Paxos and viewstamped replication are basically the two most well known other well-known asynchronous consensus mechanisms that have been mathematically verifie

Paxos and viewstamped replication are basically the two most well known other well-known asynchronous consensus mechanisms that have been mathematically verified. If you just need eventual consistency, CRDTs are also possible. Going in the other direction, if you don't mind the latency full consensus with global locking, you could just do that.