With Heroku's free tier gone, this is my work-in-progress configuration for a new ruby on rails apps that I want to run as cheaply as possible.
Here's the gist of it:
- Rails.cache uses
:file_store - Use SQLite for a database
- Use redis for sidekiq and actioncable
- Run Sidekiq in embedded mode
- Use
disk_storagefor ActiveStorage - Run ActionCable's websocket server in embedded mode
- Use hatchbox to deploy all of my apps on a single VPS on linode/vultr/aws/digital ocean
- Use Cloudflare as a CDN
The main theme here is taking advantage of how cheap disk storage is on VPS providers (~$0.10 per GB) as well as Hatchbox allowing unlimited apps to be deployed on a single machine. The cost per months follows this formula:
cost = ($10 per server + VPS cost) / # of apps
So if I had 10 apps running a single $5 Linode server and each app would cost me $1.50 per month. 100 apps on a $40 server would cost my $50 / 100 apps = $0.50 per app.
Caveats
This stack does make some assumptions about the app ideas I have:
- a lot of reads and very few writes
- very small chance of going viral
- low to medium traffic
- wary of every gem you use to manage memory usage
And this stack does nudge coding your app a certain way to squeeze as many apps as possible in a single server:
- heavily use russian doll caching
- SQLite should be running in WAL mode
- Sidekiq workers should not do anything that requires a lot of compute (adding things together, reading files, etc).
- Remove cookies from page responses so that they can be cached in a CDN and use lazy turbo frames to fetch user specific content.
Possible further optimizations
This same configuration could be done on fly.io instances in addition to scaling down to 0 after hitting idle timeout. I learned about this here. Although I don't have a lot of experience optimizing rails boot times in order to respond to a waking request fast enough. Given what has happened to heroku, I'd bet that a simple VPS provider would outlast a niche platform-as-a-service.
If anyone is interested in a tutorial, let me know.
Thanks for reading!
I am partially running this stack (sqlite and file_store caching) in production today at reipricetracker. If you are concerned about performance, you can see the top left speed badge be adding ?rails=1 to any URL.
Top comments (3)
Interested if there is a tutorial about this, thanks!
hi!
Great summary.
Could you share your sidekiq config? I think that would be useful to see what number of threads, workers and what you ended up using. cheers!
Great post. Thank you for sharing!