Package org.apache.flink.runtime.leaderretrieval

Class DefaultLeaderRetrievalService

java.lang.Object

org.apache.flink.runtime.leaderretrieval.DefaultLeaderRetrievalService

All Implemented Interfaces:

LeaderRetrievalEventHandler, LeaderRetrievalService

public class DefaultLeaderRetrievalService
extends Object
implements LeaderRetrievalService, LeaderRetrievalEventHandler

The counterpart to the DefaultLeaderElectionService. Composed with different LeaderRetrievalDriver, we could retrieve the leader information from different storage. The leader address as well as the current leader session ID will be retrieved from LeaderRetrievalDriver.

Constructor Summary

Constructors

Constructor	Description
DefaultLeaderRetrievalService(LeaderRetrievalDriverFactory leaderRetrievalDriverFactory)	Creates a default leader retrieval service with specified LeaderRetrievalDriverFactory.

Method Summary

Modifier and Type	Method	Description
void	notifyLeaderAddress(LeaderInformation leaderInformation)	Called by specific LeaderRetrievalDriver to notify leader address.
void	start(LeaderRetrievalListener listener)	Starts the leader retrieval service with the given listener to listen for new leaders.
void	stop()	Stops the leader retrieval service.

Methods inherited from class java.lang.Object

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

Constructor Detail

DefaultLeaderRetrievalService

public DefaultLeaderRetrievalService(LeaderRetrievalDriverFactory leaderRetrievalDriverFactory)

Creates a default leader retrieval service with specified LeaderRetrievalDriverFactory.

Parameters:

leaderRetrievalDriverFactory - LeaderRetrievalDriverFactory used for creating LeaderRetrievalDriver.

Method Detail

start

public void start(LeaderRetrievalListener listener)
           throws Exception

Description copied from interface: LeaderRetrievalService

Starts the leader retrieval service with the given listener to listen for new leaders. This method can only be called once.

Specified by:

start in interface LeaderRetrievalService

Parameters:

listener - The leader retrieval listener which will be notified about new leaders.

Throws:

Exception

stop

public void stop()
          throws Exception

Description copied from interface: LeaderRetrievalService

Stops the leader retrieval service.

Specified by:

stop in interface LeaderRetrievalService

Throws:

Exception

notifyLeaderAddress

public void notifyLeaderAddress(LeaderInformation leaderInformation)

Called by specific LeaderRetrievalDriver to notify leader address.

Specified by:

notifyLeaderAddress in interface LeaderRetrievalEventHandler

Parameters:

leaderInformation - new notified leader information address. The exception will be handled by leader listener.