org.apache.hama.util.ClusterUtil.java Source code

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Here is the source code for org.apache.hama.util.ClusterUtil.java

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/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF 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 org.apache.hama.util;

import java.io.IOException;
import java.util.List;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configuration;
import org.apache.hama.HamaConfiguration;
import org.apache.hama.bsp.BSPMaster;
import org.apache.hama.bsp.GroomServer;

public class ClusterUtil {
    private static final Log LOG = LogFactory.getLog(ClusterUtil.class);

    /**
     * Data Structure to hold GroomServer Thread and GroomServer instance
     */
    public static class GroomServerThread extends Thread {
        private final GroomServer groomServer;

        public GroomServerThread(final GroomServer r, final int index) {
            super(r, "GroomServer:" + index);
            this.groomServer = r;
        }

        /** @return the groom server */
        public GroomServer getGroomServer() {
            return this.groomServer;
        }

        /**
         * Block until the groom server has come online, indicating it is ready to
         * be used.
         */
        public void waitForServerOnline() {
            while (!groomServer.isRunning()) {
                try {
                    Thread.sleep(1000);
                } catch (InterruptedException e) {
                    // continue waiting
                }
            }
        }
    }

    /**
     * Creates a {@link GroomServerThread}. Call 'start' on the returned thread to
     * make it run.
     * 
     * @param c Configuration to use.
     * @param hrsc Class to create.
     * @param index Used distingushing the object returned.
     * @throws IOException
     * @return Groom server added.
     */
    public static ClusterUtil.GroomServerThread createGroomServerThread(final Configuration c,
            final Class<? extends GroomServer> hrsc, final int index) throws IOException {
        GroomServer server;
        try {
            server = hrsc.getConstructor(Configuration.class).newInstance(c);
        } catch (Exception e) {
            IOException ioe = new IOException();
            ioe.initCause(e);
            throw ioe;
        }
        return new ClusterUtil.GroomServerThread(server, index);
    }

    /**
     * Start the cluster.
     * 
     * @param m the BSP master
     * @param conf cluster configuration to be used
     * @param groomservers list of threads holding groom servers
     * @return Address to use contacting master.
     * @throws InterruptedException
     * @throws IOException
     */
    public static String startup(final BSPMaster m, final List<ClusterUtil.GroomServerThread> groomservers,
            Configuration conf) throws IOException, InterruptedException {
        if (m != null) {
            BSPMaster.startMaster((HamaConfiguration) conf);
        }

        if (groomservers != null) {
            for (ClusterUtil.GroomServerThread t : groomservers) {
                t.start();
            }
        }

        return m == null ? null : BSPMaster.getAddress(conf).getHostName();
    }

    public static void shutdown(BSPMaster master, List<GroomServerThread> groomThreads, Configuration conf) {
        LOG.debug("Shutting down HAMA Cluster");
        // TODO:
    }
}