org.apache.accumulo.server.master.balancer

Class ChaoticLoadBalancer

java.lang.Object

org.apache.accumulo.server.master.balancer.TabletBalancer

org.apache.accumulo.server.master.balancer.ChaoticLoadBalancer

public class ChaoticLoadBalancer
extends TabletBalancer

A chaotic load balancer used for testing. It constantly shuffles tablets, preventing them from resting in a single location for very long. This is not designed for performance, do not use on production systems. I'm calling it the LokiLoadBalancer.

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.accumulo.server.master.balancer.TabletBalancer

TabletBalancer.BalancerProblem, TabletBalancer.NoTservers, TabletBalancer.OutstandingMigrations

Field Summary

Fields

Modifier and Type	Field and Description
protected TabletBalancer.OutstandingMigrations	outstandingMigrations

Fields inherited from class org.apache.accumulo.server.master.balancer.TabletBalancer

configuration, TIME_BETWEEN_BALANCER_WARNINGS

Constructor Summary

Constructors

Constructor and Description
ChaoticLoadBalancer()

Method Summary

Methods

Modifier and Type	Method and Description
long	balance(SortedMap<TServerInstance,TabletServerStatus> current, Set<KeyExtent> migrations, List<TabletMigration> migrationsOut) Will balance randomly, maintaining distribution
void	getAssignments(SortedMap<TServerInstance,TabletServerStatus> current, Map<KeyExtent,TServerInstance> unassigned, Map<KeyExtent,TServerInstance> assignments) Assign tablets to tablet servers.
void	init(ServerConfiguration conf) Initialize the TabletBalancer.

Methods inherited from class org.apache.accumulo.server.master.balancer.TabletBalancer

checkMigrationSanity, constraintNotMet, getOnlineTabletsForTable, resetBalancerErrors

Methods inherited from class java.lang.Object

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

Field Detail

outstandingMigrations

protected final TabletBalancer.OutstandingMigrations outstandingMigrations

Constructor Detail

ChaoticLoadBalancer

public ChaoticLoadBalancer()

Method Detail

getAssignments

public void getAssignments(SortedMap<TServerInstance,TabletServerStatus> current,
                  Map<KeyExtent,TServerInstance> unassigned,
                  Map<KeyExtent,TServerInstance> assignments)

Description copied from class: TabletBalancer

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

Specified by:

getAssignments in class TabletBalancer

Parameters:

current - The current table-summary state of all the online tablet servers. Read-only. The TabletServerStatus for each server may be null if the tablet server has not yet responded to a recent request for status.

unassigned - A map from unassigned tablet to the last known tablet server. Read-only.

assignments - A map from tablet to assigned server. Write-only.

balance

public long balance(SortedMap<TServerInstance,TabletServerStatus> current,
           Set<KeyExtent> migrations,
           List<TabletMigration> migrationsOut)

Will balance randomly, maintaining distribution

Specified by:

balance in class TabletBalancer

Parameters:

current - The current table-summary state of all the online tablet servers. Read-only.

migrations - the current set of migrations. Read-only.

migrationsOut - new migrations to perform; should not contain tablets in the current set of migrations. Write-only.

Returns:

the time, in milliseconds, to wait before re-balancing. This method will not be called when there are unassigned tablets.

init

public void init(ServerConfiguration conf)

Description copied from class: TabletBalancer

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

Overrides:

init in class TabletBalancer