org.apache.flink.runtime.leaderelection

Class ZooKeeperLeaderElectionDriver

java.lang.Object

org.apache.flink.runtime.leaderelection.ZooKeeperLeaderElectionDriver

All Implemented Interfaces:

LeaderElectionDriver, org.apache.flink.shaded.curator4.org.apache.curator.framework.api.UnhandledErrorListener, org.apache.flink.shaded.curator4.org.apache.curator.framework.recipes.cache.NodeCacheListener, org.apache.flink.shaded.curator4.org.apache.curator.framework.recipes.leader.LeaderLatchListener

public class ZooKeeperLeaderElectionDriver
extends Object
implements LeaderElectionDriver, org.apache.flink.shaded.curator4.org.apache.curator.framework.recipes.leader.LeaderLatchListener, org.apache.flink.shaded.curator4.org.apache.curator.framework.recipes.cache.NodeCacheListener, org.apache.flink.shaded.curator4.org.apache.curator.framework.api.UnhandledErrorListener

LeaderElectionDriver implementation for Zookeeper. The leading JobManager is elected using ZooKeeper. The current leader's address as well as its leader session ID is published via ZooKeeper.

Constructor Summary

Constructors

Constructor and Description
ZooKeeperLeaderElectionDriver(org.apache.flink.shaded.curator4.org.apache.curator.framework.CuratorFramework client, String latchPath, String leaderPath, LeaderElectionEventHandler leaderElectionEventHandler, FatalErrorHandler fatalErrorHandler, String leaderContenderDescription) Creates a ZooKeeperLeaderElectionDriver object.

Method Summary

Modifier and Type	Method and Description
void	close() Close the services used for leader election.
boolean	hasLeadership() Check whether the driver still have the leadership in the distributed coordination system.
void	isLeader()
void	nodeChanged()
void	notLeader()
String	toString()
void	unhandledError(String message, Throwable e)
void	writeLeaderInformation(LeaderInformation leaderInformation) Writes the current leader's address as well the given leader session ID to ZooKeeper.

Methods inherited from class java.lang.Object

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

Constructor Detail

ZooKeeperLeaderElectionDriver

public ZooKeeperLeaderElectionDriver(org.apache.flink.shaded.curator4.org.apache.curator.framework.CuratorFramework client,
                                     String latchPath,
                                     String leaderPath,
                                     LeaderElectionEventHandler leaderElectionEventHandler,
                                     FatalErrorHandler fatalErrorHandler,
                                     String leaderContenderDescription)
                              throws Exception

Creates a ZooKeeperLeaderElectionDriver object.

Parameters:

client - Client which is connected to the ZooKeeper quorum

latchPath - ZooKeeper node path for the leader election latch

leaderPath - ZooKeeper node path for the node which stores the current leader information

leaderElectionEventHandler - Event handler for processing leader change events

fatalErrorHandler - Fatal error handler

leaderContenderDescription - Leader contender description

Throws:

Exception

Method Detail

close

public void close()
           throws Exception

Description copied from interface: LeaderElectionDriver

Close the services used for leader election.

Specified by:

close in interface LeaderElectionDriver

Throws:

Exception

hasLeadership

public boolean hasLeadership()

Description copied from interface: LeaderElectionDriver

Check whether the driver still have the leadership in the distributed coordination system.

Specified by:

hasLeadership in interface LeaderElectionDriver

Returns:

Return whether the driver has leadership.

isLeader

public void isLeader()

Specified by:

isLeader in interface org.apache.flink.shaded.curator4.org.apache.curator.framework.recipes.leader.LeaderLatchListener

notLeader

public void notLeader()

Specified by:

notLeader in interface org.apache.flink.shaded.curator4.org.apache.curator.framework.recipes.leader.LeaderLatchListener

nodeChanged

public void nodeChanged()
                 throws Exception

Specified by:

nodeChanged in interface org.apache.flink.shaded.curator4.org.apache.curator.framework.recipes.cache.NodeCacheListener

Throws:

Exception

writeLeaderInformation

public void writeLeaderInformation(LeaderInformation leaderInformation)

Writes the current leader's address as well the given leader session ID to ZooKeeper.

Specified by:

writeLeaderInformation in interface LeaderElectionDriver

Parameters:

leaderInformation - current leader information. It could be LeaderInformation.empty(), which means the caller want to clear the leader information on external storage. Please remember that the clear operation should only happen before a new leader is elected and has written his leader information on the storage. Otherwise, we may have a risk to wrongly update the storage with empty leader information.

unhandledError

public void unhandledError(String message,
                           Throwable e)

Specified by:

unhandledError in interface org.apache.flink.shaded.curator4.org.apache.curator.framework.api.UnhandledErrorListener

toString

public String toString()

Overrides:

toString in class Object