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
019package org.apache.hadoop.mapred;
020
021import java.io.DataInput;
022import java.io.IOException;
023
024import org.apache.hadoop.classification.InterfaceAudience;
025import org.apache.hadoop.classification.InterfaceStability;
026import org.apache.hadoop.mapreduce.TaskType;
027
028/**
029 * TaskAttemptID represents the immutable and unique identifier for 
030 * a task attempt. Each task attempt is one particular instance of a Map or
031 * Reduce Task identified by its TaskID. 
032 * 
033 * TaskAttemptID consists of 2 parts. First part is the 
034 * {@link TaskID}, that this TaskAttemptID belongs to.
035 * Second part is the task attempt number. <br> 
036 * An example TaskAttemptID is : 
037 * <code>attempt_200707121733_0003_m_000005_0</code> , which represents the
038 * zeroth task attempt for the fifth map task in the third job 
039 * running at the jobtracker started at <code>200707121733</code>.
040 * <p>
041 * Applications should never construct or parse TaskAttemptID strings
042 * , but rather use appropriate constructors or {@link #forName(String)} 
043 * method. 
044 * 
045 * @see JobID
046 * @see TaskID
047 */
048@InterfaceAudience.Public
049@InterfaceStability.Stable
050public class TaskAttemptID extends org.apache.hadoop.mapreduce.TaskAttemptID {
051  
052  /**
053   * Constructs a TaskAttemptID object from given {@link TaskID}.  
054   * @param taskId TaskID that this task belongs to  
055   * @param id the task attempt number
056   */
057  public TaskAttemptID(TaskID taskId, int id) {
058    super(taskId, id);
059  }
060  
061  /**
062   * Constructs a TaskId object from given parts.
063   * @param jtIdentifier jobTracker identifier
064   * @param jobId job number 
065   * @param isMap whether the tip is a map 
066   * @param taskId taskId number
067   * @param id the task attempt number
068   * @deprecated Use {@link #TaskAttemptID(String, int, TaskType, int, int)}.
069   */
070  @Deprecated
071  public TaskAttemptID(String jtIdentifier, int jobId, boolean isMap, 
072      int taskId, int id) {
073    this(jtIdentifier, jobId, isMap ? TaskType.MAP : TaskType.REDUCE, taskId,
074        id);
075  }
076  
077  /**
078   * Constructs a TaskId object from given parts.
079   * @param jtIdentifier jobTracker identifier
080   * @param jobId job number 
081   * @param type the TaskType 
082   * @param taskId taskId number
083   * @param id the task attempt number
084   */
085  public TaskAttemptID(String jtIdentifier, int jobId, TaskType type, 
086                       int taskId, int id) {
087    this(new TaskID(jtIdentifier, jobId, type, taskId), id);
088  }
089  
090  public TaskAttemptID() { 
091    super(new TaskID(), 0);
092  }
093
094  /**
095   * Downgrade a new TaskAttemptID to an old one
096   * @param old the new id
097   * @return either old or a new TaskAttemptID constructed to match old
098   */
099  public static 
100  TaskAttemptID downgrade(org.apache.hadoop.mapreduce.TaskAttemptID old) {
101    if (old instanceof TaskAttemptID) {
102      return (TaskAttemptID) old;
103    } else {
104      return new TaskAttemptID(TaskID.downgrade(old.getTaskID()), old.getId());
105    }
106  }
107
108  public TaskID getTaskID() {
109    return (TaskID) super.getTaskID();
110  }
111
112  public JobID getJobID() {
113    return (JobID) super.getJobID();
114  }
115
116  @Deprecated
117  public static TaskAttemptID read(DataInput in) throws IOException {
118    TaskAttemptID taskId = new TaskAttemptID();
119    taskId.readFields(in);
120    return taskId;
121  }
122  
123  /** Construct a TaskAttemptID object from given string 
124   * @return constructed TaskAttemptID object or null if the given String is null
125   * @throws IllegalArgumentException if the given string is malformed
126   */
127  public static TaskAttemptID forName(String str
128                                      ) throws IllegalArgumentException {
129    return (TaskAttemptID) 
130             org.apache.hadoop.mapreduce.TaskAttemptID.forName(str);
131  }
132  
133  /** 
134   * Returns a regex pattern which matches task attempt IDs. Arguments can 
135   * be given null, in which case that part of the regex will be generic.  
136   * For example to obtain a regex matching <i>all task attempt IDs</i> 
137   * of <i>any jobtracker</i>, in <i>any job</i>, of the <i>first 
138   * map task</i>, we would use :
139   * <pre> 
140   * TaskAttemptID.getTaskAttemptIDsPattern(null, null, true, 1, null);
141   * </pre>
142   * which will return :
143   * <pre> "attempt_[^_]*_[0-9]*_m_000001_[0-9]*" </pre> 
144   * @param jtIdentifier jobTracker identifier, or null
145   * @param jobId job number, or null
146   * @param isMap whether the tip is a map, or null 
147   * @param taskId taskId number, or null
148   * @param attemptId the task attempt number, or null
149   * @return a regex pattern matching TaskAttemptIDs
150   */
151  @Deprecated
152  public static String getTaskAttemptIDsPattern(String jtIdentifier,
153      Integer jobId, Boolean isMap, Integer taskId, Integer attemptId) {
154    return getTaskAttemptIDsPattern(jtIdentifier, jobId,
155        isMap ? TaskType.MAP : TaskType.REDUCE, taskId, attemptId);
156  }
157  
158  /** 
159   * Returns a regex pattern which matches task attempt IDs. Arguments can 
160   * be given null, in which case that part of the regex will be generic.  
161   * For example to obtain a regex matching <i>all task attempt IDs</i> 
162   * of <i>any jobtracker</i>, in <i>any job</i>, of the <i>first 
163   * map task</i>, we would use :
164   * <pre> 
165   * TaskAttemptID.getTaskAttemptIDsPattern(null, null, TaskType.MAP, 1, null);
166   * </pre>
167   * which will return :
168   * <pre> "attempt_[^_]*_[0-9]*_m_000001_[0-9]*" </pre> 
169   * @param jtIdentifier jobTracker identifier, or null
170   * @param jobId job number, or null
171   * @param type the {@link TaskType} 
172   * @param taskId taskId number, or null
173   * @param attemptId the task attempt number, or null
174   * @return a regex pattern matching TaskAttemptIDs
175   */
176  @Deprecated
177  public static String getTaskAttemptIDsPattern(String jtIdentifier,
178      Integer jobId, TaskType type, Integer taskId, Integer attemptId) {
179    StringBuilder builder = new StringBuilder(ATTEMPT).append(SEPARATOR);
180    builder.append(getTaskAttemptIDsPatternWOPrefix(jtIdentifier, jobId,
181        type, taskId, attemptId));
182    return builder.toString();
183  }
184  
185  @Deprecated
186  static StringBuilder getTaskAttemptIDsPatternWOPrefix(String jtIdentifier
187      , Integer jobId, TaskType type, Integer taskId, Integer attemptId) {
188    StringBuilder builder = new StringBuilder();
189    builder.append(TaskID.getTaskIDsPatternWOPrefix(jtIdentifier
190        , jobId, type, taskId))
191        .append(SEPARATOR)
192        .append(attemptId != null ? attemptId : "[0-9]*");
193    return builder;
194  }
195}