[Gluster-devel] Splitbrain Resolution

[Gordan Bobic]

Samuel Douglas wrote:

>>  I'm not sure that it is that big a drawback. Using HA or RHCS to fail over
>> the IP resources sounds like a pretty standard way to implement fail-over.
>> The major drawback is lack of explicit load-balancing, but having said that,
>> if you mount by hostname you'd still get round-robin DNS load balancing,
>> which is probably good enough.
> 
> When AFR is loaded on the client and AFR subvolumes go offline, any
> open files on the AFR volume are not affected -- the failover is
> transparent. This is not the case with those other 'failover'
> approaches. As I said, it depends on your use case and that could be
> an acceptable tradeoff. If you load AFR on the server, and that server
> goes offline, any clients with files open to it will get a "Transport
> endpoint not connected" or some similar error, and they will have to
> reopen the files etc.

OK - would it be possible to AFR mount 2 servers, which are in turn AFR 
connected to each other (and others)? Would this lead to data corruption 
and/or replication loops that would send everything into meltdown?

>>  Hmm... Now if writes could happen over multicast, that would be pretty
>> cool, as the writes wouldn't scale inversely. But I'm guessing this isn't
>> anywhere on the feature list (yet)...
> 
> Perhaps. I don't think it would be that easy, or nice to implement though.

It would solve a large chunk of the write scalability problem, though.

Gordan