1 | /** |
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2 | * Licensed to the Apache Software Foundation (ASF) under one |
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3 | * or more contributor license agreements. See the NOTICE file |
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4 | * distributed with this work for additional information |
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5 | * regarding copyright ownership. The ASF licenses this file |
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6 | * to you under the Apache License, Version 2.0 (the |
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7 | * "License"); you may not use this file except in compliance |
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8 | * with the License. You may obtain a copy of the License at |
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9 | * |
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10 | * http://www.apache.org/licenses/LICENSE-2.0 |
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11 | * |
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12 | * Unless required by applicable law or agreed to in writing, software |
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13 | * distributed under the License is distributed on an "AS IS" BASIS, |
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14 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
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15 | * See the License for the specific language governing permissions and |
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16 | * limitations under the License. |
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17 | */ |
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18 | |
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19 | package org.apache.hadoop.mapreduce; |
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20 | |
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21 | import java.io.IOException; |
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22 | |
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23 | import org.apache.hadoop.conf.Configuration; |
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24 | import org.apache.hadoop.fs.Path; |
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25 | import org.apache.hadoop.io.RawComparator; |
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26 | import org.apache.hadoop.mapreduce.TaskAttemptID; |
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27 | import org.apache.hadoop.mapred.JobClient; |
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28 | import org.apache.hadoop.mapred.JobConf; |
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29 | import org.apache.hadoop.mapred.RunningJob; |
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30 | import org.apache.hadoop.mapred.TaskCompletionEvent; |
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31 | |
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32 | /** |
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33 | * The job submitter's view of the Job. It allows the user to configure the |
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34 | * job, submit it, control its execution, and query the state. The set methods |
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35 | * only work until the job is submitted, afterwards they will throw an |
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36 | * IllegalStateException. |
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37 | */ |
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38 | public class Job extends JobContext { |
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39 | public static enum JobState {DEFINE, RUNNING}; |
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40 | private JobState state = JobState.DEFINE; |
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41 | private JobClient jobClient; |
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42 | private RunningJob info; |
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43 | |
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44 | public Job() throws IOException { |
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45 | this(new Configuration()); |
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46 | } |
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47 | |
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48 | public Job(Configuration conf) throws IOException { |
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49 | super(conf, null); |
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50 | jobClient = new JobClient((JobConf) getConfiguration()); |
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51 | } |
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52 | |
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53 | public Job(Configuration conf, String jobName) throws IOException { |
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54 | this(conf); |
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55 | setJobName(jobName); |
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56 | } |
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57 | |
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58 | private void ensureState(JobState state) throws IllegalStateException { |
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59 | if (state != this.state) { |
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60 | throw new IllegalStateException("Job in state "+ this.state + |
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61 | " instead of " + state); |
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62 | } |
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63 | } |
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64 | |
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65 | /** |
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66 | * Set the number of reduce tasks for the job. |
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67 | * @param tasks the number of reduce tasks |
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68 | * @throws IllegalStateException if the job is submitted |
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69 | */ |
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70 | public void setNumReduceTasks(int tasks) throws IllegalStateException { |
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71 | ensureState(JobState.DEFINE); |
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72 | conf.setNumReduceTasks(tasks); |
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73 | } |
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74 | |
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75 | /** |
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76 | * Set the current working directory for the default file system. |
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77 | * |
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78 | * @param dir the new current working directory. |
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79 | * @throws IllegalStateException if the job is submitted |
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80 | */ |
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81 | public void setWorkingDirectory(Path dir) throws IOException { |
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82 | ensureState(JobState.DEFINE); |
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83 | conf.setWorkingDirectory(dir); |
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84 | } |
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85 | |
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86 | /** |
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87 | * Set the {@link InputFormat} for the job. |
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88 | * @param cls the <code>InputFormat</code> to use |
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89 | * @throws IllegalStateException if the job is submitted |
