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.balancer;
019
020import java.io.IOException;
021import org.apache.hadoop.hbase.HConstants;
022import org.apache.hadoop.hbase.ScheduledChore;
023import org.apache.hadoop.hbase.master.HMaster;
024import org.apache.yetus.audience.InterfaceAudience;
025import org.slf4j.Logger;
026import org.slf4j.LoggerFactory;
027
028/**
029 * Chore that will call HMaster.balance{@link org.apache.hadoop.hbase.master.HMaster#balance()} when
030 * needed.
031 */
032@InterfaceAudience.Private
033public class BalancerChore extends ScheduledChore {
034  private static final Logger LOG = LoggerFactory.getLogger(BalancerChore.class);
035
036  private final HMaster master;
037
038  public BalancerChore(HMaster master) {
039    super(master.getServerName() + "-BalancerChore", master, master.getConfiguration()
040      .getInt(HConstants.HBASE_BALANCER_PERIOD, HConstants.DEFAULT_HBASE_BALANCER_PERIOD));
041    this.master = master;
042  }
043
044  @Override
045  protected void chore() {
046    try {
047      master.balanceOrUpdateMetrics();
048    } catch (IOException e) {
049      LOG.error("Failed to balance.", e);
050    }
051  }
052}