[OpenAFS] Folder Update Delays

Russ Allbery rra@stanford.edu
Tue, 10 Jan 2012 09:56:40 -0800

Bobb Crosbie <bobb.crosbie@cremeglobal.com> writes:

> We have users who regularly use the AFS filespace to
> collaborate. Sharing folders and documents.  However, there are often
> long delays in one user seeing the additions/updates/modifications to
> folders and documents made by another user.

> We have showed the users how to flush the Directory/Volume, and that
> generally sorts things out, however it's not really the ideal solution
> as the users are not that technical, plus they need to actually know
> that there has been updates to the hierarchy so that they know to do the
> flush.

> Should this be happening So much ?  It seems to occur quite regularly and
> can take a while for the updated view to appear.

This generally means that you're losing callbacks, which leads me to
immediately bs suspicious of firewalls or NAT.  Since AFS is UDP-based,
the client can think that it has a "connection" with the server for the
callback channel, but either the NAT mapping or the firewall rule may have
timed out.  Then the server can't send callback breaks to the client to
tell them that something has changed in a directory, but the client is
none the wiser.

We poke holes in our firewalls for our AFS servers to allow through all
the UDP traffic without regard to UDP session state so that having UDP
session tables timeout never cuts off callbacks.

Russ Allbery (rra@stanford.edu)             <http://www.eyrie.org/~eagle/>