Threading Optimization for Rails with Perfm | Talk.rb

This text is the third part of a blog series discussing scaling Rails applications, focusing on determining the ideal number of threads per process. It explains how the Global Virtual Machine (GVL) affects thread states and introduces a tool called perfm for instrumenting the GVL to measure thread behavior in production applications. By analyzing metrics like I/O percentage and average stall time using perfm, the article demonstrates how to practically validate a theoretical thread count derived from Amdahl's Law. The author concludes that for well-optimized Rails applications, a max_threads value around 3 is often optimal to balance concurrency and minimize GVL contention.

Links:
bigbinary.com/blog/tuning-puma-max-threads-configu…

Official Resources:
www.ruby-lang.org/
ruby-doc.org/
rubyonrails.org/