Package org.apache.bookkeeper.replication

Class AuditorElector

java.lang.Object

org.apache.bookkeeper.replication.AuditorElector

@StatsDoc(name="auditor",
          help="Auditor related stats")
public class AuditorElector
extends Object

Performing auditor election using Apache ZooKeeper. Using ZooKeeper as a coordination service, when a bookie bids for auditor, it creates an ephemeral sequential file (znode) on ZooKeeper and considered as their vote. Vote format is 'V_sequencenumber'. Election will be done by comparing the ephemeral sequential numbers and the bookie which has created the least znode will be elected as Auditor. All the other bookies will be watching on their predecessor znode according to the ephemeral sequence numbers.

Field Summary

Fields

Modifier and Type	Field	Description
(package private) Auditor	auditor
(package private) Runnable	shutdownTask

Constructor Summary

Constructors

Constructor	Description
AuditorElector(String bookieId, ServerConfiguration conf)
AuditorElector(String bookieId, ServerConfiguration conf, BookKeeper bkc, boolean ownBkc)	AuditorElector for performing the auditor election.
AuditorElector(String bookieId, ServerConfiguration conf, BookKeeper bkc, StatsLogger statsLogger, boolean ownBkc)	AuditorElector for performing the auditor election.

Method Summary

Modifier and Type	Method	Description
(package private) Auditor	getAuditor()
BookieId	getCurrentAuditor()
boolean	isRunning()	If current bookie is running as auditor, return the status of the auditor.
void	shutdown()	Shutting down AuditorElector.
Future<?>	start()
(package private) Future<?>	submitElectionTask()	Performing the auditor election using the ZooKeeper ephemeral sequential znode.
String	toString()

Methods inherited from class java.lang.Object

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

Field Details

auditor

Auditor auditor

shutdownTask

Runnable shutdownTask

Constructor Details

AuditorElector

public AuditorElector(String bookieId,
 ServerConfiguration conf)
               throws ReplicationException.UnavailableException

Throws:

ReplicationException.UnavailableException

AuditorElector

public AuditorElector(String bookieId,
 ServerConfiguration conf,
 BookKeeper bkc,
 boolean ownBkc)
               throws ReplicationException.UnavailableException

AuditorElector for performing the auditor election.

Parameters:

bookieId - - bookie identifier, comprises HostAddress:Port

conf - - configuration

bkc - - bookkeeper instance

Throws:

ReplicationException.UnavailableException - throws unavailable exception while initializing the elector

AuditorElector

public AuditorElector(String bookieId,
 ServerConfiguration conf,
 BookKeeper bkc,
 StatsLogger statsLogger,
 boolean ownBkc)
               throws ReplicationException.UnavailableException

AuditorElector for performing the auditor election.

Parameters:

bookieId - - bookie identifier, comprises HostAddress:Port

conf - - configuration

bkc - - bookkeeper instance

statsLogger - - stats logger

Throws:

ReplicationException.UnavailableException - throws unavailable exception while initializing the elector

Method Details

start

public Future<?> start()

submitElectionTask

Future<?> submitElectionTask()

Performing the auditor election using the ZooKeeper ephemeral sequential znode. The bookie which has created the least sequential will be elect as Auditor.

getAuditor

Auditor getAuditor()

getCurrentAuditor

public BookieId getCurrentAuditor()
                           throws IOException,
InterruptedException

Throws:

IOException

InterruptedException

shutdown

public void shutdown()
              throws InterruptedException

Shutting down AuditorElector.

Throws:

InterruptedException

isRunning

public boolean isRunning()

If current bookie is running as auditor, return the status of the auditor. Otherwise return the status of elector.

Returns:

toString

public String toString()

Overrides:

toString in class Object