Data storage and multiple service provider instances for failover

Hi,

I am investigating running two instances of the same SAML SP on two Tomcat nodes for load-balancing and failover purposes.

Does your implementation store data only against the session or does it store data in other locations?

I need to figure out whether configuring session replication between the two Tomcat nodes is sufficient or whether there are other data storage locations that I need to worry about.

Thanks.