org.apache.hadoop.hdfs.server.datanode.BlockPoolManager.java Source code

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Here is the source code for org.apache.hadoop.hdfs.server.datanode.BlockPoolManager.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.hadoop.hdfs.server.datanode;

import com.google.common.base.Preconditions;
import com.google.common.collect.Maps;
import java.util.*;
import java.util.concurrent.CopyOnWriteArrayList;

import org.apache.commons.logging.Log;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hdfs.DFSUtil;
import org.apache.hadoop.security.UserGroupInformation;

import java.io.IOException;
import java.net.InetSocketAddress;
import java.security.PrivilegedExceptionAction;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

/**
 * Manages the BPOfferService objects for the data node.
 * Creation, removal, starting, stopping, shutdown on BPOfferService
 * objects must be done via APIs in this class.
 */
@InterfaceAudience.Private
class BlockPoolManager {
    private static final Log LOG = DataNode.LOG;

    private final Map<String, BPOfferService> bpByNameserviceId = Maps.newHashMap();
    private final Map<String, BPOfferService> bpByBlockPoolId = Maps.newHashMap();
    private final List<BPOfferService> offerServices = new CopyOnWriteArrayList<>();

    private final DataNode dn;

    //This lock is used only to ensure exclusion of refreshNamenodes
    private final Object refreshNamenodesLock = new Object();

    BlockPoolManager(DataNode dn) {
        this.dn = dn;
    }

    synchronized void addBlockPool(BPOfferService bpos) {
        Preconditions.checkArgument(offerServices.contains(bpos), "Unknown BPOS: %s", bpos);
        if (bpos.getBlockPoolId() == null) {
            throw new IllegalArgumentException("Null blockpool id");
        }
        bpByBlockPoolId.put(bpos.getBlockPoolId(), bpos);
    }

    /**
     * Returns a list of BPOfferService objects. The underlying list
     * implementation is a CopyOnWriteArrayList so it can be safely
     * iterated while BPOfferServices are being added or removed.
     *
     * Caution: The BPOfferService returned could be shutdown any time.
     */
    synchronized List<BPOfferService> getAllNamenodeThreads() {
        return Collections.unmodifiableList(offerServices);
    }

    synchronized BPOfferService get(String bpid) {
        return bpByBlockPoolId.get(bpid);
    }

    synchronized void remove(BPOfferService t) {
        offerServices.remove(t);
        if (t.hasBlockPoolId()) {
            // It's possible that the block pool never successfully registered
            // with any NN, so it was never added it to this map
            bpByBlockPoolId.remove(t.getBlockPoolId());
        }

        boolean removed = false;
        for (Iterator<BPOfferService> it = bpByNameserviceId.values().iterator(); it.hasNext() && !removed;) {
            BPOfferService bpos = it.next();
            if (bpos == t) {
                it.remove();
                LOG.info("Removed " + bpos);
                removed = true;
            }
        }

        if (!removed) {
            LOG.warn("Couldn't remove BPOS " + t + " from bpByNameserviceId map");
        }
    }

    void shutDownAll(List<BPOfferService> bposList) throws InterruptedException {
        for (BPOfferService bpos : bposList) {
            bpos.stop(); //interrupts the threads
        }
        //now join
        for (BPOfferService bpos : bposList) {
            bpos.join();
        }
    }

    synchronized void startAll() throws IOException {
        try {
            UserGroupInformation.getLoginUser().doAs(new PrivilegedExceptionAction<Object>() {
                @Override
                public Object run() throws Exception {
                    for (BPOfferService bpos : offerServices) {
                        bpos.start();
                    }
                    return null;
                }
            });
        } catch (InterruptedException ex) {
            IOException ioe = new IOException();
            ioe.initCause(ex.getCause());
            throw ioe;
        }
    }

    void joinAll() {
        for (BPOfferService bpos : this.getAllNamenodeThreads()) {
            bpos.join();
        }
    }

    void refreshNamenodes(Configuration conf) throws IOException {
        synchronized (refreshNamenodesLock) {
            //      List<InetSocketAddress> namenodes = DFSUtil.getNameNodesRPCAddresses(conf);
            List<InetSocketAddress> namenodes = DFSUtil.getNameNodesServiceRpcAddresses(conf);
            offerServices.add(createBPOS(namenodes));
            startAll();
        }
    }

    /**
     * Extracted out for test purposes.
     */
    protected BPOfferService createBPOS(List<InetSocketAddress> nnAddrs) {
        return new BPOfferService(nnAddrs, dn);
    }
}