[HyperDB] multi-datacenter configuration

[Andy Skelton]

> does this mean there is a single point of failure then?
> if the data center with the master (write) db is inaccessible/down/whatever
> or that db server is down/offline/whatever then no writes can happen?

Yes.

We do not use multi-master anywhere in our system, so I don't know
from experience, but I think if you use that you will be able to
configure HyperDB to work with it.

Andy