org.apache.hama.bsp.message.HadoopMessageManagerImpl.java Source code

Introduction

Here is the source code for org.apache.hama.bsp.message.HadoopMessageManagerImpl.java

Source

/**
 * 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.bsp.message;

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

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.io.Writable;
import org.apache.hadoop.ipc.RPC;
import org.apache.hadoop.ipc.RPC.Server;
import org.apache.hama.bsp.BSPMessageBundle;
import org.apache.hama.bsp.BSPPeer;
import org.apache.hama.bsp.BSPPeerImpl;
import org.apache.hama.bsp.TaskAttemptID;
import org.apache.hama.bsp.message.compress.BSPCompressedBundle;
import org.apache.hama.ipc.HamaRPCProtocolVersion;
import org.apache.hama.util.LRUCache;

/**
 * Implementation of the {@link HadoopMessageManager}.
 * 
 */
public final class HadoopMessageManagerImpl<M extends Writable> extends CompressableMessageManager<M>
        implements HadoopMessageManager<M> {

    private static final Log LOG = LogFactory.getLog(HadoopMessageManagerImpl.class);

    private Server server = null;

    private LRUCache<InetSocketAddress, HadoopMessageManager<M>> peersLRUCache = null;

    @SuppressWarnings("serial")
    @Override
    public final void init(TaskAttemptID attemptId, BSPPeer<?, ?, ?, ?, M> peer, Configuration conf,
            InetSocketAddress peerAddress) {
        super.init(attemptId, peer, conf, peerAddress);
        super.initCompression(conf);
        //?RPC Server
        startRPCServer(conf, peerAddress);
        peersLRUCache = new LRUCache<InetSocketAddress, HadoopMessageManager<M>>(maxCachedConnections) {
            @Override
            protected final boolean removeEldestEntry(
                    Map.Entry<InetSocketAddress, HadoopMessageManager<M>> eldest) {
                if (size() > this.capacity) {
                    HadoopMessageManager<M> proxy = eldest.getValue();
                    RPC.stopProxy(proxy);
                    return true;
                }
                return false;
            }
        };
    }

    private final void startRPCServer(Configuration conf, InetSocketAddress peerAddress) {
        try {
            this.server = RPC.getServer(this, peerAddress.getHostName(), peerAddress.getPort(), conf);
            LOG.debug("server : " + server);
            server.start();
            LOG.info(" BSPPeer address:" + peerAddress.getHostName() + " port:" + peerAddress.getPort());
        } catch (IOException e) {
            LOG.error("Fail to start RPC server!", e);
            throw new RuntimeException("RPC Server could not be launched!");
        }
    }

    @Override
    public final void close() {
        super.close();
        if (server != null) {
            server.stop();
        }
    }

    @Override
    public final void transfer(InetSocketAddress addr, BSPMessageBundle<M> bundle) throws IOException {
        HadoopMessageManager<M> bspPeerConnection = this.getBSPPeerConnection(addr);
        if (bspPeerConnection == null) {
            throw new IllegalArgumentException("Can not find " + addr.toString() + " to transfer messages to!");
        } else {
            if (compressor != null && (bundle.getApproximateSize() > conf
                    .getLong("hama.messenger.compression.threshold", 1048576))) {
                BSPCompressedBundle compMsgBundle = compressor.compressBundle(bundle);
                bspPeerConnection.put(compMsgBundle);
                peer.incrementCounter(BSPPeerImpl.PeerCounter.COMPRESSED_MESSAGES, 1L);
            } else {
                bspPeerConnection.put(bundle);
            }
        }
    }

    /**
     * @param addr, socket address to which BSP Peer Connection will be
     *          established
     * @return BSP Peer Connection, tried to return cached connection, else
     *         returns a new connection and caches it
     * @throws IOException
     */
    @SuppressWarnings("unchecked")
    protected final HadoopMessageManager<M> getBSPPeerConnection(InetSocketAddress addr) throws IOException {
        HadoopMessageManager<M> bspPeerConnection;
        if (!peersLRUCache.containsKey(addr)) {
            bspPeerConnection = (HadoopMessageManager<M>) RPC.getProxy(HadoopMessageManager.class,
                    HamaRPCProtocolVersion.versionID, addr, this.conf);
            peersLRUCache.put(addr, bspPeerConnection);
        } else {
            bspPeerConnection = peersLRUCache.get(addr);
        }
        return bspPeerConnection;
    }

    @Override
    public final void put(M msg) throws IOException {
        loopBackMessage(msg);
    }

    @Override
    public final void put(BSPMessageBundle<M> messages) throws IOException {
        loopBackMessages(messages);
    }

    @Override
    public final void put(BSPCompressedBundle compMsgBundle) throws IOException {
        BSPMessageBundle<M> bundle = compressor.decompressBundle(compMsgBundle);
        loopBackMessages(bundle);
    }

    @Override
    public final long getProtocolVersion(String arg0, long arg1) throws IOException {
        return versionID;
    }

}