Rails Performance Gems and Tricks

A small collection of gems and tricks I use for measuring and enhancing a Rails app performance. I’ll keep this post updated with new gems and tricks :)

Gems

• (Benchmark) rack-mini-profiler. Profiler for your development and production Ruby rack apps
• (Benchmark) ruby-prof. A code profiler for MRI rubies (Thanks Ana María!)
• (Benchmark) derailed_benchmarks. Benchmarks for your whole Rails app
• (Cache) bootsnap. Boot large Ruby/Rails apps faster
• (Database/Queries) bullet. Easy detecting N+1 queries
• (Database/Queries) ankane/dexter. The automatic indexer for Postgres
• (Heroku only) heroku-deflater. Add the gem on the production group and enjoy gziped served assets

Tips

• Use Rack::Deflater (Original post. Thanks Schneeman!)

This tip is incredible! It just uses a Rack stdlib to compress your HTML.

Add the config.middleware.insert_after ActionDispatch::Static, Rack::Deflater line on your config/application.rb, and voilà!

• Set a reasonable MALLOC_ARENA_MAX if you have memory bloat (Original post. Thanks Nate!)

Ruby memory allocation can be tricky, as this post is a very deep analysis on what’s going on behind the curtains.