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90 | */ |
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91 | public void setInputFormatClass(Class<? extends InputFormat> cls |
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92 | ) throws IllegalStateException { |
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93 | ensureState(JobState.DEFINE); |
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94 | conf.setClass(INPUT_FORMAT_CLASS_ATTR, cls, InputFormat.class); |
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95 | } |
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96 | |
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97 | /** |
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98 | * Set the {@link OutputFormat} for the job. |
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99 | * @param cls the <code>OutputFormat</code> to use |
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100 | * @throws IllegalStateException if the job is submitted |
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101 | */ |
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102 | public void setOutputFormatClass(Class<? extends OutputFormat> cls |
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103 | ) throws IllegalStateException { |
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104 | ensureState(JobState.DEFINE); |
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105 | conf.setClass(OUTPUT_FORMAT_CLASS_ATTR, cls, OutputFormat.class); |
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106 | } |
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107 | |
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108 | /** |
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109 | * Set the {@link Mapper} for the job. |
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110 | * @param cls the <code>Mapper</code> to use |
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111 | * @throws IllegalStateException if the job is submitted |
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112 | */ |
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113 | public void setMapperClass(Class<? extends Mapper> cls |
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114 | ) throws IllegalStateException { |
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115 | ensureState(JobState.DEFINE); |
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116 | conf.setClass(MAP_CLASS_ATTR, cls, Mapper.class); |
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117 | } |
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118 | |
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119 | /** |
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120 | * Set the Jar by finding where a given class came from. |
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121 | * @param cls the example class |
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122 | */ |
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123 | public void setJarByClass(Class<?> cls) { |
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124 | conf.setJarByClass(cls); |
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125 | } |
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126 | |
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127 | /** |
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128 | * Get the pathname of the job's jar. |
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129 | * @return the pathname |
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130 | */ |
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131 | public String getJar() { |
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132 | return conf.getJar(); |
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133 | } |
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134 | |
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135 | /** |
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136 | * Set the combiner class for the job. |
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137 | * @param cls the combiner to use |
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138 | * @throws IllegalStateException if the job is submitted |
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139 | */ |
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140 | public void setCombinerClass(Class<? extends Reducer> cls |
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141 | ) throws IllegalStateException { |
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142 | ensureState(JobState.DEFINE); |
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143 | conf.setClass(COMBINE_CLASS_ATTR, cls, Reducer.class); |
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144 | } |
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145 | |
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146 | /** |
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147 | * Set the {@link Reducer} for the job. |
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148 | * @param cls the <code>Reducer</code> to use |
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149 | * @throws IllegalStateException if the job is submitted |
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150 | */ |
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151 | public void setReducerClass(Class<? extends Reducer> cls |
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152 | ) throws IllegalStateException { |
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153 | ensureState(JobState.DEFINE); |
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154 | conf.setClass(REDUCE_CLASS_ATTR, cls, Reducer.class); |
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155 | } |
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156 | |
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157 | /** |
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158 | * Set the {@link Partitioner} for the job. |
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159 | * @param cls the <code>Partitioner</code> to use |
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160 | * @throws IllegalStateException if the job is submitted |
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161 | */ |
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162 | public void setPartitionerClass(Class<? extends Partitioner> cls |
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163 | ) throws IllegalStateException { |
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164 | ensureState(JobState.DEFINE); |
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165 | conf.setClass(PARTITIONER_CLASS_ATTR, cls, Partitioner.class); |
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166 | } |
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167 | |
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168 | /** |
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169 | * Set the key class for the map output data. This allows the user to |
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170 | * specify the map output key class to be different than the final output |
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171 | * value class. |
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172 | * |
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173 | * @param theClass the map output key class. |
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174 | * @throws IllegalStateException if the job is submitted |
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175 | */ |
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176 | public void setMapOutputKeyClass(Class<?> theClass |
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177 | ) throws IllegalStateException { |
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178 | ensureState(JobState.DEFINE); |
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179 | conf.setMapOutputKeyClass(theClass); |
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180 | } |
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181 | |
