Package org.apache.accumulo.core.spi.balancer

Class TableLoadBalancer

java.lang.Object

org.apache.accumulo.core.spi.balancer.TableLoadBalancer

All Implemented Interfaces:

TabletBalancer

Direct Known Subclasses:

HostRegexTableLoadBalancer

public class TableLoadBalancer
extends Object
implements TabletBalancer

Since:

2.1.0

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.accumulo.core.spi.balancer.TabletBalancer

TabletBalancer.AssignmentParameters, TabletBalancer.BalanceParameters

Field Summary

Fields

Modifier and Type	Field	Description
protected BalancerEnvironment	environment

Constructor Summary

Constructors

Constructor	Description
TableLoadBalancer()

Method Summary

Modifier and Type	Method	Description
long	balance(TabletBalancer.BalanceParameters params)	Ask the balancer if any migrations are necessary.
void	getAssignments(TabletBalancer.AssignmentParameters params)	Assign tablets to tablet servers.
protected TabletBalancer	getBalancerForTable(TableId tableId)
protected String	getLoadBalancerClassNameForTable(TableId table)
void	init(BalancerEnvironment balancerEnvironment)	Initialize the TabletBalancer.

Methods inherited from class java.lang.Object

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

Field Details

environment

protected BalancerEnvironment environment

Constructor Details

TableLoadBalancer

public TableLoadBalancer()

Method Details

init

public void init(BalancerEnvironment balancerEnvironment)

Description copied from interface: TabletBalancer

Initialize the TabletBalancer. This gives the balancer the opportunity to read the configuration.

Specified by:

init in interface TabletBalancer

getLoadBalancerClassNameForTable

protected String getLoadBalancerClassNameForTable(TableId table)

getBalancerForTable

protected TabletBalancer getBalancerForTable(TableId tableId)

getAssignments

public void getAssignments(TabletBalancer.AssignmentParameters params)

Description copied from interface: TabletBalancer

Assign tablets to tablet servers. This method is called whenever the manager finds tablets that are unassigned.

Specified by:

getAssignments in interface TabletBalancer

balance

public long balance(TabletBalancer.BalanceParameters params)

Description copied from interface: TabletBalancer

Ask the balancer if any migrations are necessary. If the balancer is going to self-abort due to some environmental constraint (e.g. it requires some minimum number of tservers, or a maximum number of outstanding migrations), it should issue a log message to alert operators. The message should be at WARN normally and at ERROR if the balancer knows that the problem can not self correct. It should not issue these messages more than once a minute. This method will not be called when there are unassigned tablets.

Specified by:

balance in interface TabletBalancer

Returns:

the time, in milliseconds, to wait before re-balancing.