Package org.apache.lucene.index

Class MergeRateLimiter

java.lang.Object

org.apache.lucene.store.RateLimiter

org.apache.lucene.index.MergeRateLimiter

public class MergeRateLimiter
extends RateLimiter

This is the RateLimiter that IndexWriter assigns to each running merge, to give MergeSchedulers ionice like control.

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.lucene.store.RateLimiter

RateLimiter.SimpleRateLimiter

Field Summary

Fields

Modifier and Type	Field	Description
private long	lastNS
private static long	MAX_PAUSE_NS
private double	mbPerSec
private MergePolicy.OneMergeProgress	mergeProgress
private static int	MIN_PAUSE_CHECK_MSEC
private static long	MIN_PAUSE_NS
private long	minPauseCheckBytes
private java.util.concurrent.atomic.AtomicLong	totalBytesWritten

Constructor Summary

Constructors

Constructor	Description
MergeRateLimiter(MergePolicy.OneMergeProgress mergeProgress)	Sole constructor.

Method Summary

Modifier and Type	Method	Description
double	getMBPerSec()	The current MB per second rate limit.
long	getMinPauseCheckBytes()	How many bytes caller should add up itself before invoking RateLimiter.pause(long).
long	getTotalBytesWritten()	Returns total bytes written by this merge.
long	getTotalPausedNS()	Total NS merge was paused to rate limit IO.
long	getTotalStoppedNS()	Total NS merge was stopped.
private long	maybePause(long bytes, long curNS)	Returns the number of nanoseconds spent in a paused state or -1 if no pause was applied.
long	pause(long bytes)	Pauses, if necessary, to keep the instantaneous IO rate at or below the target.
void	setMBPerSec(double mbPerSec)	Sets an updated MB per second rate limit.

Methods inherited from class java.lang.Object

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

Field Detail

MIN_PAUSE_CHECK_MSEC

private static final int MIN_PAUSE_CHECK_MSEC

See Also:

Constant Field Values

MIN_PAUSE_NS

private static final long MIN_PAUSE_NS

MAX_PAUSE_NS

private static final long MAX_PAUSE_NS

mbPerSec

private volatile double mbPerSec

minPauseCheckBytes

private volatile long minPauseCheckBytes

lastNS

private long lastNS

totalBytesWritten

private java.util.concurrent.atomic.AtomicLong totalBytesWritten

mergeProgress

private final MergePolicy.OneMergeProgress mergeProgress

Constructor Detail

MergeRateLimiter

public MergeRateLimiter(MergePolicy.OneMergeProgress mergeProgress)

Sole constructor.

Method Detail

setMBPerSec

public void setMBPerSec(double mbPerSec)

Description copied from class: RateLimiter

Sets an updated MB per second rate limit. A subclass is allowed to perform dynamic updates of the rate limit during use.

Specified by:

setMBPerSec in class RateLimiter

getMBPerSec

public double getMBPerSec()

Description copied from class: RateLimiter

The current MB per second rate limit.

Specified by:

getMBPerSec in class RateLimiter

getTotalBytesWritten

public long getTotalBytesWritten()

Returns total bytes written by this merge.

pause

public long pause(long bytes)
           throws MergePolicy.MergeAbortedException

Description copied from class: RateLimiter

Pauses, if necessary, to keep the instantaneous IO rate at or below the target.

Note: the implementation is thread-safe

Specified by:

pause in class RateLimiter

Returns:

the pause time in nano seconds

Throws:

MergePolicy.MergeAbortedException

getTotalStoppedNS

public long getTotalStoppedNS()

Total NS merge was stopped.

getTotalPausedNS

public long getTotalPausedNS()

Total NS merge was paused to rate limit IO.

maybePause

private long maybePause(long bytes,
                        long curNS)
                 throws MergePolicy.MergeAbortedException

Returns the number of nanoseconds spent in a paused state or -1 if no pause was applied. If the thread needs pausing, this method delegates to the linked MergePolicy.OneMergeProgress.

Throws:

MergePolicy.MergeAbortedException

getMinPauseCheckBytes

public long getMinPauseCheckBytes()

Description copied from class: RateLimiter

How many bytes caller should add up itself before invoking RateLimiter.pause(long). NOTE: The value returned by this method may change over time and is not guaranteed to be constant throughout the lifetime of the RateLimiter. Users are advised to refresh their local values with calls to this method to ensure consistency.

Specified by:

getMinPauseCheckBytes in class RateLimiter