Package org.apache.hadoop.hbase.regionserver

Class BusyRegionSplitPolicy

java.lang.Object

org.apache.hadoop.conf.Configured

org.apache.hadoop.hbase.regionserver.RegionSplitPolicy

org.apache.hadoop.hbase.regionserver.ConstantSizeRegionSplitPolicy

org.apache.hadoop.hbase.regionserver.IncreasingToUpperBoundRegionSplitPolicy

org.apache.hadoop.hbase.regionserver.BusyRegionSplitPolicy

All Implemented Interfaces:

org.apache.hadoop.conf.Configurable

@LimitedPrivate("Configuration")
public class BusyRegionSplitPolicy
extends IncreasingToUpperBoundRegionSplitPolicy

This class represents a split policy which makes the split decision based on how busy a region is. The metric that is used here is the fraction of total write requests that are blocked due to high memstore utilization. This fractional rate is calculated over a running window of "hbase.busy.policy.aggWindow" milliseconds. The rate is a time-weighted aggregated average of the rate in the current window and the true average rate in the previous window.

Field Summary

Fields

Modifier and Type	Field	Description
private long	aggregationWindow
private float	blockedRate
private long	blockedRequestCount
static final long	DEFAULT_AGGREGATION_WINDOW
static final float	DEFAULT_MAX_BLOCKED_REQUESTS
static final long	DEFAULT_MIN_AGE_MS
private static final org.slf4j.Logger	LOG
private float	maxBlockedRequests
private long	minAge
private long	prevTime
private HRegion	region
private long	startTime
private long	writeRequestCount

Fields inherited from class org.apache.hadoop.hbase.regionserver.IncreasingToUpperBoundRegionSplitPolicy

initialSize

Fields inherited from class org.apache.hadoop.hbase.regionserver.ConstantSizeRegionSplitPolicy

overallHRegionFiles

Constructor Summary

Constructors

Constructor	Description
BusyRegionSplitPolicy()

Method Summary

Modifier and Type	Method	Description
protected void	configureForRegion(HRegion region)	Upon construction, this method will be called with the region to be governed.
private void	init()
protected boolean	shouldSplit()	Returns true if the specified region should be split.
String	toString()
private float	updateRate()	Update the blocked request rate based on number of blocked and total write requests in the last aggregation window, or since last call to this method, whichever is farthest in time.

Methods inherited from class org.apache.hadoop.hbase.regionserver.IncreasingToUpperBoundRegionSplitPolicy

getSizeToCheck

Methods inherited from class org.apache.hadoop.hbase.regionserver.ConstantSizeRegionSplitPolicy

getDesiredMaxFileSize, isExceedSize, positiveJitterRate

Methods inherited from class org.apache.hadoop.hbase.regionserver.RegionSplitPolicy

canSplit, create, getSplitPoint, getSplitPolicyClass, skipStoreFileRangeCheck

Methods inherited from class org.apache.hadoop.conf.Configured

getConf, setConf

Methods inherited from class java.lang.Object

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

Field Details

LOG

private static final org.slf4j.Logger LOG

maxBlockedRequests

private float maxBlockedRequests

DEFAULT_MAX_BLOCKED_REQUESTS

public static final float DEFAULT_MAX_BLOCKED_REQUESTS

See Also:

• Constant Field Values

minAge

private long minAge

DEFAULT_MIN_AGE_MS

public static final long DEFAULT_MIN_AGE_MS

See Also:

• Constant Field Values

aggregationWindow

private long aggregationWindow

DEFAULT_AGGREGATION_WINDOW

public static final long DEFAULT_AGGREGATION_WINDOW

See Also:

• Constant Field Values

region

private HRegion region

prevTime

private long prevTime

startTime

private long startTime

writeRequestCount

private long writeRequestCount

blockedRequestCount

private long blockedRequestCount

blockedRate

private float blockedRate

Constructor Details

BusyRegionSplitPolicy

public BusyRegionSplitPolicy()

Method Details

toString

public String toString()

Overrides:

toString in class IncreasingToUpperBoundRegionSplitPolicy

configureForRegion

protected void configureForRegion(HRegion region)

Description copied from class: RegionSplitPolicy

Upon construction, this method will be called with the region to be governed. It will be called once and only once.

Overrides:

configureForRegion in class IncreasingToUpperBoundRegionSplitPolicy

init

private void init()

shouldSplit

protected boolean shouldSplit()

Description copied from class: RegionSplitPolicy

Returns true if the specified region should be split.

Overrides:

shouldSplit in class IncreasingToUpperBoundRegionSplitPolicy

updateRate

private float updateRate()

Update the blocked request rate based on number of blocked and total write requests in the last aggregation window, or since last call to this method, whichever is farthest in time. Uses weighted rate calculation based on the previous rate and new data.

Returns:

Updated blocked request rate.