The Redlock algorithm suggested for use with Redis has been the subject of some of criticism:

https://martin.kleppmann.com/2016/02/08/how-to-do-distribute...

Kleppman is the author of Designing Data-Intensive Applications and generally someone whose opinion I trust in such things.

I love Redis and use it extensively at $dayjob, but I stick to Consul for managing distributed locks. Consul was built from the ground up to handle such things; Redis handles it as a bit more of an afterthought / consequence of other features.

True, not a native feature of Redis. I'll put Consul on my list of things to check, thanks for contributing to my knowledge.

Regarding the article, I realized I used the lock for efficiency and not correctness, and it might be why I never encountered issues.

Antirez claims it is. Others are far more critical of his claims.

Personally I'd strongly suggest using a proper consensus implementation such as etcd, consul, zk.

If implemented correctly, there are guarantees of safety and liveness: https://redis.io/topics/distlock

No, it relies on time.

You should use Zookeeper, etcd or Consul