Package org.apache.zookeeper.server.quorum

Class FollowerZooKeeperServer

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.FollowerZooKeeperServer

All Implemented Interfaces:

ServerStats.Provider, SessionTracker.SessionExpirer

public class FollowerZooKeeperServer
extends LearnerZooKeeperServer

Just like the standard ZooKeeperServer. We just replace the request processors: FollowerRequestProcessor -> CommitProcessor -> FinalRequestProcessor A SyncRequestProcessor is also spawned off to log proposals from the leader.

Nested Class Summary

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

ZooKeeperServer.MissingSessionException, ZooKeeperServer.State

Field Summary

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

commitProcessor, syncProcessor

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

self, upgradeableSessionTracker

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

ALLOW_SASL_FAILED_CLIENTS, CLOSE_SESSION_TXN_ENABLED, DEFAULT_STARTING_BUFFER_SIZE, DEFAULT_THROTTLED_OP_WAIT_TIME, DEFAULT_TICK_TIME, ENABLE_EAGER_ACL_CHECK, ENFORCE_QUOTA, enforceQuota, firstProcessor, GET_CHILDREN_RESPONSE_CACHE_SIZE, GET_DATA_RESPONSE_CACHE_SIZE, GLOBAL_OUTSTANDING_LIMIT, initialConfig, INT_BUFFER_STARTING_SIZE_BYTES, intBufferStartingSizeBytes, jmxDataTreeBean, jmxServerBean, jvmPauseMonitor, listenBacklog, maxSessionTimeout, minSessionTimeout, ok, reconfigEnabled, SASL_SUPER_USER, secureServerCnxnFactory, serverCnxnFactory, sessionTracker, SKIP_ACL, SNAP_COUNT, state, throttledOpWaitTime, tickTime, ZOOKEEPER_DIGEST_ENABLED, ZOOKEEPER_SERIALIZE_LAST_PROCESSED_ZXID_ENABLED

Method Summary

Modifier and Type	Method	Description
Request	appendRequest(TxnHeader hdr, Record txn, TxnDigest digest)	Build a request for the txn and append it to the transaction log
void	commit(long zxid)	When a COMMIT message is received, eventually this method is called, which matches up the zxid from the COMMIT with (hopefully) the head of the pendingTxns queue and hands it to the commitProcessor to commit.
Follower	getFollower()
int	getGlobalOutstandingLimit()
Learner	getLearner()	Abstract method to return the learner associated with this server.
String	getState()
void	logRequest(TxnHeader hdr, Record txn, TxnDigest digest)
protected void	registerMetrics()
protected void	setupRequestProcessors()
void	sync()
protected void	unregisterMetrics()

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

createSessionTracker, getServerId, getTouchSnapshot, registerJMX, registerJMX, revalidateSession, shutdown, unregisterJMX, unregisterJMX

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

checkUpgradeSession, dumpConf, dumpMonitorValues, setLocalSessionFlag, setState, startSessionTracker, upgrade

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

authWriteRequest, canShutdown, checkACL, checkPasswd, checkQuota, checkRequestSizeWhenReceivingMessage, closeSession, closeSession, connThrottle, createRequestThrottler, decInProcess, dumpEphemerals, enqueueRequest, expire, expire, finishSessionInit, getClientPort, getClientPortListenBacklog, getConf, getConnectionDropChance, getDataDirSize, getEphemerals, getGetChildrenResponseCache, getInflight, getInitialConfig, getInProcess, getLargeRequestBytes, getLargeRequestMaxBytes, getLargeRequestThreshold, getLastProcessedZxid, getLogDirSize, getMaxClientCnxnsPerHost, getMaxSessionTimeout, getMinSessionTimeout, getNumAliveConnections, getOutstandingHandshakeNum, getOutstandingRequests, getReadResponseCache, getRequestPathMetricsCollector, getSecureClientPort, getSecureServerCnxnFactory, getServerCnxnFactory, getSessionExpiryMap, getSessionTracker, getSnapCount, getSnapSizeInBytes, getThrottledOpWaitTime, getTickTime, getTxnLogElapsedSyncTime, getTxnLogFactory, getZKDatabase, getZkShutdownHandler, getZooKeeperServerListener, getZxid, incInProcess, isCloseSessionTxnEnabled, isDigestEnabled, isEnableEagerACLCheck, isReconfigEnabled, isResponseCachingEnabled, isRunning, isSerializeLastProcessedZxidEnabled, killSession, loadData, processConnectRequest, processPacket, processTxn, processTxn, reopenSession, requestFinished, restoreFromSnapshot, serverStats, setClientPortListenBacklog, setCloseSessionTxnEnabled, setCreateSessionTrackerServerId, setDigestEnabled, setEnableEagerACLCheck, setLargeRequestMaxBytes, setLargeRequestThreshold, setMaxSessionTimeout, setMinSessionTimeout, setOwner, setResponseCachingEnabled, setSecureServerCnxnFactory, setSerializeLastProcessedZxidEnabled, setServerCnxnFactory, setThrottledOpWaitTime, setTickTime, setTxnLogFactory, setZKDatabase, setZxid, shouldForceWriteInitialSnapshotAfterLeaderElection, shouldThrottle, shutdown, startdata, startJvmPauseMonitor, startRequestThrottler, startServing, startup, startupWithoutServing, submitRequest, submitRequestNow, takeSnapshot, takeSnapshot, takeSnapshot, truncateLog, validateSession

Methods inherited from class java.lang.Object

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

Method Detail

getFollower

public Follower getFollower()

setupRequestProcessors

protected void setupRequestProcessors()

Overrides:

setupRequestProcessors in class ZooKeeperServer

logRequest

public void logRequest(TxnHeader hdr,
                       Record txn,
                       TxnDigest digest)

appendRequest

public Request appendRequest(TxnHeader hdr,
                             Record txn,
                             TxnDigest digest)
                      throws IOException

Build a request for the txn and append it to the transaction log

Parameters:

hdr - the txn header

txn - the txn

digest - the digest of txn

Returns:

a request moving through a chain of RequestProcessors

Throws:

IOException

commit

public void commit(long zxid)

When a COMMIT message is received, eventually this method is called, which matches up the zxid from the COMMIT with (hopefully) the head of the pendingTxns queue and hands it to the commitProcessor to commit.

Parameters:

zxid - - must correspond to the head of pendingTxns if it exists

sync

public void sync()

getGlobalOutstandingLimit

public int getGlobalOutstandingLimit()

Overrides:

getGlobalOutstandingLimit in class ZooKeeperServer

getState

public String getState()

Specified by:

getState in interface ServerStats.Provider

Overrides:

getState in class ZooKeeperServer

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

registerMetrics

protected void registerMetrics()

Overrides:

registerMetrics in class QuorumZooKeeperServer

unregisterMetrics

protected void unregisterMetrics()

Overrides:

unregisterMetrics in class QuorumZooKeeperServer