alt Hacker NewsSomething I never quite understood: differentiate between BEAM process and operating system process. The OS has launched one (in theory) BEAM Erlang VM runtime process with N threads; are we saying “process” here to try to emulate the OS process model internally within the BEAM OS process, when really we’re talking about threads? Or a mix of threads and other processes? I’m imagining the latter even cross network, but am I at least on the right track here?
A BEAM process is not an OS thread. The way I understand it, a BEAM process is just a very small memory space with its own heap/stack, and a message system for communication between BEAM processes.
The BEAM itself runs multiple OS threads (it can use all cores of the CPU if so desired), and the BEAM scheduler gives chunks of processing time to each BEAM process.
This gives you parallel processing out of the box, and because of the networking capabilities of the BEAM, also allows you to scale out over multiple machines in a way that's transparent to BEAM processes.