I have a telegram bot with a Postgres DB hosted on Heroku Free dyno. In one stage of my code, I want to save pickled files permanently so that I can access them later. Storing it on a table doesn't feel like a nice idea as it is a nested class with a variable number of inputs. Problem is that Heroku deletes these files frequently or at least on each restart or push. Is there any way to tackle this problem?
You have to use external services such as AWS S3, GCP Cloud Storage (Buckets), Azure Blob Storage etc.. for that. Or you may consider using an addon such as Felix Cloud Storage, Cloud Cube, Bucketeer, HDrive for easy integration.
Here is what the documentation states:
The Heroku filesystem is ephemeral - that means that any changes to the filesystem whilst the dyno is running only last until that dyno is shut down or restarted. Each dyno boots with a clean copy of the filesystem from the most recent deploy. This is similar to how many container based systems, such as Docker, operate.
In addition, under normal operations dynos will restart every day in a process known as "Cycling".
These two facts mean that the filesystem on Heroku is not suitable for persistent storage of data. In cases where you need to store data we recommend using a database addon such as Postgres (for data) or a dedicated file storage service such as AWS S3 (for static files). If you don't want to set up an account with AWS to create an S3 bucket we also have addons here that handle storage and processing of static assets https://elements.heroku.com/addons