org.apache.hadoop.yarn.util.AdHocLogDumper.java Source code

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Here is the source code for org.apache.hadoop.yarn.util.AdHocLogDumper.java

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/**
 * 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.yarn.util;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.commons.logging.impl.Log4JLogger;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
import org.apache.hadoop.yarn.exceptions.YarnRuntimeException;
import org.apache.log4j.*;

import java.io.File;
import java.io.IOException;
import java.util.*;

@InterfaceAudience.Private
@InterfaceStability.Unstable
public class AdHocLogDumper {

    private static final Log LOG = LogFactory.getLog(AdHocLogDumper.class);

    private String name;
    private String targetFilename;
    private Map<String, Priority> appenderLevels;
    private Level currentLogLevel;
    public static final String AD_HOC_DUMPER_APPENDER = "ad-hoc-dumper-appender";
    private static boolean logFlag = false;
    private static final Object lock = new Object();

    public AdHocLogDumper(String name, String targetFilename) {
        this.name = name;
        this.targetFilename = targetFilename;
        appenderLevels = new HashMap<>();
    }

    public void dumpLogs(String level, int timePeriod) throws YarnRuntimeException, IOException {
        synchronized (lock) {
            if (logFlag) {
                LOG.info("Attempt to dump logs when appender is already running");
                throw new YarnRuntimeException("Appender is already dumping logs");
            }
            Level targetLevel = Level.toLevel(level);
            Log log = LogFactory.getLog(name);
            appenderLevels.clear();
            if (log instanceof Log4JLogger) {
                Logger packageLogger = ((Log4JLogger) log).getLogger();
                currentLogLevel = packageLogger.getLevel();
                Level currentEffectiveLevel = packageLogger.getEffectiveLevel();

                // make sure we can create the appender first
                Layout layout = new PatternLayout("%d{ISO8601} %p %c: %m%n");
                FileAppender fApp;
                File file = new File(System.getProperty("yarn.log.dir"), targetFilename);
                try {
                    fApp = new FileAppender(layout, file.getAbsolutePath(), false);
                } catch (IOException ie) {
                    LOG.warn("Error creating file, can't dump logs to " + file.getAbsolutePath(), ie);
                    throw ie;
                }
                fApp.setName(AdHocLogDumper.AD_HOC_DUMPER_APPENDER);
                fApp.setThreshold(targetLevel);

                // get current threshold of all appenders and set it to the effective
                // level
                for (Enumeration appenders = Logger.getRootLogger().getAllAppenders(); appenders
                        .hasMoreElements();) {
                    Object obj = appenders.nextElement();
                    if (obj instanceof AppenderSkeleton) {
                        AppenderSkeleton appender = (AppenderSkeleton) obj;
                        appenderLevels.put(appender.getName(), appender.getThreshold());
                        appender.setThreshold(currentEffectiveLevel);
                    }
                }

                packageLogger.addAppender(fApp);
                LOG.info("Dumping adhoc logs for " + name + " to " + file.getAbsolutePath() + " for " + timePeriod
                        + " milliseconds");
                packageLogger.setLevel(targetLevel);
                logFlag = true;

                TimerTask restoreLogLevel = new RestoreLogLevel();
                Timer restoreLogLevelTimer = new Timer();
                restoreLogLevelTimer.schedule(restoreLogLevel, timePeriod);
            }
        }
    }

    class RestoreLogLevel extends TimerTask {
        @Override
        public void run() {
            Log log = LogFactory.getLog(name);
            if (log instanceof Log4JLogger) {
                Logger logger = ((Log4JLogger) log).getLogger();
                logger.removeAppender(AD_HOC_DUMPER_APPENDER);
                logger.setLevel(currentLogLevel);
                for (Enumeration appenders = Logger.getRootLogger().getAllAppenders(); appenders
                        .hasMoreElements();) {
                    Object obj = appenders.nextElement();
                    if (obj instanceof AppenderSkeleton) {
                        AppenderSkeleton appender = (AppenderSkeleton) obj;
                        appender.setThreshold(appenderLevels.get(appender.getName()));
                    }
                }
                logFlag = false;
                LOG.info("Done dumping adhoc logs for " + name);
            }
        }
    }
}