Introduce "singleton" concept to prevent processing/adding concurrent jobs with same group id

[sneljo1]

Similar to the concept in pg-boss, it makes sense for some use-cases to only allow 1 job within a specific group in an active state and only allow 1 extra to be queued. It would make this library a good fit for my use-case. Is this something that would be possible/makes sense to add here?

https://github.com/timgit/pg-boss/tree/master/docs#sendsingletonname-data-options

[kraih]

I think this feature has come up a few years ago for the Perl version. If i remember correctly we couldn't come up with enough use cases (we usually require at least two unique use cases for a feature to be considered).

[kraih]

Also be aware that locks exist. which makes finding unique use cases without overlap a little harder. https://github.com/mojolicious/minion.js#locks

[sneljo1]

Makes sense, thanks 👍

[sneljo1]

They are definitely versatile, but the only thing with the locks then is that you can really only use it with tasks that have a known/fixed time limit (without overshooting the TTL) and cannot rely on the heartbeats to unlock them automatically. Or is it possible to mimic this heartbeat functionality by somehow extending the lock?