Package org.apache.solr.cluster.events.impl

Class CollectionsRepairEventListener

java.lang.Object

org.apache.solr.cluster.events.impl.CollectionsRepairEventListener

All Implemented Interfaces:

Closeable, AutoCloseable, ClusterSingleton, ClusterEventListener

public class CollectionsRepairEventListener
extends Object
implements ClusterEventListener, ClusterSingleton, Closeable

This is an illustration how to re-implement the combination of Solr 8x NodeLostTrigger and AutoAddReplicasPlanAction to maintain the collection's replicas when nodes are lost.

The notion of waitFor delay between detection and repair action is implemented as a scheduled execution of the repair method, which is called every 1 sec to check whether there are any lost nodes that exceeded their waitFor period.

NOTE: this functionality would be probably more reliable when executed also as a periodically scheduled check - both as a reactive (listener) and proactive (scheduled) measure.

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.solr.cloud.ClusterSingleton

ClusterSingleton.State

Field Summary

Fields

Modifier and Type	Field	Description
static int	DEFAULT_WAIT_FOR_SEC
static String	PLUGIN_NAME

Constructor Summary

Constructors

Constructor	Description
CollectionsRepairEventListener(CoreContainer cc)

Method Summary

Modifier and Type	Method	Description
void	close()
String	getName()	Unique name of this singleton.
ClusterSingleton.State	getState()	Returns the current state of the component.
void	onEvent(ClusterEvent event)	Handle the event.
void	setWaitForSecond(int waitForSecond)
void	start()	Start the operation of the component.
void	stop()	Stop the operation of the component.

Methods inherited from class java.lang.Object

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

Field Detail

PLUGIN_NAME

public static final String PLUGIN_NAME

See Also:

Constant Field Values

DEFAULT_WAIT_FOR_SEC

public static final int DEFAULT_WAIT_FOR_SEC

See Also:

Constant Field Values

Constructor Detail

CollectionsRepairEventListener

public CollectionsRepairEventListener(CoreContainer cc)

Method Detail

setWaitForSecond

public void setWaitForSecond(int waitForSecond)

getName

public String getName()

Description copied from interface: ClusterSingleton

Unique name of this singleton. Used for registration.

Specified by:

getName in interface ClusterSingleton

onEvent

public void onEvent(ClusterEvent event)

Description copied from interface: ClusterEventListener

Handle the event. Implementations should be non-blocking - if any long processing is needed it should be performed asynchronously.

Specified by:

onEvent in interface ClusterEventListener

Parameters:

event - cluster event

start

public void start()
           throws Exception

Description copied from interface: ClusterSingleton

Start the operation of the component. Initially this method should set the state to STARTING, and on success it should set the state to RUNNING.

Specified by:

start in interface ClusterSingleton

Throws:

Exception - on startup errors. The component should revert to the STOPPED state.

getState

public ClusterSingleton.State getState()

Description copied from interface: ClusterSingleton

Returns the current state of the component.

Specified by:

getState in interface ClusterSingleton

stop

public void stop()

Description copied from interface: ClusterSingleton

Stop the operation of the component. Initially this method should set the state to STOPPING, and on return it should set the state to STOPPED. Components should also avoid holding any resource when in STOPPED state.

Specified by:

stop in interface ClusterSingleton

close

public void close()
           throws IOException

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Throws:

IOException