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182 | /** |
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183 | * Set the value class for the map output data. This allows the user to |
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184 | * specify the map output value class to be different than the final output |
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185 | * value class. |
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186 | * |
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187 | * @param theClass the map output value class. |
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188 | * @throws IllegalStateException if the job is submitted |
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189 | */ |
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190 | public void setMapOutputValueClass(Class<?> theClass |
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191 | ) throws IllegalStateException { |
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192 | ensureState(JobState.DEFINE); |
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193 | conf.setMapOutputValueClass(theClass); |
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194 | } |
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195 | |
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196 | /** |
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197 | * Set the key class for the job output data. |
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198 | * |
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199 | * @param theClass the key class for the job output data. |
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200 | * @throws IllegalStateException if the job is submitted |
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201 | */ |
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202 | public void setOutputKeyClass(Class<?> theClass |
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203 | ) throws IllegalStateException { |
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204 | ensureState(JobState.DEFINE); |
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205 | conf.setOutputKeyClass(theClass); |
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206 | } |
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207 | |
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208 | /** |
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209 | * Set the value class for job outputs. |
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210 | * |
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211 | * @param theClass the value class for job outputs. |
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212 | * @throws IllegalStateException if the job is submitted |
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213 | */ |
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214 | public void setOutputValueClass(Class<?> theClass |
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215 | ) throws IllegalStateException { |
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216 | ensureState(JobState.DEFINE); |
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217 | conf.setOutputValueClass(theClass); |
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218 | } |
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219 | |
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220 | /** |
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221 | * Define the comparator that controls how the keys are sorted before they |
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222 | * are passed to the {@link Reducer}. |
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223 | * @param cls the raw comparator |
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224 | * @throws IllegalStateException if the job is submitted |
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225 | */ |
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226 | public void setSortComparatorClass(Class<? extends RawComparator> cls |
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227 | ) throws IllegalStateException { |
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228 | ensureState(JobState.DEFINE); |
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229 | conf.setOutputKeyComparatorClass(cls); |
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230 | } |
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231 | |
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232 | /** |
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233 | * Define the comparator that controls which keys are grouped together |
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234 | * for a single call to |
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235 | * {@link Reducer#reduce(Object, Iterable, |
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236 | * org.apache.hadoop.mapreduce.Reducer.Context)} |
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237 | * @param cls the raw comparator to use |
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238 | * @throws IllegalStateException if the job is submitted |
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239 | */ |
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240 | public void setGroupingComparatorClass(Class<? extends RawComparator> cls |
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241 | ) throws IllegalStateException { |
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242 | ensureState(JobState.DEFINE); |
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243 | conf.setOutputValueGroupingComparator(cls); |
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244 | } |
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245 | |
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246 | /** |
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247 | * Set the user-specified job name. |
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248 | * |
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249 | * @param name the job's new name. |
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250 | * @throws IllegalStateException if the job is submitted |
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251 | */ |
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252 | public void setJobName(String name) throws IllegalStateException { |
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253 | ensureState(JobState.DEFINE); |
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254 | conf.setJobName(name); |
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255 | } |
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256 | |
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257 | /** |
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258 | * Get the URL where some job progress information will be displayed. |
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259 | * |
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260 | * @return the URL where some job progress information will be displayed. |
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261 | */ |
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262 | public String getTrackingURL() { |
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263 | ensureState(JobState.RUNNING); |
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264 | return info.getTrackingURL(); |
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265 | } |
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266 | |
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267 | /** |
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268 | * Get the <i>progress</i> of the job's map-tasks, as a float between 0.0 |
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269 | * and 1.0. When all map tasks have completed, the function returns 1.0. |
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270 | * |
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271 | * @return the progress of the job's map-tasks. |
