Aside from the Raspberry Pi being cool, what would this buy you over AWS, a server running some VMs, or some old spare boxes? Getting some experience with load-balanced systems isn't necessarily a bad idea, but the Pi doesn't seem like the best hardware for the job.
Assuming you do want to do this, consider getting one more capable box, and using it as a firewall, load balancer, NFS server and database server. Your Pis can then talk to this machine and do the webby things. (If you want to avoid a single point of failure, use CARP/VRRP, some sensible load balancer, DRBD and database replication. Reboot all Pis on failover, failing over NFS mounts is very painful.)
Comments
Aside from the Raspberry Pi being cool, what would this buy you over AWS, a server running some VMs, or some old spare boxes? Getting some experience with load-balanced systems isn't necessarily a bad idea, but the Pi doesn't seem like the best hardware for the job.
Assuming you do want to do this, consider getting one more capable box, and using it as a firewall, load balancer, NFS server and database server. Your Pis can then talk to this machine and do the webby things. (If you want to avoid a single point of failure, use CARP/VRRP, some sensible load balancer, DRBD and database replication. Reboot all Pis on failover, failing over NFS mounts is very painful.)