> Beam doesn't have anything to do with supervisors that's an OTP thing.
The key VM feature you're missing is process isolation. Without it, supervisors are not really possible - you can implement something that vaguely looks like them, but it won't provide the fault tolerance guarantees.
Imagine for example an Erlang process that leaks files. At some point it hits an EMFILE, gets killed, and the supervisor restarts it. The system will then go back to operating normally.
Now imagine a Goroutine doing the same. It hits EMFILE, exits, and the supervisor restarts it. This doesn't help anything: it just hits the same error and the system is unusable. There's no way for the VM to guarantee cleanup when a Goroutine exits, because it doesn't isolate Goroutines and track which one owns which resources.
Links and monitors are tools to extend the same behavior to user-managed resources like DB connections and so on. The responsibility for cleanup if a process crashes while holding a DB connection falls on the DB connection library, not on the error handling inside the crashing process.
The key VM feature you're missing is process isolation. Without it, supervisors are not really possible - you can implement something that vaguely looks like them, but it won't provide the fault tolerance guarantees.
Imagine for example an Erlang process that leaks files. At some point it hits an EMFILE, gets killed, and the supervisor restarts it. The system will then go back to operating normally.
Now imagine a Goroutine doing the same. It hits EMFILE, exits, and the supervisor restarts it. This doesn't help anything: it just hits the same error and the system is unusable. There's no way for the VM to guarantee cleanup when a Goroutine exits, because it doesn't isolate Goroutines and track which one owns which resources.
Links and monitors are tools to extend the same behavior to user-managed resources like DB connections and so on. The responsibility for cleanup if a process crashes while holding a DB connection falls on the DB connection library, not on the error handling inside the crashing process.