Puma 6.2.1 warns about threads started in app boot

[victorfgs]

Hi there,

Ever since the 5.x.x release, Puma detects and warns threads that are started in app boot (before the forking process) as you can see here. I am currently seeing the judoscale gem as one of those threads in my app(I think the thread that reports web metrics are instantiated once in the Runner process when running in cluster mode?)

It seems to me that this thread should be marked as fork safe as it was on rails connection pooling since Puma should not be worried about it.

Is my analysis correct? Is there something that I can help to fix this warning?

[adamlogic]

I think you're right that we can mark the thread as fork-safe, since we'll detect if the PID changes and start a separate reporter thread for each fork.

judoscale-ruby/judoscale-ruby/lib/judoscale/reporter.rb

Lines 66 to 68 in 3c30f60

	def started?
	@pid == Process.pid
	end

I swear we've had this discussion before, but I can't find any history of it. 🤔