Is it throughput and latency that are the etcd bottlenecks?
Our database, RonDB, is an in-memory open-source database (a fork of MySQL Cluster). We have scaled it to 100m reads/sec on AWS hardware (not even top of the line). Might be an interesting project to implement an open-source etcd shim on top of it?
Reference: https://www.rondb.com/post/100m-key-lookups-sec-with-rest-ap...