[OpenAFS] Re: DB servers "quorum" and OpenAFS tools

Andrew Deason adeason@sinenomine.net
Fri, 24 Jan 2014 11:23:46 -0600

On Fri, 24 Jan 2014 11:41:35 -0500
Jeffrey Hutzelman <jhutz@cmu.edu> wrote:

> The problem is the one-off clients that make _one RPC_ and then exit.
> They have no opportunity to remember what didn't work last time.  It
> might help some for these sorts of clients to use multi, if they're
> doing read-only requests, and probably wouldn't create much load.
> However, for a call that results in a ubik write transaction, I'm not
> entirely sure it's desirable to do a multi call.  That will require some
> additional thought.

At least we could multi call the VOTE_GetSyncSite call, perhaps, in
situations where we actually use GetSyncSite.

> In the meantime, another thing that might be helpful is for clients
> about to make such an RPC to query the CM's record of which servers
> are up, and use that to decide which server to contact.  A quick
> VIOCCKSERV with the fast flag set could make a big difference.

We have some code to implement this and honoring the client server
preferences; finishing it I think just got buried behind higher

Andrew Deason