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.mapreduce.task.reduce; 19 20 import java.util.ArrayList; 21 import java.util.List; 22 23 import org.apache.hadoop.classification.InterfaceAudience; 24 import org.apache.hadoop.classification.InterfaceStability; 25 26 import org.apache.hadoop.mapreduce.TaskAttemptID; 27 28 @InterfaceAudience.LimitedPrivate({"MapReduce"}) 29 @InterfaceStability.Unstable 30 public class MapHost { 31 32 public static enum State { 33 IDLE, // No map outputs available 34 BUSY, // Map outputs are being fetched 35 PENDING, // Known map outputs which need to be fetched 36 PENALIZED // Host penalized due to shuffle failures 37 } 38 39 private State state = State.IDLE; 40 private final String hostName; 41 private final String baseUrl; 42 private List<TaskAttemptID> maps = new ArrayList<TaskAttemptID>(); 43 MapHost(String hostName, String baseUrl)44 public MapHost(String hostName, String baseUrl) { 45 this.hostName = hostName; 46 this.baseUrl = baseUrl; 47 } 48 getState()49 public State getState() { 50 return state; 51 } 52 getHostName()53 public String getHostName() { 54 return hostName; 55 } 56 getBaseUrl()57 public String getBaseUrl() { 58 return baseUrl; 59 } 60 addKnownMap(TaskAttemptID mapId)61 public synchronized void addKnownMap(TaskAttemptID mapId) { 62 maps.add(mapId); 63 if (state == State.IDLE) { 64 state = State.PENDING; 65 } 66 } 67 getAndClearKnownMaps()68 public synchronized List<TaskAttemptID> getAndClearKnownMaps() { 69 List<TaskAttemptID> currentKnownMaps = maps; 70 maps = new ArrayList<TaskAttemptID>(); 71 return currentKnownMaps; 72 } 73 markBusy()74 public synchronized void markBusy() { 75 state = State.BUSY; 76 } 77 markPenalized()78 public synchronized void markPenalized() { 79 state = State.PENALIZED; 80 } 81 getNumKnownMapOutputs()82 public synchronized int getNumKnownMapOutputs() { 83 return maps.size(); 84 } 85 86 /** 87 * Called when the node is done with its penalty or done copying. 88 * @return the host's new state 89 */ markAvailable()90 public synchronized State markAvailable() { 91 if (maps.isEmpty()) { 92 state = State.IDLE; 93 } else { 94 state = State.PENDING; 95 } 96 return state; 97 } 98 99 @Override toString()100 public String toString() { 101 return hostName; 102 } 103 104 /** 105 * Mark the host as penalized 106 */ penalize()107 public synchronized void penalize() { 108 state = State.PENALIZED; 109 } 110 } 111