Feature: Celery Retry

[willseward]

Is the anyway you could add a .RetryAfter(callable) to the celery node?

At the moment I'm confuse about how the celery task goes from the Error state to the Retry state. It doesn't look like there any automatic process to handle that. Please correct me if I'm wrong.

[kmmbvnr]

The retry is the action of the JobActivation Generally different UI solutions could be implemented to call it.

To make it consistent with other flow actions, same sort of code like CancelViewMixin need to be added

[willseward]

Ok. I see how you can implement it with the UI now. Thanks!

What do you think about checking for a retry flag around here: https://github.com/viewflow/viewflow/blob/master/viewflow/decorators.py#L92 ? I was thinking that if a retry value has been set via .RetryAfter(), the task would automatically reschedule itself upon error.

[kmmbvnr]

I don't think that it should be in viewflow. Celery have own way to retry the task - http://docs.celeryproject.org/en/latest/userguide/tasks.html#retrying

[willseward]

Agreed, but viewflow throws an error saying that there is transition from Error to Done when it is retried via celery. It would be an easy fix to change the task status to Retry in the celery task, but you suggest avoiding modifying the state in the task itself because nothing is locked.