1 /** 2 * Licensed to the Apache Software Foundation (ASF) under one 3 * or more contributor license agreements. See the NOTICE file 4 * distributed with this work for additional information 5 * regarding copyright ownership. The ASF licenses this file 6 * to you under the Apache License, Version 2.0 (the 7 * "License"); you may not use this file except in compliance 8 * with the License. You may obtain a copy of the License at 9 * 10 * http://www.apache.org/licenses/LICENSE-2.0 11 * 12 * Unless required by applicable law or agreed to in writing, software 13 * distributed under the License is distributed on an "AS IS" BASIS, 14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 15 * See the License for the specific language governing permissions and 16 * limitations under the License. 17 */ 18 package org.apache.hadoop.hbase.master.balancer; 19 20 import java.util.Comparator; 21 22 import org.apache.hadoop.hbase.HRegionInfo; 23 24 /** 25 * The following comparator assumes that RegionId from HRegionInfo can represent 26 * the age of the region - larger RegionId means the region is younger. This 27 * comparator is used in balanceCluster() to account for the out-of-band regions 28 * which were assigned to the server after some other region server crashed. 29 */ 30 class RegionInfoComparator implements Comparator<HRegionInfo> { 31 @Override 32 public int compare(HRegionInfo l, HRegionInfo r) { 33 long diff = r.getRegionId() - l.getRegionId(); 34 if (diff < 0) return -1; 35 if (diff > 0) return 1; 36 return 0; 37 } 38 }