Hello, I have an Elixir app where a process depends on another process to be alive and send messages back. This second process is mainly a database connection and may occasionally fail. I created an example app below, which mimics the structure. ModuleA my worker process, ModuleB is the database co…

So the supervisor you start in your application.ex uses the default of max 3 restarts within 5 seconds, before itself crashes. You’re doing 4 restarts per 5 seconds (restart A and B, wait 5 seconds and again restarting A and B). For :rest_for_one only the crashing ModuleB counts against that limit, …

Sure here you go: process-link-example/lib/test/application.ex at main · ream88/process-link-example · GitHub Its basically just started before ModuleA

Thanks @LostKobrakai , I thought about that, however I did not see it explicitly being mentioned in the docs ( Supervisor — Elixir v1.15.2 ). I always thought these options are applied per child spec!

:rest_for_one would hardly ever survive a single crash if it would count the restarts of the “rest”. For one_for_one both processes count, as A is restarted because it stopped, not because the supervisor stopped it.

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Understanding process links

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LostKobrakai July 18, 2023, 7:45am 2

How is ModuleB started in your second example? Do you have the code up in a repo somewhere?