Non-clustered, non-persistent, in-memory-only is the default style of session management. In previous versions of Jetty this was referred to as "hash" sessions, as they were stored in a HashMap in memory.

This is delivered by a combination of the DefaultSessionCache (to keep sessions in memory) and a NullSessionDataStore (to avoid session persistence).

If you do nothing, Jetty will instantiate one of each of these objects for each context at startup time using hard-coded defaults.

To explicitly set up non-persisted sessions using modules, use both the session-cache-hash and the session-store-null modules.

Enabling the modules allows you to configure behavior - see the L1 Session Cache for detailed information on configuration options for the DefaultSessionCache. The NullSessionDataStore has no customizable options.