Gordan Bobic wrote:
How does the HA translator choose a node, exactly ? Does it randomly
select one from the list of available subvolumes, or does it pick them
in the order they're specified in the config file, or some other way
entirely ?
Not sure what the default is, but you can specify a preferred read
server (writes have to go to all servers regardless) with
"option read-subvolume" in the volume spec.
option read-subvolume is available only in the AFR translator, and if
AFR is being done on server-side (the scenario noted previously in this
thread), then there would be no AFR declaration in the client spec file,
and thus no way to set the read-subvolume option.
The HA translator is not that useful in the context of a straightforward
client-side AFR setup in any case, since (as i understand it) if a given
server dies, the client continues to interact with the remaining defined
servers seamlessly. This, of course, is part of the attraction of
defining AFR on the cleint side ; but in cases where it is not feasible
(overhead concerns, etc...), using HA with server-side AFR is a very
interesting prospect.
Some way to extend simplistic load-balancing features to the HA
translator (or, perhaps, another translator working in concert) would
therefore be quite ideal.
--
Daniel Maher <dma+gluster AT witbe DOT net>
