From: Ryan Davis <ryand-ruby@...>
Date: 2009-04-17T09:39:01+09:00
Subject: Re: Weird performance issue


On Apr 16, 2009, at 16:25 , court3nay wrote:

> Hey, I'm debugging a weird performance issue. I have two VMs on the
> same server running the same OS (arch linux) and the same version of
> "enterprise" Ruby (ruby 1.8.6 (2008-08-08 patchlevel 286) [x86_64-
> linux]).
>
> On one machine, I get these numbers
>
> irb(main):004:0> Benchmark.realtime { require 'rubygems' }
> => 0.0482780933380127
> irb(main):005:0> Benchmark.realtime { require 'tinder' }
> => 0.395686149597168
>
> On the other,
>
> irb(main):002:0> Benchmark.realtime { require 'rubygems' }
> => 1.20596885681152
> irb(main):003:0> Benchmark.realtime { require 'tinder' }
> => 5.7661280632019

same number of gems on both slices?

% gem list | wc -l

you can also do something really gross like:

% ruby -rtracer -e 'require "rubygems"' > server1.txt

I don't think you should necessarily diff the two, but looking at  
rough things like # of lines should start to explain stuff. Something  
maybe like:

% ruby -rtracer -e 'require "rubygems"' | cut -f 2 -d : | occur | head
41672: /Library/Ruby/Site/1.8/rubygems/specification.rb
38352: /Library/Ruby/Site/1.8/rubygems/version.rb
  3865: /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ 
ruby/1.8/universal-darwin9.0/rbconfig.rb
  3544: /Library/Ruby/Site/1.8/rubygems/requirement.rb
  3491: /Library/Ruby/Site/1.8/rubygems/gem_path_searcher.rb
  3173: /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ 
ruby/1.8/fileutils.rb
  2329: /Library/Ruby/Site/1.8/rubygems/source_index.rb
  1213: /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ 
ruby/1.8/date.rb
  1087: /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ 
ruby/1.8/optparse.rb
   847: /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ 
ruby/1.8/yaml/tag.rb

(occur is a simple script I wrote to aggregate input... I loves it)