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 */ 018 019 package org.apache.hadoop.mapred; 020 021 import java.io.DataInput; 022 import java.io.IOException; 023 024 import org.apache.hadoop.classification.InterfaceAudience; 025 import org.apache.hadoop.classification.InterfaceStability; 026 import org.apache.hadoop.mapreduce.TaskType; 027 028 /** 029 * TaskID represents the immutable and unique identifier for 030 * a Map or Reduce Task. Each TaskID encompasses multiple attempts made to 031 * execute the Map or Reduce Task, each of which are uniquely indentified by 032 * their TaskAttemptID. 033 * 034 * TaskID consists of 3 parts. First part is the {@link JobID}, that this 035 * TaskInProgress belongs to. Second part of the TaskID is either 'm' or 'r' 036 * representing whether the task is a map task or a reduce task. 037 * And the third part is the task number. <br> 038 * An example TaskID is : 039 * <code>task_200707121733_0003_m_000005</code> , which represents the 040 * fifth map task in the third job running at the jobtracker 041 * started at <code>200707121733</code>. 042 * <p> 043 * Applications should never construct or parse TaskID strings 044 * , but rather use appropriate constructors or {@link #forName(String)} 045 * method. 046 * 047 * @see JobID 048 * @see TaskAttemptID 049 */ 050 @InterfaceAudience.Public 051 @InterfaceStability.Stable 052 public class TaskID extends org.apache.hadoop.mapreduce.TaskID { 053 054 /** 055 * Constructs a TaskID object from given {@link JobID}. 056 * @param jobId JobID that this tip belongs to 057 * @param isMap whether the tip is a map 058 * @param id the tip number 059 * @deprecated Use {@link #TaskID(String, int, TaskType, int)} 060 */ 061 @Deprecated 062 public TaskID(org.apache.hadoop.mapreduce.JobID jobId, boolean isMap,int id) { 063 this(jobId, isMap ? TaskType.MAP : TaskType.REDUCE, id); 064 } 065 066 /** 067 * Constructs a TaskInProgressId object from given parts. 068 * @param jtIdentifier jobTracker identifier 069 * @param jobId job number 070 * @param isMap whether the tip is a map 071 * @param id the tip number 072 * @deprecated Use {@link #TaskID(org.apache.hadoop.mapreduce.JobID, TaskType, 073 * int)} 074 */ 075 @Deprecated 076 public TaskID(String jtIdentifier, int jobId, boolean isMap, int id) { 077 this(jtIdentifier, jobId, isMap ? TaskType.MAP : TaskType.REDUCE, id); 078 } 079 080 /** 081 * Constructs a TaskID object from given {@link JobID}. 082 * @param jobId JobID that this tip belongs to 083 * @param type the {@link TaskType} 084 * @param id the tip number 085 */ 086 public TaskID(org.apache.hadoop.mapreduce.JobID jobId, TaskType type,int id) { 087 super(jobId, type, id); 088 } 089 090 /** 091 * Constructs a TaskInProgressId object from given parts. 092 * @param jtIdentifier jobTracker identifier 093 * @param jobId job number 094 * @param type the {@link TaskType} 095 * @param id the tip number 096 */ 097 public TaskID(String jtIdentifier, int jobId, TaskType type, int id) { 098 this(new JobID(jtIdentifier, jobId), type, id); 099 } 100 101 public TaskID() { 102 super(new JobID(), TaskType.REDUCE, 0); 103 } 104 105 /** 106 * Downgrade a new TaskID to an old one 107 * @param old a new or old TaskID 108 * @return either old or a new TaskID build to match old 109 */ 110 public static TaskID downgrade(org.apache.hadoop.mapreduce.TaskID old) { 111 if (old instanceof TaskID) { 112 return (TaskID) old; 113 } else { 114 return new TaskID(JobID.downgrade(old.getJobID()), old.getTaskType(), 115 old.getId()); 116 } 117 } 118 119 @Deprecated 120 public static TaskID read(DataInput in) throws IOException { 121 TaskID tipId = new TaskID(); 122 tipId.readFields(in); 123 return tipId; 124 } 125 126 public JobID getJobID() { 127 return (JobID) super.getJobID(); 128 } 129 130 /** 131 * Returns a regex pattern which matches task IDs. Arguments can 132 * be given null, in which case that part of the regex will be generic. 133 * For example to obtain a regex matching <i>the first map task</i> 134 * of <i>any jobtracker</i>, of <i>any job</i>, we would use : 135 * <pre> 136 * TaskID.getTaskIDsPattern(null, null, true, 1); 137 * </pre> 138 * which will return : 139 * <pre> "task_[^_]*_[0-9]*_m_000001*" </pre> 140 * @param jtIdentifier jobTracker identifier, or null 141 * @param jobId job number, or null 142 * @param isMap whether the tip is a map, or null 143 * @param taskId taskId number, or null 144 * @return a regex pattern matching TaskIDs 145 * @deprecated Use {@link TaskID#getTaskIDsPattern(String, Integer, TaskType, 146 * Integer)} 147 */ 148 @Deprecated 149 public static String getTaskIDsPattern(String jtIdentifier, Integer jobId 150 , Boolean isMap, Integer taskId) { 151 return getTaskIDsPattern(jtIdentifier, jobId, 152 isMap ? TaskType.MAP : TaskType.REDUCE, taskId); 153 } 154 155 /** 156 * Returns a regex pattern which matches task IDs. Arguments can 157 * be given null, in which case that part of the regex will be generic. 158 * For example to obtain a regex matching <i>the first map task</i> 159 * of <i>any jobtracker</i>, of <i>any job</i>, we would use : 160 * <pre> 161 * TaskID.getTaskIDsPattern(null, null, true, 1); 162 * </pre> 163 * which will return : 164 * <pre> "task_[^_]*_[0-9]*_m_000001*" </pre> 165 * @param jtIdentifier jobTracker identifier, or null 166 * @param jobId job number, or null 167 * @param type the {@link TaskType}, or null 168 * @param taskId taskId number, or null 169 * @return a regex pattern matching TaskIDs 170 */ 171 @Deprecated 172 public static String getTaskIDsPattern(String jtIdentifier, Integer jobId 173 , TaskType type, Integer taskId) { 174 StringBuilder builder = new StringBuilder(TASK).append(SEPARATOR) 175 .append(getTaskIDsPatternWOPrefix(jtIdentifier, jobId, type, taskId)); 176 return builder.toString(); 177 } 178 179 @Deprecated 180 static StringBuilder getTaskIDsPatternWOPrefix(String jtIdentifier 181 , Integer jobId, TaskType type, Integer taskId) { 182 StringBuilder builder = new StringBuilder(); 183 builder.append(JobID.getJobIDsPatternWOPrefix(jtIdentifier, jobId)) 184 .append(SEPARATOR) 185 .append(type != null ? 186 (org.apache.hadoop.mapreduce.TaskID.getRepresentingCharacter(type)) : 187 org.apache.hadoop.mapreduce.TaskID.getAllTaskTypes()). 188 append(SEPARATOR) 189 .append(taskId != null ? idFormat.format(taskId) : "[0-9]*"); 190 return builder; 191 } 192 193 public static TaskID forName(String str 194 ) throws IllegalArgumentException { 195 return (TaskID) org.apache.hadoop.mapreduce.TaskID.forName(str); 196 } 197 198 }