When utilizing multi cores via Node.js' cluster module is it guaranteed that each forked node worker is assigned to a different core?
If it's not guaranteed is there any way to control or manage it and eventually guarantee that all ends up in different cores? Or the OS' scheduler distributes them evenly?
A while ago I did some tests with cluster module which you can check in this post that I wrote. Looking at the system monitor screenshots it is this pretty straightforward to understand what happens under the hood (with and without cluster module).
It is indeed up to the OS to distribute processes over the cores. You could obtain the pid of a child process and use an external utility to set the CPU affinity of that process. That would, of course, not be very portable.