Package org.apache.hadoop.hbase.master.balancer

Class StoreFileTableSkewCostFunction

java.lang.Object

org.apache.hadoop.hbase.master.balancer.CostFunction

org.apache.hadoop.hbase.master.balancer.CostFromRegionLoadFunction

org.apache.hadoop.hbase.master.balancer.StoreFileTableSkewCostFunction

@Private
public class StoreFileTableSkewCostFunction
extends CostFromRegionLoadFunction

Lightweight cost function that mirrors TableSkewCostFunction but aggregates storefile sizes (in MB) per table using the CostFromRegionLoadFunction framework. For each table, it computes a per-server aggregated storefile size by summing the average storefile size for each region (if there are multiple load metrics, it averages them). The imbalance cost (as computed by DoubleArrayCost) is then used to drive the balancer to reduce differences between servers.

Field Summary

Fields

Modifier and Type	Field	Description
private DoubleArrayCost[]	costsPerTable
private static final float	DEFAULT_STOREFILE_TABLE_SKEW_COST
private static final String	STOREFILE_TABLE_SKEW_COST_KEY

Fields inherited from class org.apache.hadoop.hbase.master.balancer.CostFunction

cluster

Constructor Summary

Constructors

Constructor	Description
StoreFileTableSkewCostFunction(org.apache.hadoop.conf.Configuration conf)

Method Summary

Modifier and Type	Method	Description
protected double	cost()
protected double	getCostFromRl(BalancerRegionLoad rl)
void	prepare(BalancerClusterState cluster)	Called once per LB invocation to give the cost function to initialize it's state, and perform any costly calculation.
protected void	regionMoved(int region, int oldServer, int newServer)
private void	updateStoreFilePerServerPerTableCosts(int newServer, int tableIdx, double[] costs)

Methods inherited from class org.apache.hadoop.hbase.master.balancer.CostFromRegionLoadFunction

getRegionLoadCost

Methods inherited from class org.apache.hadoop.hbase.master.balancer.CostFunction

getCostEpsilon, getMultiplier, isNeeded, postAction, scale, setMultiplier, updateWeight

Methods inherited from class java.lang.Object

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

Field Details

STOREFILE_TABLE_SKEW_COST_KEY

private static final String STOREFILE_TABLE_SKEW_COST_KEY

See Also:

• Constant Field Values

DEFAULT_STOREFILE_TABLE_SKEW_COST

private static final float DEFAULT_STOREFILE_TABLE_SKEW_COST

See Also:

• Constant Field Values

costsPerTable

private DoubleArrayCost[] costsPerTable

Constructor Details

StoreFileTableSkewCostFunction

public StoreFileTableSkewCostFunction(org.apache.hadoop.conf.Configuration conf)

Method Details

prepare

public void prepare(BalancerClusterState cluster)

Description copied from class: CostFunction

Called once per LB invocation to give the cost function to initialize it's state, and perform any costly calculation.

Overrides:

prepare in class CostFromRegionLoadFunction

regionMoved

protected void regionMoved(int region,
 int oldServer,
 int newServer)

Overrides:

regionMoved in class CostFromRegionLoadFunction

updateStoreFilePerServerPerTableCosts

private void updateStoreFilePerServerPerTableCosts(int newServer,
 int tableIdx,
 double[] costs)

cost

protected double cost()

Overrides:

cost in class CostFromRegionLoadFunction

getCostFromRl

protected double getCostFromRl(BalancerRegionLoad rl)

Specified by:

getCostFromRl in class CostFromRegionLoadFunction