org.apache.storm.zookeeper

Class LeaderElectorImp

java.lang.Object

org.apache.storm.zookeeper.LeaderElectorImp

All Implemented Interfaces:

Closeable, AutoCloseable, ILeaderElector

public class LeaderElectorImp
extends Object
implements ILeaderElector

Constructor Summary

Constructors

Constructor and Description
LeaderElectorImp(Map conf, List<String> servers, org.apache.curator.framework.CuratorFramework zk, String leaderlockPath, String id, AtomicReference<org.apache.curator.framework.recipes.leader.LeaderLatch> leaderLatch, AtomicReference<org.apache.curator.framework.recipes.leader.LeaderLatchListener> leaderLatchListener, BlobStore blobStore)

Method Summary

Modifier and Type	Method and Description
void	addToLeaderLockQueue() queue up for leadership lock.
void	close() Method called to allow for cleanup.
List<NimbusInfo>	getAllNimbuses()
NimbusInfo	getLeader()
boolean	isLeader()
void	prepare(Map conf) Method guaranteed to be called as part of initialization of leader elector instance.
void	removeFromLeaderLockQueue() Removes the caller from the leader lock queue.

Methods inherited from class java.lang.Object

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

Constructor Detail

LeaderElectorImp

public LeaderElectorImp(Map conf,
                        List<String> servers,
                        org.apache.curator.framework.CuratorFramework zk,
                        String leaderlockPath,
                        String id,
                        AtomicReference<org.apache.curator.framework.recipes.leader.LeaderLatch> leaderLatch,
                        AtomicReference<org.apache.curator.framework.recipes.leader.LeaderLatchListener> leaderLatchListener,
                        BlobStore blobStore)

Method Detail

prepare

public void prepare(Map conf)

Description copied from interface: ILeaderElector

Method guaranteed to be called as part of initialization of leader elector instance.

Specified by:

prepare in interface ILeaderElector

Parameters:

conf - configuration

addToLeaderLockQueue

public void addToLeaderLockQueue()
                          throws Exception

Description copied from interface: ILeaderElector

queue up for leadership lock. The call returns immediately and the caller must check isLeader() to perform any leadership action. This method can be called multiple times so it needs to be idempotent.

Specified by:

addToLeaderLockQueue in interface ILeaderElector

Throws:

Exception

removeFromLeaderLockQueue

public void removeFromLeaderLockQueue()
                               throws Exception

Description copied from interface: ILeaderElector

Removes the caller from the leader lock queue. If the caller is leader also releases the lock. This method can be called multiple times so it needs to be idempotent.

Specified by:

removeFromLeaderLockQueue in interface ILeaderElector

Throws:

Exception

isLeader

public boolean isLeader()
                 throws Exception

Specified by:

isLeader in interface ILeaderElector

Returns:

true if the caller currently has the leader lock.

Throws:

Exception

getLeader

public NimbusInfo getLeader()

Specified by:

getLeader in interface ILeaderElector

Returns:

the current leader’s address , may return null if no one has the lock.

getAllNimbuses

public List<NimbusInfo> getAllNimbuses()
                                throws Exception

Specified by:

getAllNimbuses in interface ILeaderElector

Returns:

list of current nimbus addresses, includes leader.

Throws:

Exception

close

public void close()

Description copied from interface: ILeaderElector

Method called to allow for cleanup. once close this object can not be reused.

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Specified by:

close in interface ILeaderElector