| /** |
| * 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.Flushable; |
| import java.util.LinkedList; |
| import java.util.Queue; |
| |
| import org.apache.hadoop.classification.InterfaceStability; |
| import org.apache.log4j.FileAppender; |
| import org.apache.log4j.spi.LoggingEvent; |
| |
| /** |
| * A simple log4j-appender for the task child's |
| * map-reduce system logs. |
| * |
| */ |
| @InterfaceStability.Unstable |
| public class TaskLogAppender extends FileAppender implements Flushable { |
| private String taskId; //taskId should be managed as String rather than TaskID object |
| //so that log4j can configure it from the configuration(log4j.properties). |
| private Integer maxEvents; |
| private Queue<LoggingEvent> tail = null; |
| private Boolean isCleanup; |
| |
| // System properties passed in from JVM runner |
| static final String ISCLEANUP_PROPERTY = "hadoop.tasklog.iscleanup"; |
| static final String LOGSIZE_PROPERTY = "hadoop.tasklog.totalLogFileSize"; |
| static final String TASKID_PROPERTY = "hadoop.tasklog.taskid"; |
| |
| @Override |
| public void activateOptions() { |
| synchronized (this) { |
| setOptionsFromSystemProperties(); |
| |
| if (maxEvents > 0) { |
| tail = new LinkedList<LoggingEvent>(); |
| } |
| setFile(TaskLog.getTaskLogFile(TaskAttemptID.forName(taskId), |
| isCleanup, TaskLog.LogName.SYSLOG).toString()); |
| setAppend(true); |
| super.activateOptions(); |
| } |
| } |
| |
| /** |
| * The Task Runner passes in the options as system properties. Set |
| * the options if the setters haven't already been called. |
| */ |
| private synchronized void setOptionsFromSystemProperties() { |
| if (isCleanup == null) { |
| String propValue = System.getProperty(ISCLEANUP_PROPERTY, "false"); |
| isCleanup = Boolean.valueOf(propValue); |
| } |
| |
| if (taskId == null) { |
| taskId = System.getProperty(TASKID_PROPERTY); |
| } |
| |
| if (maxEvents == null) { |
| String propValue = System.getProperty(LOGSIZE_PROPERTY, "0"); |
| setTotalLogFileSize(Long.parseLong(propValue)); |
| } |
| } |
| |
| @Override |
| public void append(LoggingEvent event) { |
| synchronized (this) { |
| if (tail == null) { |
| super.append(event); |
| } else { |
| if (tail.size() >= maxEvents) { |
| tail.remove(); |
| } |
| tail.add(event); |
| } |
| } |
| } |
| |
| @Override |
| public void flush() { |
| if (qw != null) { |
| qw.flush(); |
| } |
| } |
| |
| @Override |
| public synchronized void close() { |
| if (tail != null) { |
| for(LoggingEvent event: tail) { |
| super.append(event); |
| } |
| } |
| super.close(); |
| } |
| |
| /** |
| * Getter/Setter methods for log4j. |
| */ |
| |
| public synchronized String getTaskId() { |
| return taskId; |
| } |
| |
| public synchronized void setTaskId(String taskId) { |
| this.taskId = taskId; |
| } |
| |
| private static final int EVENT_SIZE = 100; |
| |
| public synchronized long getTotalLogFileSize() { |
| return maxEvents * EVENT_SIZE; |
| } |
| |
| public synchronized void setTotalLogFileSize(long logSize) { |
| maxEvents = (int) logSize / EVENT_SIZE; |
| } |
| |
| /** |
| * Set whether the task is a cleanup attempt or not. |
| * |
| * @param isCleanup |
| * true if the task is cleanup attempt, false otherwise. |
| */ |
| public synchronized void setIsCleanup(boolean isCleanup) { |
| this.isCleanup = isCleanup; |
| } |
| |
| /** |
| * Get whether task is cleanup attempt or not. |
| * |
| * @return true if the task is cleanup attempt, false otherwise. |
| */ |
| public synchronized boolean getIsCleanup() { |
| return isCleanup; |
| } |
| } |