001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.hadoop.hbase.master.zksyncer;
019
020import java.util.Set;
021import java.util.stream.Collectors;
022import java.util.stream.IntStream;
023import org.apache.hadoop.hbase.Server;
024import org.apache.hadoop.hbase.zookeeper.ZKWatcher;
025import org.apache.yetus.audience.InterfaceAudience;
026
027/**
028 * Tracks the meta region locations on server ZK cluster and synchronize them to client ZK cluster
029 * if changed
030 */
031@InterfaceAudience.Private
032public class MetaLocationSyncer extends ClientZKSyncer {
033
034  private volatile int metaReplicaCount = 1;
035
036  public MetaLocationSyncer(ZKWatcher watcher, ZKWatcher clientZkWatcher, Server server) {
037    super(watcher, clientZkWatcher, server);
038  }
039
040  @Override
041  protected boolean validate(String path) {
042    return watcher.getZNodePaths().isMetaZNodePath(path);
043  }
044
045  @Override
046  protected Set<String> getPathsToWatch() {
047    return IntStream.range(0, metaReplicaCount)
048      .mapToObj(watcher.getZNodePaths()::getZNodeForReplica).collect(Collectors.toSet());
049  }
050
051  public void setMetaReplicaCount(int replicaCount) {
052    if (replicaCount != metaReplicaCount) {
053      metaReplicaCount = replicaCount;
054      refreshWatchingList();
055    }
056  }
057}