Heroku worker dyno produces file, how to read it from web dyno?

Question

When asked by the admin, my Heroku worker generates a report, compressed as a ~10MB ZIP file.

Generation takes about one minute, so it is done by delayed_job.
Once generation is done, where to store the file so that the web dyno can serve it?

• tmp folder is not the same from one dyno to another, it seems.
• Free database (5MB) is not large enough to contain the 10MB file

Is there no option besides storing the file in the database and paying to switch from 5MB to 20GB database?

Note: There is only one admin, and generating the report is a rare event.

Answer 1

What about just uploading the file onto Amazon S3 and having it accessed from there?