In short, either the storage layer provides enough guarantees to ensure safety without redlock OR it is not possible to ensure safety.

I believe that antirez's proposal is the former, but if he has a safe algorithm that does not require a linearizable CAS operation in the storage layer and is safe w/ redlock, I would love to hear it.

I also provided an example of how to use Cassandra which is eventually consistent safely with a locking service that provides monotonic tokens.