Package org.apache.hadoop.hbase.regionserver

Class ShutdownHook

java.lang.Object

org.apache.hadoop.hbase.regionserver.ShutdownHook

@Private
public class ShutdownHook
extends Object

Manage regionserver shutdown hooks.

See Also:

• install(Configuration, FileSystem, Stoppable, Thread)

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
(package private) static class	ShutdownHook.DoNothingStoppable
(package private) static class	ShutdownHook.DoNothingThread
private static class	ShutdownHook.ShutdownHookThread

Field Summary

Fields

Modifier and Type	Field	Description
private static final String	CLIENT_FINALIZER_DATA_METHOD
static final String	FS_SHUTDOWN_HOOK_WAIT	Key for a long configuration on how much time to wait on the fs shutdown hook.
private static final Map<Runnable,Integer>	fsShutdownHooks	A place for keeping track of all the filesystem shutdown hooks that need to be executed after the last regionserver referring to a given filesystem stops.
private static final org.slf4j.Logger	LOG
static final String	RUN_SHUTDOWN_HOOK	Key for boolean configuration whose default is true.

Constructor Summary

Constructors

Constructor	Description
ShutdownHook()

Method Summary

Modifier and Type	Method	Description
static void	install(org.apache.hadoop.conf.Configuration conf, org.apache.hadoop.fs.FileSystem fs, Stoppable stop, Thread threadToJoin)	Install a shutdown hook that calls stop on the passed Stoppable and then thread joins against the passed threadToJoin.
static void	main(String[] args)	Main to test basic functionality.
private static Runnable	suppressHdfsShutdownHook(org.apache.hadoop.fs.FileSystem fs)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

LOG

private static final org.slf4j.Logger LOG

CLIENT_FINALIZER_DATA_METHOD

private static final String CLIENT_FINALIZER_DATA_METHOD

See Also:

• Constant Field Values

RUN_SHUTDOWN_HOOK

public static final String RUN_SHUTDOWN_HOOK

Key for boolean configuration whose default is true.

See Also:

• Constant Field Values

FS_SHUTDOWN_HOOK_WAIT

public static final String FS_SHUTDOWN_HOOK_WAIT

Key for a long configuration on how much time to wait on the fs shutdown hook. Default is 30 seconds.

See Also:

• Constant Field Values

fsShutdownHooks

private static final Map<Runnable,Integer> fsShutdownHooks

A place for keeping track of all the filesystem shutdown hooks that need to be executed after the last regionserver referring to a given filesystem stops. We keep track of the # of regionserver references in values of the map.

Constructor Details

ShutdownHook

public ShutdownHook()

Method Details

install

public static void install(org.apache.hadoop.conf.Configuration conf,
 org.apache.hadoop.fs.FileSystem fs,
 Stoppable stop,
 Thread threadToJoin)

Install a shutdown hook that calls stop on the passed Stoppable and then thread joins against the passed threadToJoin. When this thread completes, it then runs the hdfs thread (This install removes the hdfs shutdown hook keeping a handle on it to run it after threadToJoin has stopped).

To suppress all shutdown hook handling -- both the running of the regionserver hook and of the hdfs hook code -- set RUN_SHUTDOWN_HOOK in Configuration to false. This configuration value is checked when the hook code runs.

Parameters:

fs - Instance of Filesystem used by the RegionServer

stop - Installed shutdown hook will call stop against this passed Stoppable instance.

threadToJoin - After calling stop on stop will then join this thread.

suppressHdfsShutdownHook

private static Runnable suppressHdfsShutdownHook(org.apache.hadoop.fs.FileSystem fs)

main

public static void main(String[] args)
                 throws IOException

Main to test basic functionality. Run with clean hadoop 0.20 and hadoop 0.21 and cloudera patched hadoop to make sure our shutdown hook handling works for all compbinations. Pass '-Dhbase.shutdown.hook=false' to test turning off the running of shutdown hooks.

Throws:

IOException