Package org.apache.zookeeper.server.quorum

Class ObserverZooKeeperServer

java.lang.Object

org.apache.zookeeper.server.ZooKeeperServer

org.apache.zookeeper.server.quorum.QuorumZooKeeperServer

org.apache.zookeeper.server.quorum.LearnerZooKeeperServer

org.apache.zookeeper.server.quorum.ObserverZooKeeperServer

All Implemented Interfaces:

ServerStats.Provider, SessionTracker.SessionExpirer

public class ObserverZooKeeperServer
extends LearnerZooKeeperServer

A ZooKeeperServer for the Observer node type. Not much is different, but we anticipate specializing the request processors in the future.

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.zookeeper.server.ZooKeeperServer

ZooKeeperServer.BasicDataTreeBuilder, ZooKeeperServer.DataTreeBuilder, ZooKeeperServer.MissingSessionException, ZooKeeperServer.State

Field Summary

Fields inherited from class org.apache.zookeeper.server.quorum.QuorumZooKeeperServer

self

Fields inherited from class org.apache.zookeeper.server.ZooKeeperServer

DEFAULT_TICK_TIME, firstProcessor, jmxDataTreeBean, jmxServerBean, maxSessionTimeout, minSessionTimeout, ok, sessionTracker, state, tickTime

Method Summary

Modifier and Type	Method	Description
void	commitRequest(Request request)	Unlike a Follower, which sees a full request only during the PROPOSAL phase, Observers get all the data required with the INFORM packet.
Learner	getLearner()	Abstract method to return the learner associated with this server.
Observer	getObserver()
java.lang.String	getState()
protected void	setupRequestProcessors()	Set up the request processors for an Observer: firstProcesor->commitProcessor->finalProcessor
void	shutdown()
void	sync()

Methods inherited from class org.apache.zookeeper.server.quorum.LearnerZooKeeperServer

createSessionTracker, getServerId, getTouchSnapshot, registerJMX, registerJMX, revalidateSession, startSessionTracker, unregisterJMX, unregisterJMX

Methods inherited from class org.apache.zookeeper.server.quorum.QuorumZooKeeperServer

dumpConf, setState

Methods inherited from class org.apache.zookeeper.server.ZooKeeperServer

canShutdown, checkPasswd, closeSession, closeSession, decInProcess, dumpEphemerals, expire, finishSessionInit, getClientPort, getGlobalOutstandingLimit, getInProcess, getLastProcessedZxid, getMaxSessionTimeout, getMinSessionTimeout, getNumAliveConnections, getOutstandingRequests, getServerCnxnFactory, getSnapCount, getTickTime, getTxnLogFactory, getZKDatabase, getZooKeeperServerListener, getZxid, incInProcess, isRunning, killSession, loadData, processConnectRequest, processPacket, processTxn, reopenSession, serverStats, setMaxSessionTimeout, setMinSessionTimeout, setOwner, setServerCnxnFactory, setTickTime, setTxnLogFactory, setZKDatabase, setZxid, shouldThrottle, shutdown, startdata, startup, submitRequest, takeSnapshot, truncateLog

Methods inherited from class java.lang.Object

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

Method Detail

getObserver

public Observer getObserver()

getLearner

public Learner getLearner()

Description copied from class: LearnerZooKeeperServer

Abstract method to return the learner associated with this server. Since the Learner may change under our feet (when QuorumPeer reassigns it) we can't simply take a reference here. Instead, we need the subclasses to implement this.

Specified by:

getLearner in class LearnerZooKeeperServer

commitRequest

public void commitRequest(Request request)

Unlike a Follower, which sees a full request only during the PROPOSAL phase, Observers get all the data required with the INFORM packet. This method commits a request that has been unpacked by from an INFORM received from the Leader.

Parameters:

request -

setupRequestProcessors

protected void setupRequestProcessors()

Set up the request processors for an Observer: firstProcesor->commitProcessor->finalProcessor

Overrides:

setupRequestProcessors in class ZooKeeperServer

sync

public void sync()

getState

public java.lang.String getState()

Specified by:

getState in interface ServerStats.Provider

Overrides:

getState in class ZooKeeperServer

shutdown

public void shutdown()

Overrides:

shutdown in class ZooKeeperServer