The Directory Server Connector persistently stores the changenumber of the last retro changelog entry that it has processed. When the connector begins detecting changes again, it can process all changes that occurred when it was not running, by starting with the last changenumber that it processed. This changenumber is stored in the connector's persist directory, for example, /var/opt/SUNWisw/persist/ADP100/accessor.state. If this file does not exist, then the connector will detect only new changes in Directory Server.
This way of processing the changes has an effect on the failover process. If synchronization is never started for the failover installation, then the file will not exist, and the Directory Server Connector will only detect new changes. Changes that occurred during the failover process are lost. However, initializing the accessor.state file presents its own problems. If synchronization is started immediately after installation to produce the accessor.state file, and then stopped, when synchronization is started after failing over, the Directory Server Connector will try to process all Retro changelog entries. To strike a balance between these two options, the Retro changelog Plugin on the failover installation's preferred master (master3-eu.gt.com) is configured to only store changes for one day (this limit is increased during the failover process). Once synchronization is started for the failover installation, the Directory Server Connector only processes one day's worth of changes in the directory server.
The Sun Java System Directory Server Administration Guide contains instructions on how to enable trimming of the retro changelog. Essentially, the nsslapd-changelogmaxage attribute on the cn=Retro Changelog Plugin, cn=plugins,cn=config entry is modified and Directory Server is restarted. Setting this value to 1d trims entries that are older than one day. The value can be modified from the command line using ldapmodify or by directly editing the Directory Server's dse.ldif file while Directory Server is not running.