Question: I've read Lamport's [paper](http://research.microsoft.com/en-us/um/people/lamport/pubs/paxos-simple.pdf) on Paxos. I've also heard that it isn't used much in practice, for reasons of performance. What algorithms are commonly used for consensus in distributed systems?

Answer: 
Not sure if this is helpful (since this is not from actual production information), but in our "distributed systems" course we've studied, along with Paxos, the **Chandra-Toueg** and **Mostefaoui-Raynal** algorithms (of the latter our professor was especially fond).
[Raft](https://raft.github.io/) is more understandable, and faster alternative of Paxos. One of the most popular distributed systems which uses Raft is [Etcd](https://github.com/etcd-io/etcd). Etcd is the distributed store used in Kubernetes. 

It's equivalent to Paxos in fault-tolerance.