On Tuesday 07 Dec 2010 10:14:38 you wrote:
> I've had very bad experiences with multiple high-traffic drupal sites on a
> single database; it behaves very badly. I can't comment on the other CMSes
> you mention.
Is that a single database or a single MySQL instance? Each domain that we
host has it's own database (and many have more than that!), so the table names
are unique to that DB/CMS install.
> The main thing you're going to be running into, I suspect, is the number of
> writes - you can't scale that short of cross-machine partitioning, be it
> horizontal or vertical. Maybe it's possible to use MMM or MySQL Proxy on
> top of such a setup to give the appearance of a single host again, but I
> imagine there would be complexities.
We have dedicated Load Balancers to spread the traffic across multiple MySQL
instances, hence the thinking behind multi-master replication - or have I mis-
understood your point? :)
> We have since shifted to heavy-duty machines running separate Xen VMs for
> every site. Just beginnin with that, but hopes are that will give us the
> independence we need to keep an overloaded site from pulling all the others
> down with it.
Hmmm, that's an interesting concept, I'll have a think about whether that's a
possible solution here as well (although I don't much fancy running 24000 Xen