I’ve been working on an erlang port of my php locking daemon in erlang (which is a more appropriate language for this kind of thing.) And I have it all tricked out (ok partially tricked out but hey it’s my first real erlang project and i’ve only spent 2 afternoons on it.)

The api is completely the same between the two (read: simple), and it works great (in my tests.) It supports both exclusive and shared locks, orphaning on disconnect works great for both, stats are working, it’s all running under a supervisor to restart anything that stops, I *think* i’ve done the code well enough that hot code swapping should work as expected. I know there’s a lot of “how an erlang application is packaged” stuff that I don’t know yet.

If i had to describe in a one-liner what this does i would say that lockd is MySQL named locks meets Memcached.

I’m kind of annoyed, however, that “erl -s esuper” doesn’t run the stupid thing, I have to actually run esuper:start(). to get it going. I’ll have to figure that out. You would think that running some precompiled beams/modules/functions/args would be super easy from the outside a-la-init-script, and it probably is but I’m missing something.

Comments on the code are welcome. It’s a pretty cool little thing — my [lack of] mad erlang skills aside.

When I’m ready I’ll be testing it in production, and putting it in a public repo.