Mysql Slave Databases, Load Balancing AND Failover

[Make Money?]

Here's what I'm trying to do:

I want to use Vbulletin's slave database option AND have failover. I've got 2 servers. I'm using www.zoneedit.com to round-robin my dns between Server A and Server B. Both Servers Vbulletin's are writing to the database on Server A and reading from the database on Server B.

In the event Server A fails, Server B needs to suddenly now both read and write to it's own (hopefully up-to-date) replicated database. Is there any way to tell Server B it needs to now stand on it's own 2...erm...legs?

Then what happens when Server A recovers and comes back online? While the servers can each be configured to act as both master and slave, Server A may not have caught up before it is thrust back into action. Perhaps there is a way to force Server A not to appear? You can specify a string on a page for Zoneedit to check to see if a server is offline or not. Maybe a script in vbulletin which checks the binlogs of both servers to see if it's caught up before revealling some text?

And maybe this script could even show or not show the string depending on the load of the server, that way Zoneedit would switch the dns long before the actual crash occurs!

Any cool ideas? :banana: