PersistentManagerBase (Apache Tomcat 8.0.15 API Documentation)

java.lang.Object
- org.apache.catalina.util.LifecycleBase
- - org.apache.catalina.util.LifecycleMBeanBase
  - - org.apache.catalina.session.ManagerBase
    - - org.apache.catalina.session.PersistentManagerBase

All Implemented Interfaces:

PropertyChangeListener, EventListener, MBeanRegistration, DistributedManager, JmxEnabled, Lifecycle, Manager, StoreManager

Direct Known Subclasses:

PersistentManager
```
public abstract class PersistentManagerBase
extends ManagerBase
implements StoreManager
```
Extends the ManagerBase class to implement most of the functionality required by a Manager which supports any kind of persistence, even if only for restarts.
IMPLEMENTATION NOTE: Correct behavior of session storing and reloading depends upon external calls to the start() and stop() methods of this class at the correct times.

Author:

Craig R. McClanahan

Nested Class Summary
- Nested classes/interfaces inherited from class org.apache.catalina.session.ManagerBase
  ManagerBase.SessionTiming

Field Summary

Fields
Modifier and Type	Field and Description
`protected int`	`maxIdleBackup` How long a session must be idle before it should be backed up
`protected int`	`maxIdleSwap` The maximum time a session may be idle before it should be swapped to file just on general principle.
`protected int`	`minIdleSwap` Minimum time a session must be idle before it is swapped to disk.
`protected boolean`	`saveOnRestart` Whether to save and reload sessions when the Manager `unload` and `load` methods are called.
`protected Store`	`store` Store object which will manage the Session store.

Fields inherited from class org.apache.catalina.session.ManagerBase
distributable, duplicates, expiredSessions, maxActive, maxActiveSessions, maxInactiveInterval, processExpiresFrequency, processingTime, rejectedSessions, secureRandomAlgorithm, secureRandomClass, secureRandomProvider, SESSION_ID_LENGTH_UNSET, sessionCounter, sessionCreationTiming, sessionExpirationTiming, sessionIdGenerator, sessionIdGeneratorClass, sessionIdLength, sessionMaxAliveTime, sessions, sm, support, TIMING_STATS_CACHE_SIZE

Fields inherited from class org.apache.catalina.util.LifecycleMBeanBase
mserver

Fields inherited from interface org.apache.catalina.Lifecycle
AFTER_DESTROY_EVENT, AFTER_INIT_EVENT, AFTER_START_EVENT, AFTER_STOP_EVENT, BEFORE_DESTROY_EVENT, BEFORE_INIT_EVENT, BEFORE_START_EVENT, BEFORE_STOP_EVENT, CONFIGURE_START_EVENT, CONFIGURE_STOP_EVENT, PERIODIC_EVENT, START_EVENT, STOP_EVENT

Constructor Summary

Constructors
Constructor and Description

PersistentManagerBase()

