If set to true, retains web sessions, stateful session bean instances, and persistently created EJB timers across redeployments. The --keepstate option of the redeploy(1) subcommand takes precedence. The default for both is false.
Some changes to an application between redeployments prevent this feature from working properly. For example, do not change the set of instance variables in the SFSB bean class.
For web applications, this feature is applicable only if in the glassfish-web-app.xml file the persistence-type attribute of the session-manager element is file.
For stateful session bean instances, the persistence type without high availability is set in the server (the sfsb-persistence-type attribute) and must be set to file, which is the default and recommended value.
If any active web session, SFSB instance, or EJB timer fails to be preserved or restored, none of these will be available when the redeployment is complete. However, the redeployment continues and a warning is logged.
To preserve active state data, GlassFish Server serializes the data and saves it in memory. To restore the data, the class loader of the newly redeployed application deserializes the data that was previously saved.
none - contains data