bookkeeper-server/src/main/java/org/apache/bookkeeper/client/ZoneawareEnsemblePlacementPolicy.java

/**
 * 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.bookkeeper.client;

import io.netty.util.HashedWheelTimer;

import java.util.List;
import java.util.Map;
import java.util.Optional;
import java.util.Set;

import org.apache.bookkeeper.conf.ClientConfiguration;
import org.apache.bookkeeper.feature.FeatureProvider;
import org.apache.bookkeeper.net.BookieNode;
import org.apache.bookkeeper.net.BookieSocketAddress;
import org.apache.bookkeeper.net.DNSToSwitchMapping;
import org.apache.bookkeeper.stats.StatsLogger;

/**
 * A placement policy implementation use zone information for placing ensembles.
 *
 * @see EnsemblePlacementPolicy
 */
public class ZoneawareEnsemblePlacementPolicy extends ZoneawareEnsemblePlacementPolicyImpl
        implements ITopologyAwareEnsemblePlacementPolicy<BookieNode> {
    ZoneawareEnsemblePlacementPolicyImpl slave = null;

    public ZoneawareEnsemblePlacementPolicy() {
        super();
    }

    @Override
    public EnsemblePlacementPolicy initialize(ClientConfiguration conf,
            Optional<DNSToSwitchMapping> optionalDnsResolver, HashedWheelTimer timer, FeatureProvider featureProvider,
            StatsLogger statsLogger) {
        if (conf.getNetworkTopologyStabilizePeriodSeconds() > 0) {
            ClientConfiguration confClone = new ClientConfiguration(conf);
            confClone.setNetworkTopologyStabilizePeriodSeconds(0);
            super.initialize(confClone, optionalDnsResolver, timer, featureProvider, statsLogger);
            slave = new ZoneawareEnsemblePlacementPolicyImpl();
            slave.initialize(conf, optionalDnsResolver, timer, featureProvider, statsLogger);
        } else {
            super.initialize(conf, optionalDnsResolver, timer, featureProvider, statsLogger);
            slave = null;
        }
        return this;
    }

    @Override
    public void uninitalize() {
        super.uninitalize();
        if (null != slave) {
            slave.uninitalize();
        }
    }

    @Override
    public Set<BookieSocketAddress> onClusterChanged(Set<BookieSocketAddress> writableBookies,
            Set<BookieSocketAddress> readOnlyBookies) {
        Set<BookieSocketAddress> deadBookies = super.onClusterChanged(writableBookies, readOnlyBookies);
        if (null != slave) {
            deadBookies = slave.onClusterChanged(writableBookies, readOnlyBookies);
        }
        return deadBookies;
    }

    @Override
    public PlacementResult<List<BookieSocketAddress>> newEnsemble(int ensembleSize, int writeQuorumSize,
            int ackQuorumSize, Map<String, byte[]> customMetadata, Set<BookieSocketAddress> excludeBookies)
            throws BKException.BKNotEnoughBookiesException {
        try {
            return super.newEnsemble(ensembleSize, writeQuorumSize, ackQuorumSize, customMetadata, excludeBookies);
        } catch (BKException.BKNotEnoughBookiesException bnebe) {
            if (slave == null) {
                throw bnebe;
            } else {
                return slave.newEnsemble(ensembleSize, writeQuorumSize, ackQuorumSize, customMetadata, excludeBookies);
            }
        }
    }

    @Override
    public PlacementResult<BookieSocketAddress> replaceBookie(int ensembleSize, int writeQuorumSize, int ackQuorumSize,
            Map<String, byte[]> customMetadata, List<BookieSocketAddress> currentEnsemble,
            BookieSocketAddress bookieToReplace, Set<BookieSocketAddress> excludeBookies)
            throws BKException.BKNotEnoughBookiesException {
       try {
            return super.replaceBookie(ensembleSize, writeQuorumSize, ackQuorumSize, customMetadata,
                    currentEnsemble, bookieToReplace, excludeBookies);
        } catch (BKException.BKNotEnoughBookiesException bnebe) {
            if (slave == null) {
                throw bnebe;
            } else {
                return slave.replaceBookie(ensembleSize, writeQuorumSize, ackQuorumSize, customMetadata,
                        currentEnsemble, bookieToReplace, excludeBookies);
            }
        }
    }

    @Override
    public void handleBookiesThatLeft(Set<BookieSocketAddress> leftBookies) {
        super.handleBookiesThatLeft(leftBookies);
        if (null != slave) {
            slave.handleBookiesThatLeft(leftBookies);
        }
    }

    @Override
    public void handleBookiesThatJoined(Set<BookieSocketAddress> joinedBookies) {
        super.handleBookiesThatJoined(joinedBookies);
        if (null != slave) {
            slave.handleBookiesThatJoined(joinedBookies);
        }
    }
}