Package org.elasticsearch.cluster

Interface ClusterStateTaskExecutor<T>

All Known Implementing Classes:

AckedClusterStateUpdateTask, ClusterStateUpdateTask, JoinTaskExecutor, LocalClusterUpdateTask, NodeRemovalClusterStateTaskExecutor, ShardStateAction.ShardFailedClusterStateTaskExecutor, ShardStateAction.ShardStartedClusterStateTaskExecutor, SystemIndexMetadataUpgradeService.SystemIndexMetadataUpdateTask

public interface ClusterStateTaskExecutor<T>

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static class	ClusterStateTaskExecutor.ClusterTasksResult<T>	Represents the result of a batched execution of cluster state update tasks
static class	ClusterStateTaskExecutor.TaskResult

Method Summary

Modifier and Type	Method	Description
default void	clusterStatePublished(ClusterChangedEvent clusterChangedEvent)	Callback invoked after new cluster state is published.
default String	describeTasks(List<T> tasks)	Builds a concise description of a list of tasks (to be used in logging etc.).
ClusterStateTaskExecutor.ClusterTasksResult<T>	execute(ClusterState currentState, List<T> tasks)	Update the cluster state based on the current state and the given tasks.
default boolean	runOnlyOnMaster()	indicates whether this executor should only run if the current node is master

Method Details

execute

ClusterStateTaskExecutor.ClusterTasksResult<T> execute(ClusterState currentState,
 List<T> tasks)
                                                throws Exception

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

Throws:

Exception

runOnlyOnMaster

default boolean runOnlyOnMaster()

indicates whether this executor should only run if the current node is master

clusterStatePublished

default void clusterStatePublished(ClusterChangedEvent clusterChangedEvent)

Callback invoked after new cluster state is published. Note that this method is not invoked if the cluster state was not updated. Note that this method will be executed using system context.

Parameters:

clusterChangedEvent - the change event for this cluster state change, containing both old and new states

describeTasks

default String describeTasks(List<T> tasks)

Builds a concise description of a list of tasks (to be used in logging etc.). Note that the tasks given are not necessarily the same as those that will be passed to execute(ClusterState, List). but are guaranteed to be a subset of them. This method can be called multiple times with different lists before execution. This allows groupd task description but the submitting source.