org.elasticsearch.cluster

Class ClusterStateObserver

java.lang.Object

org.elasticsearch.cluster.ClusterStateObserver

public class ClusterStateObserver
extends java.lang.Object

A utility class which simplifies interacting with the cluster state in cases where one tries to take action based on the current state but may want to wait for a new state and retry upon failure.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	ClusterStateObserver.Listener

Field Summary

Fields

Modifier and Type	Field and Description
protected org.apache.logging.log4j.Logger	logger

Constructor Summary

Constructors

Constructor and Description
ClusterStateObserver(ClusterService clusterService, org.apache.logging.log4j.Logger logger, ThreadContext contextHolder)
ClusterStateObserver(ClusterService clusterService, TimeValue timeout, org.apache.logging.log4j.Logger logger, ThreadContext contextHolder)
ClusterStateObserver(ClusterState initialState, ClusterService clusterService, TimeValue timeout, org.apache.logging.log4j.Logger logger, ThreadContext contextHolder)

Method Summary

Modifier and Type	Method and Description
boolean	isTimedOut() indicates whether this observer has timedout
ClusterState	setAndGetObservedState() sets the last observed state to the currently applied cluster state and returns it
void	waitForNextChange(ClusterStateObserver.Listener listener)
void	waitForNextChange(ClusterStateObserver.Listener listener, java.util.function.Predicate<ClusterState> statePredicate)
void	waitForNextChange(ClusterStateObserver.Listener listener, java.util.function.Predicate<ClusterState> statePredicate, TimeValue timeOutValue) Wait for the next cluster state which satisfies statePredicate
void	waitForNextChange(ClusterStateObserver.Listener listener, TimeValue timeOutValue)

Methods inherited from class java.lang.Object

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

Field Detail

logger

protected final org.apache.logging.log4j.Logger logger

Constructor Detail

ClusterStateObserver

public ClusterStateObserver(ClusterService clusterService,
                            org.apache.logging.log4j.Logger logger,
                            ThreadContext contextHolder)

ClusterStateObserver

public ClusterStateObserver(ClusterService clusterService,
                            @Nullable
                            TimeValue timeout,
                            org.apache.logging.log4j.Logger logger,
                            ThreadContext contextHolder)

Parameters:

timeout - a global timeout for this observer. After it has expired the observer will fail any existing or new #waitForNextChange calls. Set to null to wait indefinitely

ClusterStateObserver

public ClusterStateObserver(ClusterState initialState,
                            ClusterService clusterService,
                            @Nullable
                            TimeValue timeout,
                            org.apache.logging.log4j.Logger logger,
                            ThreadContext contextHolder)

Parameters:

timeout - a global timeout for this observer. After it has expired the observer will fail any existing or new #waitForNextChange calls. Set to null to wait indefinitely

Method Detail

setAndGetObservedState

public ClusterState setAndGetObservedState()

sets the last observed state to the currently applied cluster state and returns it

isTimedOut

public boolean isTimedOut()

indicates whether this observer has timedout

waitForNextChange

public void waitForNextChange(ClusterStateObserver.Listener listener)

waitForNextChange

public void waitForNextChange(ClusterStateObserver.Listener listener,
                              @Nullable
                              TimeValue timeOutValue)

waitForNextChange

public void waitForNextChange(ClusterStateObserver.Listener listener,
                              java.util.function.Predicate<ClusterState> statePredicate)

waitForNextChange

public void waitForNextChange(ClusterStateObserver.Listener listener,
                              java.util.function.Predicate<ClusterState> statePredicate,
                              @Nullable
                              TimeValue timeOutValue)

Wait for the next cluster state which satisfies statePredicate

Parameters:

listener - callback listener

statePredicate - predicate to check whether cluster state changes are relevant and the callback should be called

timeOutValue - a timeout for waiting. If null the global observer timeout will be used.