Re: 3.7 Arbiter and/or quorum

[Scott Harvanek <scott.harvanek@xxxxxxxxx>]

Using the virt group which does-

cluster.quorum-type: auto
cluster.server-quorum-type: server

And from my understanding this means that quorum enforcement is enabled, and that it's brick related so if I only have two bricks then I cannot achieve 51% and split brain is likely even with a third node in the pool.  If I move to fixed 1, then the likelihood of splitbrain is high.

So what do I do here, get a fourth node and do distributed replicated?  Trying to find the best performance option while minimizing split brain potential and I'm stuck with 3.6 clients ( RHEV-H ) so the aforementioned arbiter is out, Replica 3 just seems to be a pig on the client side due to the triple write.

--
Scott H.

Ravishankar N

July 15, 2015 at 1:09 PM

On 07/15/2015 09:22 PM, Scott Harvanek wrote:

I saw Ravi mention something earlier about the new arbiter volumes in 3.7

- Can you run a arbiter 3.7 server volume with 3.6 clients?  Or does this not work?

Unfortunately, no. This is because the logic for the feature is mostly in the AFR translator which is loaded on the client process (with some minor logic in the arbiter translator loaded on the brick process). So both clients and servers need to be 3.7.

Quorum question -

- 3.6 server and clients, replica 2, however there's three+ servers in the cluster ( gluster pool list ).  If one of the replicas fail is quorum maintained via the other servers in the cluster even though they are not part of the volume?

That would depend on what type of quorum is enabled (client or server side). Each type has a different impact. You can look for the meaning of cluster.quorum-type, cluster.quorum-count (these are client side quorum options, applicable only to replicate volumes) and cluster.server-quorum-type, cluster.server-quorum-ratio (these are server side quorum options; they are not specific to replicate volumes) in 'gluster volume set help`.

HTH,
Ravi

Scott Harvanek

July 15, 2015 at 11:52 AM

I saw Ravi mention something earlier about the new arbiter volumes in 3.7

- Can you run a arbiter 3.7 server volume with 3.6 clients?  Or does this not work?


Quorum question -

- 3.6 server and clients, replica 2, however there's three+ servers in the cluster ( gluster pool list ).  If one of the replicas fail is quorum maintained via the other servers in the cluster even though they are not part of the volume?

_______________________________________________
Gluster-users mailing list
Gluster-users@xxxxxxxxxxx
http://www.gluster.org/mailman/listinfo/gluster-users