The ATG platform implements a session backup facility that allows you to specify a set of session-scoped or window-scoped Nucleus components and properties that should be backed up after every request. This session backup mechanism saves these components and properties, and restores them when the application server migrates a session to another server.

To enable ATG’s backup, set the backingUpSessions property to true in the /atg/dynamo/Configuration.properties file in the localconfig layer.

backingUpSessions=true

By default, the user’s profile and shopping cart (if one exists) are backed up. To back up additional session-scoped components, set the sessionBackupServerPropertyList property in the /atg/dynamo/Configuration.properties file to a comma-separated list of Nucleus component properties.

Keep in mind when backing up additional information that the more you back up, the more data the app server must save, which could affect performance.

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.