Increased memory and cpu usage when migrating from MRI 1.8.6 to REE 1.8.7

Hello,

We’ve been migrating our fairly large Rails 1.2 application from MRI 1.8.6 to REE 1.8.7, and in the process we’ve encountered some fairly odd behavior.

Namely, instead of the expected reduction in memory usage, we’re seeing an increase in memory usage by around 40% and, along with it, an increase in processor usage.

The stock 1.8.7 implementation performs even worse than REE from both standpoints, and while this is somewhat redeeming of REE, something is most definitely amiss.

Tweaking REE’s GC parameters was our first instinct, but the improvements we got that way were negligible.

The question is, has anyone experienced anything similar? Is there something we’re missing?

If there’s anything I’ve left out that might be helpful, please point it out and I’ll be more than happy to answer.

1.2 (if my memory is correct) predates ruby 1.8.7. I think the first officially 1.8.7 friendly rails version was 2.1. It might be worth scanning those commits pertaining to 1.8.7 compatibility to see if there is anything that seems relevant

It seems to be the case: http://weblog.rubyonrails.org/2008/6/26/this-week-in-rails-june-26-2008

If you are using Rails 2.1, Ruby 1.8.7-p22 seems the way to go. Unfortunately, Ruby 1.8.7 is not compatible with previous versions of Rails.