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 }