Constructors
Constructor and Description
`PersistentManagerBase()`

Method Summary

Methods
Modifier and Type	Method and Description
`void`	`clearStore()` Clear all sessions from the Store.
`Session`	`findSession(String id)` Return the active Session, associated with this Manager, with the specified session id (if any); otherwise return `null`.
`int`	`getActiveSessionsFull()` Returns the total session count for primary, backup and proxy.
`int`	`getMaxIdleBackup()` Indicates how many seconds old a session can get, after its last use in a request, before it should be backed up to the store. -1 means sessions are not backed up.
`int`	`getMaxIdleSwap()` The time in seconds after which a session should be swapped out of memory to disk.
`int`	`getMinIdleSwap()` The minimum time in seconds that a session must be idle before it can be swapped out of memory, or -1 if it can be swapped out at any time.
`String`	`getName()` Return the descriptive short name of this Manager implementation.
`boolean`	`getSaveOnRestart()` Indicates whether sessions are saved when the Manager is shut down properly.
`Set<String>`	`getSessionIdsFull()` Returns the list of all sessions IDS (primary, backup and proxy).
`Store`	`getStore()` Return the Store object which manages persistent Session storage for this Manager.
`boolean`	`isLoaded(String id)` Return true, if the session id is loaded in memory otherwise false is returned
`void`	`load()` Load all sessions found in the persistence mechanism, assuming they are marked as valid and have not passed their expiration limit.
`void`	`processExpires()` Implements the Manager interface, direct call to processExpires and processPersistenceChecks
`protected void`	`processMaxActiveSwaps()` Swap idle sessions out to Store if too many are active
`protected void`	`processMaxIdleBackups()` Back up idle sessions.
`protected void`	`processMaxIdleSwaps()` Swap idle sessions out to Store if they are idle too long.
`void`	`processPersistenceChecks()` Called by the background thread after active sessions have been checked for expiration, to allow sessions to be swapped out, backed up, etc.
`void`	`remove(Session session, boolean update)` Remove this Session from the active Sessions for this Manager, and from the Store.
`protected void`	`removeSession(String id)` Remove this Session from the active Sessions for this Manager, and from the Store.
`void`	`removeSuper(Session session)` Remove this Session from the active Sessions for this Manager, but not from the Store.
`void`	`setMaxIdleBackup(int backup)` Sets the option to back sessions up to the Store after they are used in a request.
`void`	`setMaxIdleSwap(int max)` Sets the time in seconds after which a session should be swapped out of memory to disk.
`void`	`setMinIdleSwap(int min)` Sets the minimum time in seconds that a session must be idle before it can be swapped out of memory due to maxActiveSession.
`void`	`setSaveOnRestart(boolean saveOnRestart)` Set the option to save sessions to the Store when the Manager is shut down, then loaded when the Manager starts again.
`void`	`setStore(Store store)` Set the Store object which will manage persistent Session storage for this Manager.
`protected void`	`startInternal()` Start this component and implement the requirements of `LifecycleBase.startInternal()`.
`protected void`	`stopInternal()` Stop this component and implement the requirements of `LifecycleBase.stopInternal()`.
`protected Session`	`swapIn(String id)` Look for a session in the Store and, if found, restore it in the Manager's list of active sessions if appropriate.
`protected void`	`swapOut(Session session)` Remove the session from the Manager's list of active sessions and write it out to the Store.
`void`	`unload()` Save all currently active sessions in the appropriate persistence mechanism, if any.
`protected void`	`writeSession(Session session)` Write the provided session to the Store without modifying the copy in memory or triggering passivation events.

Methods inherited from class org.apache.catalina.session.ManagerBase
add, addPropertyChangeListener, backgroundProcess, changeSessionId, changeSessionId, changeSessionId, createEmptySession, createSession, expireSession, findSessions, generateSessionId, getActiveSessions, getClassName, getContainer, getContext, getCreationTime, getCreationTimestamp, getDistributable, getDomainInternal, getDuplicates, getEngine, getExpiredSessions, getJvmRoute, getLastAccessedTime, getLastAccessedTimestamp, getMaxActive, getMaxActiveSessions, getMaxInactiveInterval, getNewSession, getObjectNameKeyProperties, getProcessExpiresFrequency, getProcessingTime, getRejectedSessions, getSecureRandomAlgorithm, getSecureRandomClass, getSecureRandomProvider, getSession, getSessionAttribute, getSessionAverageAliveTime, getSessionCounter, getSessionCreateRate, getSessionExpireRate, getSessionIdGenerator, getSessionIdLength, getSessionMaxAliveTime, getThisAccessedTime, getThisAccessedTimestamp, initInternal, listSessionIds, propertyChange, remove, removePropertyChangeListener, setContainer, setContext, setDistributable, setDuplicates, setExpiredSessions, setMaxActive, setMaxActiveSessions, setMaxInactiveInterval, setProcessExpiresFrequency, setProcessingTime, setSecureRandomAlgorithm, setSecureRandomClass, setSecureRandomProvider, setSessionCounter, setSessionIdGenerator, setSessionIdLength, setSessionMaxAliveTime, toString, updateSessionMaxAliveTime

Methods inherited from class org.apache.catalina.util.LifecycleMBeanBase
destroyInternal, getDomain, getObjectName, postDeregister, postRegister, preDeregister, preRegister, register, setDomain, unregister

Methods inherited from class org.apache.catalina.util.LifecycleBase
addLifecycleListener, destroy, findLifecycleListeners, fireLifecycleEvent, getState, getStateName, init, removeLifecycleListener, setState, setState, start, stop

