PUBLISHER (see Who) modifies the meta-data on a given server,
the other servers update there own copies later using the centralised
USER (see Who) queries for a file that no server provides in their own cache,
the first requested server provides an HTML form
in order to recall the
USER latter, when the file becomes available.
- DATE (see Who) is implement by the Cron (see Cron) daemon.
- By reading the “message of the day”, the
is asked to do some maintenance operations such as:
- to provide external supports needed for extraction
or needed to perform a periodic check.
- to backup files available from the cache on new supports
and to share them with the related collection.