ReduceTaskRunner.java
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上传日期:2018-01-08
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文件大小:2k
- /**
- * Licensed to the Apache Software Foundation (ASF) under one
- * or more contributor license agreements. See the NOTICE file
- * distributed with this work for additional information
- * regarding copyright ownership. The ASF licenses this file
- * to you under the Apache License, Version 2.0 (the
- * "License"); you may not use this file except in compliance
- * with the License. You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
- package org.apache.hadoop.mapred;
- import java.io.*;
- import org.apache.hadoop.mapred.TaskTracker.TaskInProgress;
- /** Runs a reduce task. */
- class ReduceTaskRunner extends TaskRunner {
-
- public ReduceTaskRunner(TaskInProgress task, TaskTracker tracker,
- JobConf conf) throws IOException {
-
- super(task, tracker, conf);
- }
- /** Assemble all of the map output files */
- public boolean prepare() throws IOException {
- if (!super.prepare()) {
- return false;
- }
-
- // cleanup from failures
- mapOutputFile.removeAll(getTask().getTaskID());
- return true;
- }
-
-
- /** Delete all of the temporary map output files. */
- public void close() throws IOException {
- LOG.info(getTask()+" done; removing files.");
- getTask().getProgress().setStatus("closed");
- mapOutputFile.removeAll(getTask().getTaskID());
- }
- }