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Field Detail
  - store
```
protected Store store
```
    Store object which will manage the Session store.
  - saveOnRestart
```
protected boolean saveOnRestart
```
    Whether to save and reload sessions when the Manager unload and load methods are called.
  - maxIdleBackup
```
protected int maxIdleBackup
```
    How long a session must be idle before it should be backed up. -1 means sessions won't be backed up.
  - minIdleSwap
```
protected int minIdleSwap
```
    Minimum time a session must be idle before it is swapped to disk. This overrides maxActiveSessions, to prevent thrashing if there are lots of active sessions. Setting to -1 means it's ignored.
  - maxIdleSwap
```
protected int maxIdleSwap
```
    The maximum time a session may be idle before it should be swapped to file just on general principle. Setting this to -1 means sessions should not be forced out.
- Constructor Detail
  - PersistentManagerBase
```
public PersistentManagerBase()
```
- Method Detail
  - getMaxIdleBackup
```
public int getMaxIdleBackup()
```
    Indicates how many seconds old a session can get, after its last use in a request, before it should be backed up to the store. -1 means sessions are not backed up.
  - setMaxIdleBackup
```
public void setMaxIdleBackup(int backup)
```
    Sets the option to back sessions up to the Store after they are used in a request. Sessions remain available in memory after being backed up, so they are not passivated as they are when swapped out. The value set indicates how old a session may get (since its last use) before it must be backed up: -1 means sessions are not backed up.
    Note that this is not a hard limit: sessions are checked against this age limit periodically according to processExpiresFrequency. This value should be considered to indicate when a session is ripe for backing up.
    So it is possible that a session may be idle for maxIdleBackup + processExpiresFrequency * engine.backgroundProcessorDelay seconds, plus the time it takes to handle other session expiration, swapping, etc. tasks.
    
    Parameters:
    backup - The number of seconds after their last accessed time when they should be written to the Store.
  - getMaxIdleSwap
```
public int getMaxIdleSwap()
```
    The time in seconds after which a session should be swapped out of memory to disk.
  - setMaxIdleSwap
```
public void setMaxIdleSwap(int max)
```
    Sets the time in seconds after which a session should be swapped out of memory to disk.
  - getMinIdleSwap
```
public int getMinIdleSwap()
```
    The minimum time in seconds that a session must be idle before it can be swapped out of memory, or -1 if it can be swapped out at any time.
  - setMinIdleSwap
```
public void setMinIdleSwap(int min)
```
    Sets the minimum time in seconds that a session must be idle before it can be swapped out of memory due to maxActiveSession. Set it to -1 if it can be swapped out at any time.
  - isLoaded
```
public boolean isLoaded(String id)
```
    Return true, if the session id is loaded in memory otherwise false is returned
    
    Parameters:
    id - The session id for the session to be searched for
  - getName
```
public String getName()
```
    Return the descriptive short name of this Manager implementation.
    
    Overrides:
    
    getName in class ManagerBase
  - setStore
```
public void setStore(Store store)
```
    Set the Store object which will manage persistent Session storage for this Manager.
    
    Parameters:
    store - the associated Store
  - getStore
```
public Store getStore()
```
    Return the Store object which manages persistent Session storage for this Manager.
    
    Specified by:
    
    getStore in interface StoreManager
  - getSaveOnRestart
```
public boolean getSaveOnRestart()
```
    Indicates whether sessions are saved when the Manager is shut down properly. This requires the unload() method to be called.
  - setSaveOnRestart
```
public void setSaveOnRestart(boolean saveOnRestart)
```
    Set the option to save sessions to the Store when the Manager is shut down, then loaded when the Manager starts again. If set to false, any sessions found in the Store may still be picked up when the Manager is started again.
    
    Parameters:
    saveOnRestart - true if sessions should be saved on restart, false if they should be ignored.
  - clearStore
```
public void clearStore()
```
    Clear all sessions from the Store.
  - processExpires
```
public void processExpires()
```
    Implements the Manager interface, direct call to processExpires and processPersistenceChecks
    
    Overrides:
    
    processExpires in class ManagerBase
  - processPersistenceChecks
```
public void processPersistenceChecks()
```
    Called by the background thread after active sessions have been checked for expiration, to allow sessions to be swapped out, backed up, etc.
  - findSession
```
public Session findSession(String id)
                    throws IOException
```
    Return the active Session, associated with this Manager, with the specified session id (if any); otherwise return null. This method checks the persistence store if persistence is enabled, otherwise just uses the functionality from ManagerBase.
    
    Specified by:
    
    findSession in interface Manager
    
    Overrides:
    
    findSession in class ManagerBase
    
    Parameters:
    id - The session id for the session to be returned
    
    Throws:
    
    IllegalStateException - if a new session cannot be instantiated for any reason
    
    IOException - if an input/output error occurs while processing this request
  - removeSuper
```
public void removeSuper(Session session)
```
    Remove this Session from the active Sessions for this Manager, but not from the Store. (Used by the PersistentValve)
    
    Specified by:
    
    removeSuper in interface StoreManager
    
    Parameters:
    session - Session to be removed
  - load
```
public void load()
```
    Load all sessions found in the persistence mechanism, assuming they are marked as valid and have not passed their expiration limit. If persistence is not supported, this method returns without doing anything.
    Note that by default, this method is not called by the MiddleManager class. In order to use it, a subclass must specifically call it, for example in the start() and/or processPersistenceChecks() methods.
    
