The ATG platform implements a session backup facility that allows you to specify a set of session-scoped Nucleus components and properties that should be backed up after every request. This session backup mechanism saves these session-scoped components and properties, and restores them when the application server migrates a session to another server.
ATG’s session backup works with your application server’s persistence facility. To use session backup, you must be running your application server in a cluster, and you must enable its in-memory replication form of session persistence for each ATG application (see your application server documentation for information). Note that when you enable in-memory replication for an application, that application must not be deployed on any application server that is not part of a cluster.
To enable ATG’s session backup, set the backingUpSessions property to true in the /atg/dynamo/Configuration.properties file in the standard localconfig layer (that is, not a server-specific localconfig).
By default, the user’s profile and shopping cart (if one exists) are backed up. To back up additional components, set the sessionBackupServerPropertyList property in the /atg/dynamo/Configuration.properties file to a comma-separated list of Nucleus component properties. For example:
backingUpSessions=true
sessionBackupServerPropertyList+=\
/atg/userprofiling/ProfileFailService.uidForFailover,\
/atg/dynamo/security/UserFailService.savedPersonae
Each component or property specified in sessionBackupServerPropertyList must implement java.io.Serializable (or Externalizable). If a component is listed without any properties, the entire component is backed up.
