[Gluster-users] 3.7 Arbiter and/or quorum

[Scott Harvanek]

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 <mailto:ravishankar at redhat.com>
> 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 <mailto:scott.harvanek at login.com>
> 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?
>

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.gluster.org/pipermail/gluster-users/attachments/20150715/915c8975/attachment.html>