    Specified by:
    
    load in interface Manager
  - remove
```
public void remove(Session session,
          boolean update)
```
    Remove this Session from the active Sessions for this Manager, and from the Store.
    
    Specified by:
    
    remove in interface Manager
    
    Overrides:
    
    remove in class ManagerBase
    
    Parameters:
    session - Session to be removed
    update - Should the expiration statistics be updated
  - removeSession
```
protected void removeSession(String id)
```
    Remove this Session from the active Sessions for this Manager, and from the Store.
    
    Parameters:
    id - Session's id to be removed
  - unload
```
public void unload()
```
    Save all currently active sessions in the appropriate persistence mechanism, if any. If persistence is not supported, this method returns without doing anything.
    Note that by default, this method is not called by the MiddleManager class. In order to use it, a subclass must specifically call it, for example in the stop() and/or processPersistenceChecks() methods.
    
    Specified by:
    
    unload in interface Manager
  - getActiveSessionsFull
```
public int getActiveSessionsFull()
```
    Description copied from interface: DistributedManager
    
    Returns the total session count for primary, backup and proxy.
    
    Specified by:
    
    getActiveSessionsFull in interface DistributedManager
    
    Returns:
    The total session count across the cluster.
  - getSessionIdsFull
```
public Set<String> getSessionIdsFull()
```
    Description copied from interface: DistributedManager
    
    Returns the list of all sessions IDS (primary, backup and proxy).
    
    Specified by:
    
    getSessionIdsFull in interface DistributedManager
    
    Returns:
    The complete set of sessions IDs across the cluster.
  - swapIn
```
protected Session swapIn(String id)
                  throws IOException
```
    Look for a session in the Store and, if found, restore it in the Manager's list of active sessions if appropriate. The session will be removed from the Store after swapping in, but will not be added to the active session list if it is invalid or past its expiration.
    
    Throws:
    
    IOException
  - swapOut
```
protected void swapOut(Session session)
                throws IOException
```
    Remove the session from the Manager's list of active sessions and write it out to the Store. If the session is past its expiration or invalid, this method does nothing.
    
    Parameters:
    session - The Session to write out.
    
    Throws:
    
    IOException
  - writeSession
```
protected void writeSession(Session session)
                     throws IOException
```
    Write the provided session to the Store without modifying the copy in memory or triggering passivation events. Does nothing if the session is invalid or past its expiration.
    
    Throws:
    
    IOException
  - startInternal
```
protected void startInternal()
                      throws LifecycleException
```
    Start this component and implement the requirements of LifecycleBase.startInternal().
    
    Overrides:
    
    startInternal in class ManagerBase
    
    Throws:
    
    LifecycleException - if this component detects a fatal error that prevents this component from being used
  - stopInternal
```
protected void stopInternal()
                     throws LifecycleException
```
    Stop this component and implement the requirements of LifecycleBase.stopInternal().
    
    Overrides:
    
    stopInternal in class ManagerBase
    
    Throws:
    
    LifecycleException - if this component detects a fatal error that prevents this component from being used
  - processMaxIdleSwaps
```
protected void processMaxIdleSwaps()
```
    Swap idle sessions out to Store if they are idle too long.
  - processMaxActiveSwaps
```
protected void processMaxActiveSwaps()
```
    Swap idle sessions out to Store if too many are active
  - processMaxIdleBackups
```
protected void processMaxIdleBackups()
```
    Back up idle sessions.

Class PersistentManagerBase

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.catalina.session.ManagerBase

Field Summary

Fields inherited from class org.apache.catalina.session.ManagerBase

Fields inherited from class org.apache.catalina.util.LifecycleMBeanBase

Fields inherited from interface org.apache.catalina.Lifecycle

Constructor Summary

Method Summary

Methods inherited from class org.apache.catalina.session.ManagerBase

Methods inherited from class org.apache.catalina.util.LifecycleMBeanBase

Methods inherited from class org.apache.catalina.util.LifecycleBase

Methods inherited from class java.lang.Object

Field Detail

store

saveOnRestart

maxIdleBackup

minIdleSwap

maxIdleSwap

Constructor Detail

PersistentManagerBase

Method Detail

getMaxIdleBackup

setMaxIdleBackup

getMaxIdleSwap

setMaxIdleSwap

getMinIdleSwap

setMinIdleSwap

isLoaded

getName

setStore

getStore

getSaveOnRestart

setSaveOnRestart

clearStore

processExpires

processPersistenceChecks

findSession

removeSuper

load

remove

removeSession

unload

getActiveSessionsFull

getSessionIdsFull

swapIn

swapOut

writeSession

startInternal

stopInternal

processMaxIdleSwaps

processMaxActiveSwaps

processMaxIdleBackups