The Manager Component

The Manager element represents the session manager that will be used to create and maintain HTTP sessions as requested by the associated web application.

A Manager element MAY be nested inside a Context component. If it is not included, a default Manager configuration will be created automatically, which is sufficient for most requirements.

Common Attributes

All implementations of Manager support the following attributes: Attribute Description className Java class name of the implementation to use. This class must implement the org.apache.catalina.Manager interface. If not specified, the standard value (defined below) will be used. distributable Set to true to ask the session manager to enforce the restrictions described in the Servlet Specification on distributable applications (primarily, this would mean that all session attributes must implement java.io.Serializable). Set to false (the default) to not enforce these restrictions. NOTE - The value for this property is inherited automatically based on the presence or absence of the <distributable> element in the web application deployment descriptor (/WEB-INF/web.xml). maxInactiveInterval The default maximum inactive interval (in minutes) for Sessions created by this Manager. If not specified, the default value is sixty (60) minutes. NOTE - The value for this property is inherited automatically if you specify a <session-timeout> element in the web application deployment descriptor (/WEB-INF/web.xml).

Standard Implementation

The standard implementation of Manager is org.apache.catalina.session.StandardManager. It supports the following additional attributes (in addition to the common attributes listed above): Attribute Description algorithm Name of the Message Digest algorithm used to calculate session identifiers produced by this Manager. This value must be supported by the java.security.MessageDigest class. If not specified, the default value is "MD5". checkInterval The number of seconds between checks for expired sessions for this manager. The default value is 60 seconds. debug The level of debugging detail logged by this Engine to the associated Logger. Higher numbers generate more detailed output. If not specified, the default debugging detail level is zero (0). entropy A String value that is utilized when seeding the random number generator used to create session identifiers for this Manager. If not specified, a semi-useful value is calculated, but a long String value should be specified in security-conscious environments. maxActiveSessions The maximum number of active sessions that will be created by this Manager, or -1 (the default) for no limit. pathname Absolute or relative (to the work directory for this Context) pathname of the file in which session state will be preserved across application restarts, if possible. The default is "SESSIONS.ser". See Restart Persistence for more information. randomClass Java class name of the java.util.Random implementation class to use. If not specified, the default value is java.security.SecureRandom.

No components may be nested inside a Manager element.

Restart Persistence

Whenver Catalina is shut down normally and restarted, or when an application reload is triggered, the standard Manager implementation will attempt to serialize all currently active sessions to a disk file located via the pathname attribute. All such saved sessions will then be deserialized and activated (assuming they have not expired in the mean time) when the application reload is completed. In order to successfully restore the state of session attributes, all such attributes MUST implement the java.io.Serializable interface. You MAY cause the Manager to enforce this restriction by including the <distributable> element in your web application deployment descriptor (/WEB-INF/web.xml).