[Pacemaker] One Cluster or Two

[Andrew Beekhof]

On Fri, Dec 7, 2012 at 9:59 AM, Art Zemon <art at hens-teeth.net> wrote:
> Folks,
>
> I am building a high availability web hosting platform which will
> include a pair of web servers with an OCFS2 shared filesystem and a
> MySQL database server with a backup (using a DRBD-based filesystem
> instead of MySQL replication). Does this sound like one cluster or two
> (one for the web servers and a second for the database servers)?

Its really a personal preference.
I like clusters with >2 nodes because quorum makes sense.
And it allows for more flexibility in your failover preferences - for
instance you might allow the web server to use the db spare as a last
resort.

>
> If one cluster, each configuration is very very simple.
>
> If two clusters, the config is more complex because it has everything in
> it for all resources, plus location constraints. But it can have a real
> quorum since the full cluster will be at least four nodes.
>
> Thoughts?
>
> Thanks,
>     -- Art Z.
>
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