalone server if still running
        if (null != factory) {
            if (CloudDebug.zooKeeperServer) {
                LOG.debug("Shutting down standalone ZooKeeper server...");
            }
            try {
                factory.getClass().getMethod("shutdown").invoke(factory);
            } catch (final Exception e) {
                LOG.error("Error stopping server {}. {}",
                        new Object[] { factory, ExceptionUtils.getRootCauseMessage(e), e });
            }
            factory = null;

            if (zkServer.isRunning()) {
                zkServer.shutdown();
            }
            zkServer = null;

            LOG.info("ZooKeeper server stopped.");
        }

        return EXIT_OK;
    }

    @Override
    protected Logger getLogger() {
        return LOG;
    }

    private void runStandaloneEmbedded() throws Exception {
        // disable LOG4J JMX stuff
        System.setProperty("zookeeper.jmx.log4j.disable", Boolean.TRUE.toString());

        // get directories
        final IPath zkBase = Platform.getInstanceLocation().append("zookeeper");
        final File dataDir = zkBase.append("logs").toFile();
        final File snapDir = zkBase.toFile();

        // clean old logs
        PurgeTxnLog.purge(dataDir, snapDir, 3);

        // create standalone server
        zkServer = new ZooKeeperServer();
        zkServer.setTxnLogFactory(new FileTxnSnapLog(dataDir, snapDir));

        // rely on defaults for the following values
        zkServer.setTickTime(ZooKeeperServer.DEFAULT_TICK_TIME);
        zkServer.setMinSessionTimeout(2 * ZooKeeperServer.DEFAULT_TICK_TIME);
        zkServer.setMaxSessionTimeout(10 * ZooKeeperServer.DEFAULT_TICK_TIME);

        // start factory on default port
        factory = createFactory(new InetSocketAddress(2181), 10);

        // start server
        LOG.info("Starting ZooKeeper standalone server.");
        factory.getClass().getMethod("startup", ZooKeeperServer.class).invoke(factory, zkServer);
    }
}