I think it’s the opposite of what @ashokkarale says. I fact it is core functionality of Queue Trigger.
You just need to allocate appropriate number of robot runtimes (hosts) to machine template associated with the Queue Trigger (1) and set “Maximum number of pending and running jobs allowed simultaneously.” (2)
I suppose this is not possible - Orchestrator will utilise all runtimes associated with particular machine template. So if you have 10 bots but only 2 should process particular queue then only 2 bots should use that machine template.
Exactly. If only 2 out of 10 bots are capable of executing a process you should group them separately using separate machine/machine templates, and linking them to the correct folders etc.
Although This is still a very static approach imho. I always set it as a requirement that all machines need to be able to do any task, and are therefor automatically eachothers backup. I’m aware that software license costs do not always make this economically viable, but that should pretty much be the only reason to not do this. And even then it is better to manage that on a user account level and not on a bot environment level, making it configurable with little effort.