How to initialize an ETS table in Phoenix?

I’m currently using Redis to cache some information in my application. But I saw that ETS may be faster at lookup actions (https://github.com/minhajuddin/redis_vs_ets_showdown) . With that in mind, I want to create an ETS table at my app startup, so I can use it in a Plug.

I’ve tried to the following, but it did not work.

defmodule MyApp.Validator do
    @bucket :ets.new(:bucket, [:set, :protected])

    def put_validation(id) do
        :ets.insert_new(@bucket, {id, %{"active" => true, "user" => "test"}}
    end
end

It returns argument error. I think it’s because the ETS does not exist.

How and where can I initialize an ETS in order to use it inside my application?