Queue#run fires a processStalledJobs loop when concurrency is 0

[xdc0]

I noticed this with my use case, where the concurrency value is set through an environment variable, this way you can have a service running on many instances with configurable concurrency values on each of them. A simple way to prevent a worker from processing jobs is by setting concurrency to 0 when it's needed.

However, setting the concurrency value to 0 by calling queue.process(0, myJobHandler) has the side effect of always running a processStalledJobs loop, this means that a worker that is not intended to run any jobs will run jobs through the processStalledJobs loop, as a side note, processStalledJobs currently has a flaw where it also processes fresh jobs, not only stalled ones.

[xdc0]

While I can argue that calling Queue#process with 0 concurrency is an anti-pattern, it should have tighter constraints, either explicitly throw when setting concurrency as a non positive integer value, or return early when concurrency <= 0 so it doesn't do any process at all.

[manast]

can you provide more information regarding the issue in processStalledJobswhere it also processes fresh jobs?

[bradvogel]

It's the issue described here: #257. So processStalledJobs is actually processing quite a few fresh jobs.

[bradvogel]

Fixed in #359

[doublerebel]

Looks like #359 was merged so this can be closed?