org.apache.flink.runtime.leaderretrieval

Class ZooKeeperLeaderRetrievalService

java.lang.Object

org.apache.flink.runtime.leaderretrieval.ZooKeeperLeaderRetrievalService

All Implemented Interfaces:

org.apache.curator.framework.recipes.cache.NodeCacheListener, LeaderRetrievalService

public class ZooKeeperLeaderRetrievalService
extends Object
implements LeaderRetrievalService, org.apache.curator.framework.recipes.cache.NodeCacheListener

The counterpart to the ZooKeeperLeaderElectionService. This implementation of the LeaderRetrievalService retrieves the current leader which has been elected by the ZooKeeperLeaderElectionService. The leader address as well as the current leader session ID is retrieved from ZooKeeper.

Constructor Summary

Constructors

Constructor and Description
ZooKeeperLeaderRetrievalService(org.apache.curator.framework.CuratorFramework client, String retrievalPath) Creates a leader retrieval service which uses ZooKeeper to retrieve the leader information.

Method Summary

Modifier and Type	Method and Description
protected void	handleStateChange(org.apache.curator.framework.state.ConnectionState newState)
void	nodeChanged()
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

ZooKeeperLeaderRetrievalService

public ZooKeeperLeaderRetrievalService(org.apache.curator.framework.CuratorFramework client,
                                       String retrievalPath)

Creates a leader retrieval service which uses ZooKeeper to retrieve the leader information.

Parameters:

client - Client which constitutes the connection to the ZooKeeper quorum

retrievalPath - Path of the ZooKeeper node which contains the leader information

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

nodeChanged

public void nodeChanged()
                 throws Exception

Specified by:

nodeChanged in interface org.apache.curator.framework.recipes.cache.NodeCacheListener

Throws:

Exception

handleStateChange

protected void handleStateChange(org.apache.curator.framework.state.ConnectionState newState)