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272 | * @throws IOException |
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273 | */ |
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274 | public float mapProgress() throws IOException { |
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275 | ensureState(JobState.RUNNING); |
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276 | return info.mapProgress(); |
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277 | } |
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278 | |
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279 | /** |
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280 | * Get the <i>progress</i> of the job's reduce-tasks, as a float between 0.0 |
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281 | * and 1.0. When all reduce tasks have completed, the function returns 1.0. |
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282 | * |
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283 | * @return the progress of the job's reduce-tasks. |
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284 | * @throws IOException |
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285 | */ |
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286 | public float reduceProgress() throws IOException { |
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287 | ensureState(JobState.RUNNING); |
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288 | return info.reduceProgress(); |
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289 | } |
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290 | |
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291 | /** |
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292 | * Check if the job is finished or not. |
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293 | * This is a non-blocking call. |
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294 | * |
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295 | * @return <code>true</code> if the job is complete, else <code>false</code>. |
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296 | * @throws IOException |
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297 | */ |
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298 | public boolean isComplete() throws IOException { |
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299 | ensureState(JobState.RUNNING); |
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300 | return info.isComplete(); |
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301 | } |
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302 | |
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303 | /** |
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304 | * Check if the job completed successfully. |
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305 | * |
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306 | * @return <code>true</code> if the job succeeded, else <code>false</code>. |
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307 | * @throws IOException |
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308 | */ |
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309 | public boolean isSuccessful() throws IOException { |
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310 | ensureState(JobState.RUNNING); |
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311 | return info.isSuccessful(); |
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312 | } |
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313 | |
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314 | /** |
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315 | * Kill the running job. Blocks until all job tasks have been |
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316 | * killed as well. If the job is no longer running, it simply returns. |
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317 | * |
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318 | * @throws IOException |
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319 | */ |
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320 | public void killJob() throws IOException { |
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321 | ensureState(JobState.RUNNING); |
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322 | info.killJob(); |
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323 | } |
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324 | |
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325 | /** |
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326 | * Get events indicating completion (success/failure) of component tasks. |
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327 | * |
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328 | * @param startFrom index to start fetching events from |
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329 | * @return an array of {@link TaskCompletionEvent}s |
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330 | * @throws IOException |
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331 | */ |
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332 | public TaskCompletionEvent[] getTaskCompletionEvents(int startFrom |
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333 | ) throws IOException { |
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334 | ensureState(JobState.RUNNING); |
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335 | return info.getTaskCompletionEvents(startFrom); |
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336 | } |
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337 | |
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338 | /** |
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339 | * Kill indicated task attempt. |
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340 | * |
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341 | * @param taskId the id of the task to be terminated. |
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342 | * @throws IOException |
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343 | */ |
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344 | public void killTask(TaskAttemptID taskId) throws IOException { |
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345 | ensureState(JobState.RUNNING); |
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346 | info.killTask(org.apache.hadoop.mapred.TaskAttemptID.downgrade(taskId), |
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347 | false); |
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348 | } |
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349 | |
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350 | /** |
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351 | * Fail indicated task attempt. |
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352 | * |
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353 | * @param taskId the id of the task to be terminated. |
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354 | * @throws IOException |
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355 | */ |
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356 | public void failTask(TaskAttemptID taskId) throws IOException { |
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357 | ensureState(JobState.RUNNING); |
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358 | info.killTask(org.apache.hadoop.mapred.TaskAttemptID.downgrade(taskId), |
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359 | true); |
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360 | } |
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361 | |
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362 | /** |
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363 | * Gets the counters for this job. |
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364 | * |
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365 | * @return the counters for this job. |
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366 | * @throws IOException |
