org.apache.hadoop.service.launcher.HadoopUncaughtExceptionHandler Maven / Gradle / Ivy
/*
* 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.service.launcher;
import java.lang.Thread.UncaughtExceptionHandler;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.hadoop.classification.InterfaceAudience.Public;
import org.apache.hadoop.classification.InterfaceStability.Evolving;
import org.apache.hadoop.util.ExitUtil;
import org.apache.hadoop.util.ShutdownHookManager;
/**
* This class is intended to be installed by calling
* {@link Thread#setDefaultUncaughtExceptionHandler(UncaughtExceptionHandler)}
* in the main entry point.
*
* The base class will always attempt to shut down the process if an Error
* was raised; the behavior on a standard Exception, raised outside
* process shutdown, is simply to log it.
*
* (Based on the class {@code YarnUncaughtExceptionHandler})
*/
@SuppressWarnings("UseOfSystemOutOrSystemErr")
@Public
@Evolving
public class HadoopUncaughtExceptionHandler
implements UncaughtExceptionHandler {
/**
* Logger.
*/
private static final Logger LOG = LoggerFactory.getLogger(
HadoopUncaughtExceptionHandler.class);
/**
* Delegate for simple exceptions.
*/
private final UncaughtExceptionHandler delegate;
/**
* Create an instance delegating to the supplied handler if
* the exception is considered "simple".
* @param delegate a delegate exception handler.
*/
public HadoopUncaughtExceptionHandler(UncaughtExceptionHandler delegate) {
this.delegate = delegate;
}
/**
* Basic exception handler -logs simple exceptions, then continues.
*/
public HadoopUncaughtExceptionHandler() {
this(null);
}
/**
* Uncaught exception handler.
* If an error is raised: shutdown
* The state of the system is unknown at this point -attempting
* a clean shutdown is dangerous. Instead: exit
* @param thread thread that failed
* @param exception the raised exception
*/
@Override
public void uncaughtException(Thread thread, Throwable exception) {
if (ShutdownHookManager.get().isShutdownInProgress()) {
LOG.error("Thread {} threw an error during shutdown: {}.",
thread.toString(),
exception,
exception);
} else if (exception instanceof Error) {
try {
LOG.error("Thread {} threw an error: {}. Shutting down",
thread.toString(),
exception,
exception);
} catch (Throwable err) {
// We don't want to not exit because of an issue with logging
}
if (exception instanceof OutOfMemoryError) {
// After catching an OOM java says it is undefined behavior, so don't
// even try to clean up or we can get stuck on shutdown.
try {
System.err.println("Halting due to Out Of Memory Error...");
} catch (Throwable err) {
// Again we don't want to exit because of logging issues.
}
ExitUtil.haltOnOutOfMemory((OutOfMemoryError) exception);
} else {
// error other than OutOfMemory
ExitUtil.ExitException ee =
ServiceLauncher.convertToExitException(exception);
ExitUtil.terminate(ee.status, ee);
}
} else {
// simple exception in a thread. There's a policy decision here:
// terminate the process vs. keep going after a thread has failed
// base implementation: do nothing but log
LOG.error("Thread {} threw an exception: {}",
thread.toString(),
exception,
exception);
if (delegate != null) {
delegate.uncaughtException(thread, exception);
}
}
}
}