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by Grollicus 194 days ago
That's intersting to see.

Does the api support progress reporting? ("30 % done")

Of course one could build this manually when you're building the worker implementation but I'd love to have it reflected in the api somewhere. Celery also seems to be missing api for that.

Anyone sees a reason why that's missing? I don't think it complicates the api much and seems such an obvious thing for longer-running background tasks.

2 comments

To implement progress reporting, it means you are able to know the time a task would take to run upfront, no? Is it even possible to do it accurately ?

Though, I imagine you could have strategies to give an approximation of it, for example like keeping track of the past execution time of a given type of task in order to infer the progress of a currently running task of the same type.

> To implement progress reporting, it means you are able to know the time a task would take to run upfront, no?

No. You just need to know the total number of steps and what step are you currently on.

You're right, but I also don't find a way a task queue library could know that upfront either to implement progress reporting.

Does anyone know a task queue library that implement it ? I would be curious to look at it !

The way it's typically done is that the worker process reports back its progress to the job metadata on the queue, and the web worker polls the job metadata to read the progress. I've implemented this for progress bars many times on Django with django-rq.

I first learned about it from Miguel Grinberg's Flask tutorial: https://blog.miguelgrinberg.com/post/the-flask-mega-tutorial... But the same concept applies to Django.

I had previously asked about this. My understanding is that there is a desire to add functionality to allow this, but in this first release the task system is intentionally very lightweight.
Do you have any source one could follow? mail thread, bug tracker issue, ..?
This is the repo where the development of django-tasks is happening: https://github.com/realOrangeOne/django-tasks