[OpenAFS] DB servers seperate from fileservers

John Hascall john@iastate.edu
Tue, 08 Aug 2006 15:00:33 CDT

> On Tuesday, August 08, 2006 02:49:41 PM -0400 Derek Atkins 
> <warlord@MIT.EDU> wrote:
> > Ken Hornstein <kenh@cmf.nrl.navy.mil> writes:
> > I wonder if we could add a cache manager query so that apps could
> > ask the cache manager for server stats?  Obviously this would be
> > an optional query, and the app should continue to use the current
> > random choice if there is no cache manager.  But I think it would
> > help this case if there were some way to store this kind of state
> > on a client.

> You mean like VIOCCKSERV, which tells you which servers the cache manager 
> currently thinks are down?  Or more like VIOCGETSPREFS, which tells you 
> what preference order the cache manager has assigned to servers?

   Don't those deal with fileservers?
   And isn't the case at hand dealing with DB servers?

   Seems to me that a far simplier method would be for stand-alone
   clients to start with a short timeout and circle through the
   DB servers quicker.

   To wit, something like this, in pseudo-code:

        for (i = 4; i <= 4096; i <<= 1) {
           for (j = 0; j < n_DBservers; ++j) {
              rc = connect_to_server_with_timeout_in_msecs(server[j], i);
              if (rc == SUCCESS) break;
        if (rc != SUCCESS) die_a_horrible_death();