Other data replication technologies worth looking in to: GlusterFs, Ceph.
Dependent on your db's they should offer replication out of the box.
You can also implement a load balancer, such as HAProxy or Nginx, to distribute incoming network traffic across multiple VMs
If you plan on using this in a production environment, I'd bring in a consultant.
However, I've heard of people in the home-lab sphere use things like heartbeat and drdb. The more nodes the merrier as if you lose connection between the two you'll have a bad time.
Codes strictly on TI-84's
Do you have a link for this?