Package org.apache.hadoop.hbase.io.hfile

Class PrefetchExecutor

java.lang.Object

org.apache.hadoop.hbase.io.hfile.PrefetchExecutor

@Private
public final class PrefetchExecutor
extends Object

Field Summary

Fields

Modifier and Type	Field	Description
private static final org.slf4j.Logger	LOG
static final String	PREFETCH_DELAY	Wait time in miliseconds before executing prefetch
static final String	PREFETCH_DELAY_VARIATION
static final float	PREFETCH_DELAY_VARIATION_DEFAULT_VALUE
private static int	prefetchDelayMillis	Delay before beginning prefetch
private static float	prefetchDelayVariation	Variation in prefetch delay times, to mitigate stampedes
private static final ScheduledExecutorService	prefetchExecutorPool	Executor pool shared among all HFiles for block prefetch
private static final Map<org.apache.hadoop.fs.Path,Future<?>>	prefetchFutures	Futures for tracking block prefetch activity
private static final Pattern	prefetchPathExclude
private static final Map<org.apache.hadoop.fs.Path,Runnable>	prefetchRunnable	Runnables for resetting the prefetch activity

Constructor Summary

Constructors

Modifier	Constructor	Description
private	PrefetchExecutor()

Method Summary

Modifier and Type	Method	Description
static void	cancel(org.apache.hadoop.fs.Path path)
static void	complete(org.apache.hadoop.fs.Path path)
(package private) static ScheduledExecutorService	getExecutorPool()
static int	getPrefetchDelay()
(package private) static Map<org.apache.hadoop.fs.Path,Future<?>>	getPrefetchFutures()
(package private) static Map<org.apache.hadoop.fs.Path,Runnable>	getPrefetchRunnable()
static boolean	isCompleted(org.apache.hadoop.fs.Path path)
(package private) static boolean	isPrefetchStarted()
static void	loadConfiguration(org.apache.hadoop.conf.Configuration conf)
static void	request(org.apache.hadoop.fs.Path path, Runnable runnable)

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

PREFETCH_DELAY

public static final String PREFETCH_DELAY

Wait time in miliseconds before executing prefetch

See Also:

• Constant Field Values

PREFETCH_DELAY_VARIATION

public static final String PREFETCH_DELAY_VARIATION

See Also:

• Constant Field Values

PREFETCH_DELAY_VARIATION_DEFAULT_VALUE

public static final float PREFETCH_DELAY_VARIATION_DEFAULT_VALUE

See Also:

• Constant Field Values

prefetchFutures

private static final Map<org.apache.hadoop.fs.Path,Future<?>> prefetchFutures

Futures for tracking block prefetch activity

prefetchRunnable

private static final Map<org.apache.hadoop.fs.Path,Runnable> prefetchRunnable

Runnables for resetting the prefetch activity

prefetchExecutorPool

private static final ScheduledExecutorService prefetchExecutorPool

Executor pool shared among all HFiles for block prefetch

prefetchDelayMillis

private static int prefetchDelayMillis

Delay before beginning prefetch

prefetchDelayVariation

private static float prefetchDelayVariation

Variation in prefetch delay times, to mitigate stampedes

prefetchPathExclude

private static final Pattern prefetchPathExclude

Constructor Details

PrefetchExecutor

private PrefetchExecutor()

Method Details

request

public static void request(org.apache.hadoop.fs.Path path,
 Runnable runnable)

complete

public static void complete(org.apache.hadoop.fs.Path path)

cancel

public static void cancel(org.apache.hadoop.fs.Path path)

isCompleted

public static boolean isCompleted(org.apache.hadoop.fs.Path path)

getExecutorPool

static ScheduledExecutorService getExecutorPool()

getPrefetchFutures

static Map<org.apache.hadoop.fs.Path,Future<?>> getPrefetchFutures()

getPrefetchRunnable

static Map<org.apache.hadoop.fs.Path,Runnable> getPrefetchRunnable()

isPrefetchStarted

static boolean isPrefetchStarted()

getPrefetchDelay

public static int getPrefetchDelay()

loadConfiguration

public static void loadConfiguration(org.apache.hadoop.conf.Configuration conf)