| /** |
| * 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.yarn.server.resourcemanager.scheduler.fair; |
| |
| import java.io.Serializable; |
| import java.util.Comparator; |
| |
| import org.apache.hadoop.classification.InterfaceAudience.Private; |
| import org.apache.hadoop.classification.InterfaceStability.Unstable; |
| |
| /** |
| * Order {@link FSAppAttempt} objects by priority and then by submit time, as |
| * in the default scheduler in Hadoop. |
| */ |
| @Private |
| @Unstable |
| public class FifoAppComparator implements Comparator<FSAppAttempt>, Serializable { |
| private static final long serialVersionUID = 3428835083489547918L; |
| |
| public int compare(FSAppAttempt a1, FSAppAttempt a2) { |
| int res = a1.getPriority().compareTo(a2.getPriority()); |
| if (res == 0) { |
| if (a1.getStartTime() < a2.getStartTime()) { |
| res = -1; |
| } else { |
| res = (a1.getStartTime() == a2.getStartTime() ? 0 : 1); |
| } |
| } |
| if (res == 0) { |
| // If there is a tie, break it by app ID to get a deterministic order |
| res = a1.getApplicationId().compareTo(a2.getApplicationId()); |
| } |
| return res; |
| } |
| } |