I've been reading up on replication algorithms. If
you are interested in playing with model checking
or understanding Paxos or Raft (really, it is not that difficult),
I put a short getting started guide, along with a Paxos
promela/Spin model that you can check in 2 seconds, here:
Personally I've tried TLA+ but I've never actually had it
complete after hours of running. It was nice to discover
that Spin can check models (okay, they are single round
not multiple round models, but still) much more quickly.
Enjoy,
Jason