Manager

An instance of the org.apache.catalina.Manager interface is responsible for managing the sessions for a given context.

As shown in the previous image, the main responsibilities of a Manager include creating and managing the session instances for its context.

It is specified using the<Manager> element in server.xml, which has attributes such as the maximum inactive interval, also known as the session's timeout, and the session identifier length. These attributes are used as defaults for the sessions created by this manager.

Its load() and unload() methods support the persistence of sessions to secondary storage. These methods do nothing when persistence is not supported by a given Manager implementation.

Its backgroundProcess() method is called on a periodic basis by its context to allow it to do housekeeping chores such as harvesting expired sessions.

Implementations of this interface, such as the StandardManager and PersistentManager classes in the org.apache.catalina.session...