abhishekshivanna commented on a change in pull request #1151: [SAMZA-2198] Fix deadlock in container signal handler URL: https://github.com/apache/samza/pull/1151#discussion_r325262884
########## File path: samza-core/src/main/java/org/apache/samza/runtime/ClusterBasedProcessorLifecycleListener.java ########## @@ -0,0 +1,133 @@ +/* + * 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.samza.runtime; + +import com.google.common.annotations.VisibleForTesting; +import java.util.concurrent.CountDownLatch; +import java.util.concurrent.TimeUnit; +import org.apache.samza.config.Config; +import org.apache.samza.config.TaskConfig; +import org.apache.samza.container.SamzaContainerListener; +import org.apache.samza.util.ThreadUtil; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + + +public class ClusterBasedProcessorLifecycleListener implements SamzaContainerListener { + private static final Logger log = LoggerFactory.getLogger(ClusterBasedProcessorLifecycleListener.class); + private final Runnable onSignal; + private Thread shutdownHookThread = null; + private CountDownLatch shutdownLatch = new CountDownLatch(1); + private TaskConfig taskConfig; + private ProcessorLifecycleListener processorLifecycleListener; + private volatile Throwable containerException = null; + + ClusterBasedProcessorLifecycleListener(Config config, ProcessorLifecycleListener processorLifecycleListener, + Runnable onSignal) { + this.taskConfig = new TaskConfig(config); + this.processorLifecycleListener = processorLifecycleListener; + this.onSignal = onSignal; + } + + @Override + public void beforeStart() { + log.info("Before starting the container."); + addShutdownHook(); + processorLifecycleListener.beforeStart(); + } + + @Override + public void afterStart() { + log.info("Container Started"); + processorLifecycleListener.afterStart(); + } + + @Override + public void afterStop() { + log.info("Container Stopped"); + processorLifecycleListener.afterStop(); + removeShutdownHook(); + shutdownLatch.countDown(); + } + + @Override + public void afterFailure(Throwable t) { + log.info("Container Failed"); + containerException = t; + processorLifecycleListener.afterFailure(t); + removeShutdownHook(); + shutdownLatch.countDown(); + } + + Throwable getContainerException() { + return containerException; + } + + private void removeShutdownHook() { + try { + if (shutdownHookThread != null) { + removeJVMShutdownHook(); + } + } catch (IllegalStateException e) { + // Thrown when then JVM is already shutting down, so safe to ignore. + } + } + + private void addShutdownHook() { + shutdownHookThread = new Thread("Samza Container Shutdown Hook Thread") { + @Override + public void run() { + long shutdownMs = taskConfig.getShutdownMs(); + log.info("Attempting to shutdown container from inside shutdownHook, will wait up to {} ms.", shutdownMs); + try { + onSignal.run(); + boolean hasShutdown = shutdownLatch.await(shutdownMs, TimeUnit.MILLISECONDS); + if (hasShutdown) { + log.info("Shutdown complete"); + } else { + log.error("Did not shut down within {} ms, exiting.", shutdownMs); + ThreadUtil.logThreadDump("Thread dump from Samza Container Shutdown Hook."); + } + } catch (InterruptedException e) { + log.error("Shutdown hook inturrupted while waiting on runLoop to shutdown"); + ThreadUtil.logThreadDump("Thread dump from Samza Container Shutdown Hook."); + } + } + }; + addJVMShutdownHook(); + } + + @VisibleForTesting + Thread getShutdownHookThread() { + return this.shutdownHookThread; + } + + @VisibleForTesting + void addJVMShutdownHook() { + Runtime.getRuntime().addShutdownHook(shutdownHookThread); Review comment: Makes sense. Fixed. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected] With regards, Apache Git Services
