I've read this thread:

http://silverstripe.org/archive/show/60224#post60224

But it's not exactly describing what I want to do, plus I don't see a huge need to share a single cache from a performance perspective, as our site isn't heavily loaded. I'm more interested in the failover aspect of 2 web servers that share a database. I realize that I'd have two sets of cache in /tmp, and that I'd need to do a ?flush=1 on both app servers, but are there any potential database problems or constraints I should be concerned about? Am I over-simplifying this?