Package org.apache.hadoop.hdfs.server.datanode

Class BlockScanner

java.lang.Object

org.apache.hadoop.hdfs.server.datanode.BlockScanner

@Private
public class BlockScanner
extends Object

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	BlockScanner.Servlet

Field Summary

Fields

Modifier and Type	Field	Description
static final org.slf4j.Logger	LOG

Constructor Summary

Constructors

Constructor	Description
BlockScanner(DataNode datanode)
BlockScanner(DataNode datanode, org.apache.hadoop.conf.Configuration conf)

Method Summary

Modifier and Type	Method	Description
void	addVolumeScanner(FsVolumeReference ref)	Set up a scanner for the given block pool and volume.
long	getJoinVolumeScannersTimeOutMs()
boolean	hasAnyRegisteredScanner()	Returns true if there is any scanner thread registered.
boolean	isEnabled()	Returns true if the block scanner is enabled.
void	removeAllVolumeScanners()	Stops and removes all volume scanners.
void	removeVolumeScanner(FsVolumeSpi volume)	Stops and removes a volume scanner.
void	setJoinVolumeScannersTimeOutMs(long joinScannersTimeOutMs)

Methods inherited from class java.lang.Object

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

Field Details

LOG

public static final org.slf4j.Logger LOG

Constructor Details

BlockScanner

public BlockScanner(DataNode datanode)

BlockScanner

public BlockScanner(DataNode datanode,
 org.apache.hadoop.conf.Configuration conf)

Method Details

isEnabled

public boolean isEnabled()

Returns true if the block scanner is enabled. If the block scanner is disabled, no volume scanners will be created, and no threads will start.

hasAnyRegisteredScanner

public boolean hasAnyRegisteredScanner()

Returns true if there is any scanner thread registered.

addVolumeScanner

public void addVolumeScanner(FsVolumeReference ref)

Set up a scanner for the given block pool and volume.

Parameters:

ref - A reference to the volume.

removeVolumeScanner

public void removeVolumeScanner(FsVolumeSpi volume)

Stops and removes a volume scanner. This function will block until the volume scanner has stopped.

Parameters:

volume - The volume to remove.

removeAllVolumeScanners

public void removeAllVolumeScanners()

Stops and removes all volume scanners. This function is called on shutdown. It will return even if some of the scanners don't terminate in time. Since the scanners are daemon threads and do not alter the block content, it is safe to ignore such conditions on shutdown.

getJoinVolumeScannersTimeOutMs

public long getJoinVolumeScannersTimeOutMs()

setJoinVolumeScannersTimeOutMs

public void setJoinVolumeScannersTimeOutMs(long joinScannersTimeOutMs)