Configuring database connections in the Active Record connection pool for apps running with a multi-threaded or multi-process web server.| devcenter.heroku.com
This guide covers how to attach files to your Active Record models.After reading this guide, you will know: How to attach one or many files to a record. How to delete an attached file. How to link to an attached file. How to use variants to transform images. How to generate an image representation of a non-image file, such as a PDF or a video. How to send file uploads directly from browsers to a storage service, bypassing your application servers. How to clean up files stored during testing. ...| Ruby on Rails Guides
A guide to using Puma on Heroku. Puma uses threads, in addition to worker processes, to make more use of a systems available CPU.| devcenter.heroku.com
A short post on a technique you can use to see what is using your Rails app's ActiveRecord connections.| tekin.co.uk
