[Solved]-How to serialize binary files to use with a celery task


You are correct that celery tries to pickle data for which pickling is unsupported. Even if you would find a way to serialize data you want to send to celery task, I wouldn’t do this.

It is always a good idea to send as little data as possible to the celery tasks, so in your case I would pass only the id of a UserUploadedFile instance. Having this you can fetch your object by id in celery task and perform convert_to_others() .

Please also note that the object could change its state (or it could even be deleted) before the task is executed. So it is much safer to fetch the object in your celery task instead of sending its full copy.

To sum up, sending only an instance id and refetching it in task gives you a few things:

  • You send less data to your queue.
  • You do not have to deal with data inconsistency issues.
  • It’s actually possible in your case. 🙂

The only ‘drawback’ is that you need to perform an extra, inexpensive SELECT query to refetch your data, which in overall looks like a good deal, when compared to above issues, doesn’t it?


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