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367 | */ |
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368 | public Counters getCounters() throws IOException { |
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369 | ensureState(JobState.RUNNING); |
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370 | return new Counters(info.getCounters()); |
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371 | } |
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372 | |
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373 | private void ensureNotSet(String attr, String msg) throws IOException { |
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374 | if (conf.get(attr) != null) { |
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375 | throw new IOException(attr + " is incompatible with " + msg + " mode."); |
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376 | } |
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377 | } |
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378 | |
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379 | /** |
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380 | * Default to the new APIs unless they are explicitly set or the old mapper or |
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381 | * reduce attributes are used. |
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382 | * @throws IOException if the configuration is inconsistant |
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383 | */ |
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384 | private void setUseNewAPI() throws IOException { |
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385 | int numReduces = conf.getNumReduceTasks(); |
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386 | String oldMapperClass = "mapred.mapper.class"; |
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387 | String oldReduceClass = "mapred.reducer.class"; |
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388 | conf.setBooleanIfUnset("mapred.mapper.new-api", |
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389 | conf.get(oldMapperClass) == null); |
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390 | if (conf.getUseNewMapper()) { |
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391 | String mode = "new map API"; |
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392 | ensureNotSet("mapred.input.format.class", mode); |
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393 | ensureNotSet(oldMapperClass, mode); |
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394 | if (numReduces != 0) { |
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395 | ensureNotSet("mapred.partitioner.class", mode); |
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396 | } else { |
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397 | ensureNotSet("mapred.output.format.class", mode); |
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398 | } |
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399 | } else { |
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400 | String mode = "map compatability"; |
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401 | ensureNotSet(JobContext.INPUT_FORMAT_CLASS_ATTR, mode); |
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402 | ensureNotSet(JobContext.MAP_CLASS_ATTR, mode); |
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403 | if (numReduces != 0) { |
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404 | ensureNotSet(JobContext.PARTITIONER_CLASS_ATTR, mode); |
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405 | } else { |
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406 | ensureNotSet(JobContext.OUTPUT_FORMAT_CLASS_ATTR, mode); |
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407 | } |
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408 | } |
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409 | if (numReduces != 0) { |
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410 | conf.setBooleanIfUnset("mapred.reducer.new-api", |
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411 | conf.get(oldReduceClass) == null); |
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412 | if (conf.getUseNewReducer()) { |
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413 | String mode = "new reduce API"; |
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414 | ensureNotSet("mapred.output.format.class", mode); |
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415 | ensureNotSet(oldReduceClass, mode); |
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416 | } else { |
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417 | String mode = "reduce compatability"; |
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418 | ensureNotSet(JobContext.OUTPUT_FORMAT_CLASS_ATTR, mode); |
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419 | ensureNotSet(JobContext.REDUCE_CLASS_ATTR, mode); |
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420 | } |
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421 | } |
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422 | } |
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423 | |
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424 | /** |
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425 | * Submit the job to the cluster and return immediately. |
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426 | * @throws IOException |
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427 | */ |
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428 | public void submit() throws IOException, InterruptedException, |
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429 | ClassNotFoundException { |
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430 | ensureState(JobState.DEFINE); |
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431 | setUseNewAPI(); |
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432 | info = jobClient.submitJobInternal(conf); |
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433 | state = JobState.RUNNING; |
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434 | } |
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435 | |
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436 | /** |
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437 | * Submit the job to the cluster and wait for it to finish. |
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438 | * @param verbose print the progress to the user |
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439 | * @return true if the job succeeded |
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440 | * @throws IOException thrown if the communication with the |
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441 | * <code>JobTracker</code> is lost |
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442 | */ |
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443 | public boolean waitForCompletion(boolean verbose |
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444 | ) throws IOException, InterruptedException, |
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445 | ClassNotFoundException { |
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446 | if (state == JobState.DEFINE) { |
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447 | submit(); |
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448 | } |
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449 | if (verbose) { |
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450 | jobClient.monitorAndPrintJob(conf, info); |
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451 | } else { |
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452 | info.waitForCompletion(); |
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453 | } |
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454 | return isSuccessful(); |
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455 | } |
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456 | |
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457 | } |
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