But you need to know if you can do that something first, or if you've done that something too many times in the last N minutes (and could get blocked, forcing t

But you need to know if you can do that something first, or if you've done that something too many times in the last N minutes (and could get blocked, forcing thousands of other somethings to get endlessly queued). Or if that something could take too long, and actually you could be doing 200 other somethings in the same time etc. It's not that simple.