Ash.load with timeout option seems to be ignored with custom read_action

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1

In my resource, I have this relationship:

    has_one :similar_grantee_entity, Entity do
      no_attributes? true

      read_action :read_in_temp

      filter expr(...)
    end

In my code, I load it using:

Ash.load!(records, :similar_grantee_entity, timeout: :infinity)

As you can see, I’m setting the timeout option, but even with that, I’m getting the following error:

** (Ash.Error.Invalid)
Bread Crumbs:
  > Error returned from: Core.Pacman.Markets.Entity.read_in_temp
  > Error returned from: Core.Pacman.Markets.Record.read

Invalid Error

* Core.Pacman.Markets.Entity.read_in_temp timed out after 180000ms.

The default timeout can be configured on the domain,

    execution do
      timeout :timer.seconds(60)
    end

Each request can be configured with a timeout via `Ash.Changeset.timeout/2` or `Ash.Query.timeout/2`.

    at similar_grantee_entity
  (ash 3.5.6) lib/ash/error/invalid/timeout.ex:5: Ash.Error.Invalid.Timeout.exception/1
  (ash 3.5.6) lib/ash/process_helpers.ex:86: Ash.ProcessHelpers.task_with_timeout/5
  (ash 3.5.6) lib/ash/actions/read/read.ex:970: Ash.Actions.Read.maybe_in_transaction/3
  (ash 3.5.6) lib/ash/actions/read/read.ex:326: Ash.Actions.Read.do_run/3
  (ash 3.5.6) lib/ash/actions/read/read.ex:89: anonymous fn/3 in Ash.Actions.Read.run/3
  (ash 3.5.6) lib/ash/actions/read/read.ex:88: Ash.Actions.Read.run/3
  (ash 3.5.6) lib/ash/actions/read/relationships.ex:542: anonymous fn/3 in Ash.Actions.Read.Relationships.do_fetch_related_records/5
    (ash 3.5.6) lib/ash/error/invalid.ex:3: Ash.Error.Invalid.exception/1
    (ash 3.5.6) /home/runner/work/platform/platform/core/deps/splode/lib/splode.ex:264: Ash.Error.to_class/2
    (ash 3.5.6) lib/ash/error/error.ex:108: Ash.Error.to_error_class/2
    (ash 3.5.6) lib/ash/actions/read/read.ex:414: anonymous fn/3 in Ash.Actions.Read.do_run/3
    (ash 3.5.6) lib/ash/actions/read/read.ex:342: Ash.Actions.Read.do_run/3
    (ash 3.5.6) lib/ash/actions/read/read.ex:89: anonymous fn/3 in Ash.Actions.Read.run/3
    iex:10: (file)

Is this a bug?

2

:thinking: interesting. I think it may be, but it’s a bit complicated. The load itself does a read which has a timeout on it, and I don’t think we do anything to indicate to load read actions that they should adopt the parent’s timeout, and its not entirely clear if they should adopt the parent’s timeout TBH. Its…unclear :slight_smile:

You could conditionally add the timeout in the target action for only when its being run directly by switching on the presence of query.context[:accessing_from] I believe.

3

But if I don’t specify a read_action then the load would respect the timeout value correct?

At least that is what I would expect from a timeout field in a load call haha. And, of course, if that is the case, I would expect the same to be true if the read_action is set as that is just a implementation detail that the caller (the one doing the load) doesn’t need to concern about it.

4

I actually think that this particular behavior is more correct, considering multiple options. The concept is that when loading relationships we honor the rules on the relevant read action. That action is, by default, the primary read action. You’ve set a timeout on that read action, which means it applies when being used to load relationships also.

5

By “this particular behavior” you mean applying the load timeout value to all read calls the function does behind the scene or the other way around?

You’ve set a timeout on that read action, which means it applies when being used to load relationships also.

Where was that set actually? What I set was only a custom read action with the read_action option and then I set the load timeout in the load call which I expected to be applied to that custom read call too.

6

Think about it like this:

with_timeout(:infinity, fn -> 
  # this timeout is where the error comes from
  with_timeout(180000, fn -> 
     :timer.sleep(500000)
  end)
end)

The related action used for the read has a timeout. Just because the outer action call has an infinite timeout, it still calls something with its own shorter timeout.

7

Ah, I see, but in that case, shouldn’t the inner call inherit the timeout of the outer call? Otherwise, what exactly is the point of the timeout option in a load call?

8

Actually, what exactly does the timeout in the load function do? Will it not set the relationship load query timeout too?

9

The timeout passed to the load is “how long to wait for all loads”, not a value to use for each individual load.

10

In that case, how can someone set/customize the individual loads timeout value?

11

You’d need to do one of:

  • use a different action
  • In the action, set the timeout conditionally depending on something like context, and load with that, I.e load(foo: Ash.Query.set_timeout(...))
  • Use relationship context and switch on that in the destination action conditionally, i.e
has_many ... do
  context %{...}
end