Notes about elixir processes

Live list of stuff I learn about elixir processes. Some of them are stupid mistakes I make, some of them are more tricky gotchas

• meaning of :restart values in the child spec:
  • :permanent: always restart (default)
  • :temporary: never restart
  • :transient: restart only on abnormal termination
• :normal exist doesn't bring down linked processes.
• but :shutdown does. This is how supervision shutdown propagates down the tree.
• The documentation says trapping exits makes it hard to exit when you need to. Take this advice seriously.
• If you try to “shut down” a process with GenServer.stop/1, it will be restarted by the (dynamic) supervisor. There is DynamicSupervisor.terminate_child/1, that should be used.
• Consider using the supervisor_bridge module if you are working on processes that work in a non-typical way.