Example usage for org.apache.hadoop.util ShutdownHookManager removeShutdownHook

Introduction

In this page you can find the example usage for org.apache.hadoop.util ShutdownHookManager removeShutdownHook.

Prototype

@InterfaceAudience.Public
@InterfaceStability.Stable
public boolean removeShutdownHook(Runnable shutdownHook) 

Source Link

Document

Removes a shutdownHook.

Usage

From source file:co.cask.cdap.app.runtime.spark.SparkRuntimeService.java

License:Apache License

/**
 * Cleanup all shutdown hooks added by Spark and execute them directly.
 * This is needed so that for CDAP standalone, it won't leak memory through shutdown hooks.
 *//*from  ww  w. ja va2  s .com*/
private void cleanupShutdownHooks() {
    // With Hadoop 2, Spark uses the Hadoop ShutdownHookManager
    ShutdownHookManager manager = ShutdownHookManager.get();
    try {
        // Use reflection to get the shutdown hooks
        Method getShutdownHooksInOrder = manager.getClass().getDeclaredMethod("getShutdownHooksInOrder");
        if (!Collection.class.isAssignableFrom(getShutdownHooksInOrder.getReturnType())) {
            LOG.warn("Unsupported method {}. Spark shutdown hooks cleanup skipped.", getShutdownHooksInOrder);
            return;
        }
        getShutdownHooksInOrder.setAccessible(true);

        // Filter out hooks that are defined in the same SparkRunnerClassLoader as this SparkProgramRunner class
        // This is for the case when there are concurrent Spark job running in the same VM
        List<Runnable> hooks = ImmutableList.copyOf(Iterables.filter(
                Iterables.filter((Collection<?>) getShutdownHooksInOrder.invoke(manager), Runnable.class),
                new Predicate<Runnable>() {
                    @Override
                    public boolean apply(Runnable runnable) {
                        return runnable.getClass().getClassLoader() == SparkRuntimeService.this.getClass()
                                .getClassLoader();
                    }
                }));

        for (Runnable hook : hooks) {
            LOG.debug("Running Spark shutdown hook {}", hook);
            hook.run();
            manager.removeShutdownHook(hook);
        }

    } catch (Exception e) {
        LOG.warn("Failed to cleanup Spark shutdown hooks.", e);
    }
}

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