Problem starting the scheduler in a separate node

[tnaftali]

I may be missing something here, but the following is happening to me: In my Phoenix web application, I'm trying to run exq and exq_scheduler on a separate worker node only, not the main web one, so I've set start_on_application: false in both configurations, this is the config.exs:

config :exq,
  name: Exq,
  host: "127.0.0.1",
  port: 6379,
  namespace: "exq",
  concurrency: 3,
  queues: ["default"],
  start_on_application: false,
  redis_timeout: 5000

config :exq_scheduler,
  storage: %{
    name: :exq_scheduler,
    exq_namespace: "exq",
    json_serializer: Jason
  },
  redis: %{
    name: ExqScheduler.Redis.Client,
    child_spec: {Redix, [host: "127.0.0.1", port: 6379, name: ExqScheduler.Redis.Client]}
  },
  schedules: %{
    test1: %{
      description: "Test",
      cron: "* * * * *",
      class: "Workers.Test",
      args: ["test"],
      queue: "default"
    },
    test2: %{
      description: "Test",
      cron: "*/2 * * * *",
      class: "Workers.Test",
      args: ["test2"],
      queue: "default"
    }
  },
  start_on_application: false

And this is in the application.ex start/2: worker_only_children = [Exq, ExqScheduler].

But I keep getting this error:

Now, if I put this in the application.ex:

    worker_only_children = [
      Exq,
      %{
        id: :exq_scheduler,
        start: {ExqScheduler, :start_link, [[schedules: []]]}
      }
    ]

The worker node successfully starts, so it seems to me like the exq_scheduler is not getting its config values when I try to manually start it with the application start. Does anyone know what could be causing this? Am I missing any config?

[ananthakumaran]

It's easier to set start_on_application on config/runtime.exs based on whether worker/web. If you want to start it manually, I would suggest looking at the Application module and checking how it's called. Specially, you would need to pass all the config explicitly and it won't be read from application config

[hebbo]

Seeing the same problem. The exq_scheduler seems to be able to read the app's configuration entries.

** (Mix) Could not start application tink_sync: MyApp.Application.start(:normal, []) returned an error: shutdown: failed to start child: ExqScheduler
    ** (EXIT) an exception was raised:
        ** (Protocol.UndefinedError) protocol Enumerable not implemented for nil of type Atom. This protocol is implemented for the following type(s): DBConnection.PrepareSt
ream, DBConnection.Stream, Date.Range, Ecto.Adapters.SQL.Stream, File.Stream, Function, GenEvent.Stream, HashDict, HashSet, IO.Stream, Jason.OrderedObject, List, Map, MapSet
, Postgrex.Stream, Range, Stream, Timex.Interval
            (elixir 1.13.4) lib/enum.ex:1: Enumerable.impl_for!/1
            (elixir 1.13.4) lib/enum.ex:199: Enumerable.slice/1
            (elixir 1.13.4) lib/enum.ex:969: Enum.empty?/1
            (exq_scheduler 1.0.0) lib/exq_scheduler.ex:21: ExqScheduler.start_link/1
            (stdlib 4.0.1) supervisor.erl:414: :supervisor.do_start_child_i/3
            (stdlib 4.0.1) supervisor.erl:400: :supervisor.do_start_child/2
            (stdlib 4.0.1) supervisor.erl:384: anonymous fn/3 in :supervisor.start_children/2
            (stdlib 4.0.1) supervisor.erl:1250: :supervisor.children_map/4
            (stdlib 4.0.1) supervisor.erl:350: :supervisor.init_children/2
            (stdlib 4.0.1) gen_server.erl:848: :gen_server.init_it/2
            (stdlib 4.0.1) gen_server.erl:811: :gen_server.init_it/6
            (stdlib 4.0.1) proc_lib.erl:240: :proc_lib.init_p_do_apply/3