org.apache.hadoop.hbase.master.normalizer

Class SimpleRegionNormalizer

java.lang.Object

org.apache.hadoop.hbase.master.normalizer.SimpleRegionNormalizer

All Implemented Interfaces:

RegionNormalizer

@InterfaceAudience.Private
public class SimpleRegionNormalizer
extends Object
implements RegionNormalizer

Simple implementation of region normalizer. Logic in use:

1. Get all regions of a given table
2. Get avg size S of each region (by total size of store files reported in RegionMetrics)
3. Seek every single region one by one. If a region R0 is bigger than S * 2, it is kindly requested to split. Thereon evaluate the next region R1
4. Otherwise, if R0 + R1 is smaller than S, R0 and R1 are kindly requested to merge. Thereon evaluate the next region R2
5. Otherwise, R1 is evaluated

Region sizes are coarse and approximate on the order of megabytes. Additionally, "empty" regions (less than 1MB, with the previous note) are not merged away. This is by design to prevent normalization from undoing the pre-splitting of a table.

Constructor Summary

Constructors

Constructor and Description
SimpleRegionNormalizer()

Method Summary

Modifier and Type	Method and Description
List<NormalizationPlan>	computePlanForTable(TableName table) Computes next most "urgent" normalization action on the table.
long	getSkippedCount(NormalizationPlan.PlanType type)
void	planSkipped(RegionInfo hri, NormalizationPlan.PlanType type) Notification for the case where plan couldn't be executed due to constraint violation, such as namespace quota
void	setMasterRpcServices(MasterRpcServices masterRpcServices) Set the master RPC service.
void	setMasterServices(MasterServices masterServices) Set the master service.

Methods inherited from class java.lang.Object

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

Constructor Detail

SimpleRegionNormalizer

public SimpleRegionNormalizer()

Method Detail

setMasterServices

public void setMasterServices(MasterServices masterServices)

Set the master service.

Specified by:

setMasterServices in interface RegionNormalizer

Parameters:

masterServices - inject instance of MasterServices

setMasterRpcServices

public void setMasterRpcServices(MasterRpcServices masterRpcServices)

Description copied from interface: RegionNormalizer

Set the master RPC service. Must be called before first call to RegionNormalizer.computePlanForTable(TableName).

Specified by:

setMasterRpcServices in interface RegionNormalizer

Parameters:

masterRpcServices - master RPC services to use

planSkipped

public void planSkipped(RegionInfo hri,
                        NormalizationPlan.PlanType type)

Description copied from interface: RegionNormalizer

Notification for the case where plan couldn't be executed due to constraint violation, such as namespace quota

Specified by:

planSkipped in interface RegionNormalizer

Parameters:

hri - the region which is involved in the plan

type - type of plan

getSkippedCount

public long getSkippedCount(NormalizationPlan.PlanType type)

Specified by:

getSkippedCount in interface RegionNormalizer

Parameters:

type - type of plan for which skipped count is to be returned

Returns:

the count of plans of specified type which were skipped

computePlanForTable

public List<NormalizationPlan> computePlanForTable(TableName table)
                                            throws HBaseIOException

Computes next most "urgent" normalization action on the table. Action may be either a split, or a merge, or no action.

Specified by:

computePlanForTable in interface RegionNormalizer

Parameters:

table - table to normalize

Returns:

normalization plan to execute

Throws:

HBaseIOException