Package org.elasticsearch.action.admin.cluster.desirednodes

Class DesiredNodesClusterStateTaskExecutor

java.lang.Object

org.elasticsearch.action.admin.cluster.desirednodes.DesiredNodesClusterStateTaskExecutor

All Implemented Interfaces:

ClusterStateTaskExecutor<ClusterStateUpdateTask>

public class DesiredNodesClusterStateTaskExecutor
extends Object
implements ClusterStateTaskExecutor<ClusterStateUpdateTask>

Nested Class Summary

Nested classes/interfaces inherited from interface org.elasticsearch.cluster.ClusterStateTaskExecutor

ClusterStateTaskExecutor.LegacyClusterTaskResultActionListener, ClusterStateTaskExecutor.SuccessIgnoringPublishListener, ClusterStateTaskExecutor.TaskContext<T extends ClusterStateTaskListener>

Constructor Summary

Constructors

Constructor	Description
DesiredNodesClusterStateTaskExecutor()

Method Summary

Modifier and Type	Method	Description
ClusterState	execute(ClusterState currentState, List<ClusterStateTaskExecutor.TaskContext<ClusterStateUpdateTask>> taskContexts)	Update the cluster state based on the current state and the given tasks.

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.ClusterStateTaskExecutor

clusterStatePublished, describeTasks, runOnlyOnMaster

Constructor Details

DesiredNodesClusterStateTaskExecutor

public DesiredNodesClusterStateTaskExecutor()

Method Details

execute

public ClusterState execute(ClusterState currentState,
 List<ClusterStateTaskExecutor.TaskContext<ClusterStateUpdateTask>> taskContexts)
                     throws Exception

Description copied from interface: ClusterStateTaskExecutor

Update the cluster state based on the current state and the given tasks. Return the *same instance* if no update should be published.

If this method throws an exception then the cluster state is unchanged and every task's ClusterStateTaskListener.onFailure(java.lang.Exception) method is called.

A common implementation pattern is to iterate through the tasks, constructing a new and updated ClusterState for each one. This works ok but beware that constructing a whole new ClusterState can be somewhat expensive, and there may sometimes be surprisingly many tasks to process in the batch. If it's possible to accumulate the effects of the tasks at a lower level then you should do that instead.

Specified by:

execute in interface ClusterStateTaskExecutor<ClusterStateUpdateTask>

Parameters:

currentState - The initial cluster state on which the tasks should be executed.

taskContexts - A ClusterStateTaskExecutor.TaskContext for each task in the batch. Implementations must complete every context in the list.

Returns:

The resulting cluster state after executing all the tasks. If {code currentState} is returned then no update is published.

Throws:

Exception