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Supercharge the One Person Framework with SQLite: Rails World 2024

Manipulating database.yml

This is the second in a series of posts on building powerful and resilient Rails application templates. In the previous post, we discussed parsing and emitting YAML files with comments. Today, we will be looking at manipulating the database.yml file’s AST.

Parsing and emitting database.yml

Recently, I have been working on Rails application templates. These are scripts that can be run with rails new to enhance or extend the setup of a new Rails application with a specific configuration. They can also be ran against existing Rails applications using rails app:template. So, they are a powerful tool for automating certain kinds of configuration, modification, and setup tasks. But, there are also many limitations and stumbling blocks to what you can do with them.

In this series, I will be sharing some of the things I have learned while working on these scripts. This post is about the difficulty of manipulating the database.yml file. Let’s jump into it.

Problems with a backoff busy handler

In the process of getting the non-blocking busy_timeout from the sqlite3 gem used in Rails, I needed to explore the differences between a busy handler implementation that uses a backoff and one that simply polls on a consistent interval. What I found was that a busy handler that backs off kills “tail latency” (how long it takes for the operation in the worst cases). This is because the SQLite “retry queue” behaves very differently from a more traditional queue that we tend to work with and think about, like a background job queue.

Update to Litestream gem

Version 0.5.1 of the Litestream is out. The 0.5.x versions of the gem adds a new restore command along with some useful introspection commands, making it simple to restore a database from a remote backup. This is a huge feature that makes Litestream even more useful.

The how and why of optimal performance

Update to Solid Errors

Version 0.4.2 of Solid Errors is out. The 0.4.x versions of the gem adds a number of awesome new features, most notably email notifications. If you need a self-hosted error tracking solution for your Rails application, Solid Errors is a great choice.

Isolated connection pools

If you want to squeeze as much performance out of your SQLite on Rails application, at some point you will need to confront the problem of writes saturating your connection pool. Let’s dig into this problem and how to solve it with some clever usage of Rails’ multi-database support.

Introducing Solid Errors

Solid Errors is a Rails engine that provides a dashboard for viewing and resolving exceptions in your Rails application without the need for an external 3^rd party service. With version 0.3.0, I am happy to announce that Solid Errors is now ready for production use.

Radio Pills with Tailwind

Here is a quick tip on building “radio pills” with TailwindCSS, inspired by Scott O’Hara’s brilliant work. The goal here is to make an accessible form element that also has visual polish and purpose.¹