Hello! I have a few questions I want to ask about tomcat clustering and i hope this is the right forum to do it in, apolagies if it's not!

I want to be able to set up a tomcat cluster, probably with a Apache load balencer, x amount of tomcat app servers, and y amount of database servers.

Im very new to this so I wanted some clarification. I understand how the load balencing could work, apache running some sort of round-robin allocation of incoming requests to the x tomcat servers, taking 1 out of the cluster if it falls over, i get this and see how it could easily enable succesful horizontal scaling. What I cant work out is how the database back end would be implemented efficently. Say I have something like 1 apache load balencer, 3 tomcat servers, and 1 mysql database server, thats fine, but what if my mysql usage needs to expand over 1 server, would the instances have to be syncronised, or would i just say 'half the tables go to this server and half to that one' and allocate requests accordingly?

I was hoping someone would be able to point me in the right direction regarding this!

Thanks for any help,

Rackham