SRV.7.5 Session Timeouts
In the HTTP protocol, there is no explicit termination signal when a client is no
longer active. This means that the only mechanism that can be used to indicate when
a client is no longer active is a timeout period.
The default timeout period for sessions is defined by the servlet container and
can be obtained via the getMaxInactiveInterval method of the HttpSession
interface. This timeout can be changed by the Developer using the
setMaxInactiveInterval method of the HttpSession interface. The timeout
periods used by these methods are defined in seconds. By definition, if the timeout
period for a session is set to -1, the session will never expire.
and from the DTD,
The session-timeout element defines the default session timeout
interval for all sessions created in this web application. The
specified timeout must be expressed in a whole number of minutes.
If the timeout is 0 or less, the container ensures the default
behaviour of sessions is never to time out.
Used in: session-config
<!ELEMENT session-timeout (#PCDATA)>