Registry Processes

Name processes using the Registry

Until now, we used the process identifier obtained from starting the process to interact with it. However, we can optionally provide a :name value when starting a process. This can be used later instead of a PID. This way, we don’t have to keep track of the PIDs of the processes we start. Functions like GenServer.cast/2 and GenServer.call/3 also accept a name instead of a process identifier, and we’ve already seen how to use Process.whereis/1 to find out the PID for JobRunner.

To make working with names easier, Elixir comes with a module called Registry. It’s an efficient key-value store with some useful functionality. Let’s see how we can use it.

Processes can be named when they start via the :name option. This is what we did when creating JobRunner:

children = [
   {DynamicSupervisor, strategy: :one_for_one, name: Jobber.JobRunner},
]