# Using ray for submitting async tasks from a FastAPI backend

**URL:** <https://discuss.ray.io/t/using-ray-for-submitting-async-tasks-from-a-fastapi-backend/5764>\
**Category:** Ray Core\
**Created:** [April 12, 2022, 9:01am UTC](https://discuss.ray.io/t/using-ray-for-submitting-async-tasks-from-a-fastapi-backend/5764 "2022-04-12T09:01:07Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![manangoel99](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.ray.io/manangoel99/32/2391_2.png) [@manangoel99](https://discuss.ray.io/u/manangoel99)\
**Post date:** [April 12, 2022, 9:01am UTC](https://discuss.ray.io/t/using-ray-for-submitting-async-tasks-from-a-fastapi-backend/5764/1 "2022-04-12T09:01:07Z")

</div>

**How severe does this issue affect your experience of using Ray?**

- High: It blocks me to complete my task.

I’m trying to create an app in which users can submit jobs to train models. The training should happen asynchronously so that other tasks aren’t blocked so I’m using a ray actor for that. The user can also then query if the task has finished or not.  
In order to do this I submit the job using `id = model.train.remote()` and store the id.  
Now while querying in a different function, I use `ready, not_ready = ray.wait([id], timeout=0)`. However, this always returns my job as not\_ready even though I can see on the ray dashboard that the function has stopped execution.  
However, using a blocking operation like this in the same function works but it blocks everything else.

```auto
id = model.train.remote()
ready, not_ready = ray.wait([id])

```

I’m not sure what the issue is here

---

<div class="post-metadata">

**Author:** ![Clark\_Zinzow](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.ray.io/clark_zinzow/32/445_2.png) [@Clark\_Zinzow](https://discuss.ray.io/u/Clark_Zinzow)\
**Post date:** [April 22, 2022, 4:59pm UTC](https://discuss.ray.io/t/using-ray-for-submitting-async-tasks-from-a-fastapi-backend/5764/2 "2022-04-22T16:59:04Z")

</div>

Hi @manangoel99, thank you for surfacing this! @sangcho @Stephanie_Wang if a future `id` is completed, would you expect `ray.wait([id], timeout=0)` to return it as ready? I would assume that the future check would happen even with the 0 timeout.

---

<div class="post-metadata">

**Author:** ![Clark\_Zinzow](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.ray.io/clark_zinzow/32/445_2.png) [@Clark\_Zinzow](https://discuss.ray.io/u/Clark_Zinzow)\
**Post date:** [April 22, 2022, 5:01pm UTC](https://discuss.ray.io/t/using-ray-for-submitting-async-tasks-from-a-fastapi-backend/5764/3 "2022-04-22T17:01:54Z")

</div>

Tried this myself and it appears that the future is returned ready, as expected:

```auto
In [1]: import ray; ray.init()

In [2]: @ray.remote
   ...: def foo():
   ...: return 1

In [3]: a = foo.remote()

In [4]: ready, not_ready = ray.wait([a], timeout=0)

In [5]: ready
Out[7]: [ObjectRef(c8ef45ccd0112571ffffffffffffffffffffffff0100000001000000)]

In [8]: not_ready
Out[8]: []
```