Memory usage increase with Ruby 2.1 versus Ruby 2.0 or 1.9

Question

I recently deployed an upgrade of Ruby from 2.0 to 2.1.5 to my Heroku web application, and I am consistently hitting memory quota errors now, whereas with 2.0 and 1.9 this never

Answer 1

This is a known issue with Ruby (versions 2.1.x) and its garbage collection. After reading couple of forums/blog posts there seems to be no real solution but to do one of the following:

• downgrade to ruby 2.0 and wait for ruby 2.2 to be released
• use unicorn worker killer to restart unicorn workers once they reach certain amount of memory, preventing Heroku R14 errors
• some suggest tweaking your GC variables (see here and here)

Here's a link to relevant discussion on ruby-lang.

Some people also noticed that one source of the problems could be NewRelic's gem so you might want to update/remove it and see if it helps.

Credits for some of the links and info to guys from upcase.com forum