Package org.apache.zookeeper.server

Interface SessionTracker

All Known Implementing Classes:

LeaderSessionTracker, LearnerSessionTracker, LocalSessionTracker, SessionTrackerImpl, UpgradeableSessionTracker

public interface SessionTracker

This is the basic interface that ZooKeeperServer uses to track sessions. The standalone and leader ZooKeeperServer use the same SessionTracker. The FollowerZooKeeperServer uses a SessionTracker which is basically a simple shell to track information to be forwarded to the leader.

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static interface	SessionTracker.Session
static interface	SessionTracker.SessionExpirer

Method Summary

Modifier and Type	Method	Description
void	checkGlobalSession(long sessionId, Object owner)	Strictly check that a given session is a global session or not
void	checkSession(long sessionId, Object owner)	Checks whether the SessionTracker is aware of this session, the session is still active, and the owner matches.
boolean	commitSession(long id, int to)	Add the session to the local session map or global one in zkDB.
long	createSession(int sessionTimeout)
void	dumpSessions(PrintWriter pwriter)	Text dump of session information, suitable for debugging.
long	getLocalSessionCount()	If this session tracker supports local sessions, return how many.
Map<Long,Set<Long>>	getSessionExpiryMap()	Returns a mapping of time to session IDs that expire at that time.
Set<Long>	globalSessions()	Get a set of global session IDs
boolean	isLocalSessionsEnabled()
boolean	isTrackingSession(long sessionId)
Set<Long>	localSessions()	Get a set of local session IDs
void	removeSession(long sessionId)
void	setOwner(long id, Object owner)
void	setSessionClosing(long sessionId)	Mark that the session is in the process of closing.
void	shutdown()
boolean	touchSession(long sessionId, int sessionTimeout)
boolean	trackSession(long id, int to)	Track the session expire, not add to ZkDb.

Method Detail

createSession

long createSession(int sessionTimeout)

trackSession

boolean trackSession(long id,
                     int to)

Track the session expire, not add to ZkDb.

Parameters:

id - sessionId

to - sessionTimeout

Returns:

whether the session was newly tracked (if false, already tracked)

commitSession

boolean commitSession(long id,
                      int to)

Add the session to the local session map or global one in zkDB.

Parameters:

id - sessionId

to - sessionTimeout

Returns:

whether the session was newly added (if false, already existed)

touchSession

boolean touchSession(long sessionId,
                     int sessionTimeout)

Parameters:

sessionId -

sessionTimeout -

Returns:

false if session is no longer active

setSessionClosing

void setSessionClosing(long sessionId)

Mark that the session is in the process of closing.

Parameters:

sessionId -

shutdown

void shutdown()

removeSession

void removeSession(long sessionId)

Parameters:

sessionId -

isTrackingSession

boolean isTrackingSession(long sessionId)

Parameters:

sessionId -

Returns:

whether or not the SessionTracker is aware of this session

checkSession

void checkSession(long sessionId,
                  Object owner)
           throws KeeperException.SessionExpiredException,
                  KeeperException.SessionMovedException,
                  KeeperException.UnknownSessionException

Checks whether the SessionTracker is aware of this session, the session is still active, and the owner matches. If the owner wasn't previously set, this sets the owner of the session. UnknownSessionException should never been thrown to the client. It is only used internally to deal with possible local session from other machine

Parameters:

sessionId -

owner -

Throws:

KeeperException.SessionExpiredException

KeeperException.SessionMovedException

KeeperException.UnknownSessionException

checkGlobalSession

void checkGlobalSession(long sessionId,
                        Object owner)
                 throws KeeperException.SessionExpiredException,
                        KeeperException.SessionMovedException

Strictly check that a given session is a global session or not

Parameters:

sessionId -

owner -

Throws:

KeeperException.SessionExpiredException

KeeperException.SessionMovedException

setOwner

void setOwner(long id,
              Object owner)
       throws KeeperException.SessionExpiredException

Throws:

KeeperException.SessionExpiredException

dumpSessions

void dumpSessions(PrintWriter pwriter)

Text dump of session information, suitable for debugging.

Parameters:

pwriter - the output writer

getSessionExpiryMap

Map<Long,Set<Long>> getSessionExpiryMap()

Returns a mapping of time to session IDs that expire at that time.

getLocalSessionCount

long getLocalSessionCount()

If this session tracker supports local sessions, return how many. otherwise returns 0;

isLocalSessionsEnabled

boolean isLocalSessionsEnabled()

globalSessions

Set<Long> globalSessions()

Get a set of global session IDs

localSessions

Set<Long> localSessions()

Get a set of local session IDs