supervisor

Supervisors are one of the most important features of OTP. They monitor other processes and take action if anything goes wrong, restarting the failed process or possibly escalating the problem to a higher level. Layering supervisors into supervision trees allows you to create highly fault-tolerant systems. (Logan, Merritt, and Carlsson 2010)

A simple-one-for-one supervisor hierarchy. All the child processes are of the same type and are added or removed dynamically. There can be any number of them.