org.apache.hadoop.hbase.master.normalizer

Interface RegionNormalizer

All Superinterfaces:

org.apache.hadoop.conf.Configurable

All Known Implementing Classes:

SimpleRegionNormalizer

@InterfaceAudience.Private
 @InterfaceStability.Evolving
public interface RegionNormalizer
extends org.apache.hadoop.conf.Configurable

Performs "normalization" of regions of a table, making sure that suboptimal choice of split keys doesn't leave cluster in a situation when some regions are substantially larger than others for considerable amount of time. Users who want to use this feature could either use default SimpleRegionNormalizer or plug in their own implementation. Please note that overly aggressive normalization rules (attempting to make all regions perfectly equal in size) could potentially lead to "split/merge storms".

Method Summary

Modifier and Type	Method and Description
List<NormalizationPlan>	computePlansForTable(TableName table) Computes a list of normalizer actions to perform on the target 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	setMasterServices(MasterServices masterServices) Set the master service.

Methods inherited from interface org.apache.hadoop.conf.Configurable

getConf, setConf

Method Detail

setMasterServices

void setMasterServices(MasterServices masterServices)

Set the master service. Must be called before first call to computePlansForTable(TableName).

Parameters:

masterServices - master services to use

computePlansForTable

List<NormalizationPlan> computePlansForTable(TableName table)
                                      throws HBaseIOException

Computes a list of normalizer actions to perform on the target table. This is the primary entry-point from the Master driving a normalization activity.

Parameters:

table - table to normalize

Returns:

A list of the normalization actions to perform, or an empty list if there's nothing to do.

Throws:

HBaseIOException

planSkipped

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

Parameters:

hri - the region which is involved in the plan

type - type of plan

getSkippedCount

long getSkippedCount(NormalizationPlan.PlanType type)

Parameters:

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

Returns:

the count of plans of specified type which were skipped