The backend uses dirwatcher to monitor events in the vsys backend directory. For every new script and acl file created, it retrieves the set of users to which the script is to be made available for use. It then invokes operations in the frontend module to actually create the entries. When entries are deleted from the backend directory, the backend instructs the corresponding frontends to delete the pipes corresponding to the entries. The backend also creates the initial vsys tree, and instructs each frontend to populate itself with the set of scripts found at startup time.