Module org.elasticsearch.server

Package org.elasticsearch.cluster

Class ClusterStateUpdateTask

java.lang.Object

org.elasticsearch.cluster.ClusterStateUpdateTask

All Implemented Interfaces:

ClusterStateTaskListener

Direct Known Subclasses:

AckedClusterStateUpdateTask, MigrationResultsUpdateTask, SystemIndexMetadataUpgradeService.SystemIndexMetadataUpdateTask

public abstract class ClusterStateUpdateTask
extends Object
implements ClusterStateTaskListener

A task that can update the cluster state.

Constructor Summary

Constructors

Constructor	Description
ClusterStateUpdateTask()
ClusterStateUpdateTask(Priority priority)
ClusterStateUpdateTask(Priority priority, TimeValue timeout)
ClusterStateUpdateTask(TimeValue timeout)

Method Summary

Modifier and Type	Method	Description
void	clusterStateProcessed(ClusterState initialState, ClusterState newState)	Called when the result of the execute(org.elasticsearch.cluster.ClusterState) method has been processed properly by all listeners.
abstract ClusterState	execute(ClusterState currentState)	Computes the cluster state that results from executing this task on the given state.
final Priority	priority()
final TimeValue	timeout()	If the cluster state update task wasn't processed by the provided timeout, call ClusterStateTaskListener.onFailure(Exception).

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.elasticsearch.cluster.ClusterStateTaskListener

onFailure

Constructor Details

ClusterStateUpdateTask

public ClusterStateUpdateTask()

ClusterStateUpdateTask

public ClusterStateUpdateTask(Priority priority)

ClusterStateUpdateTask

public ClusterStateUpdateTask(TimeValue timeout)

ClusterStateUpdateTask

public ClusterStateUpdateTask(Priority priority,
 TimeValue timeout)

Method Details

execute

public abstract ClusterState execute(ClusterState currentState)
                              throws Exception

Computes the cluster state that results from executing this task on the given state. Returns the *same instance* if no change is required, which is an important and valuable optimisation since it short-circuits the whole publication process and saves a bunch of time and effort.

Throws:

Exception

clusterStateProcessed

public void clusterStateProcessed(ClusterState initialState,
 ClusterState newState)

Called when the result of the execute(org.elasticsearch.cluster.ClusterState) method has been processed properly by all listeners. The parameter is the state that was ultimately published. Implementations of this callback must not throw exceptions: an exception thrown here is logged by the master service at ERROR level and otherwise ignored, except in tests where it raises an AssertionError. If log-and-ignore is the right behaviour then implementations must do so themselves, typically using a more specific logger and at a less dramatic log level.

timeout

@Nullable
public final TimeValue timeout()

If the cluster state update task wasn't processed by the provided timeout, call ClusterStateTaskListener.onFailure(Exception). May return null to indicate no timeout is needed (default).

priority

public final Priority priority()