Ruby’s GC Configuration

ruby_gc.sh

- http://www.coffeepowered.net/2009/06/13/fine-tuning-your-garbage-collector/
- http://snaprails.tumblr.com/post/241746095/rubys-gc-configuration

  article’s settings:                                     ("spec spec" took 17-23!sec)
	export RUBY_HEAP_MIN_SLOTS=1250000
	export RUBY_HEAP_SLOTS_INCREMENT=100000
	export RUBY_HEAP_SLOTS_GROWTH_FACTOR=1
	export RUBY_GC_MALLOC_LIMIT=30000000
	export RUBY_HEAP_FREE_MIN=12500

  37signals’s settings:                                   ("spec spec" took 17-18!sec)
	export RUBY_HEAP_MIN_SLOTS=600000
	export RUBY_HEAP_SLOTS_INCREMENT=10000
	export RUBY_HEAP_SLOTS_GROWTH_FACTOR=1.8
	export RUBY_GC_MALLOC_LIMIT=59000000
	export RUBY_HEAP_FREE_MIN=100000

  twitter’s settings:                                     ("spec spec" took 17-28sec)
	export RUBY_HEAP_MIN_SLOTS=500000
	export RUBY_HEAP_SLOTS_INCREMENT=250000
	export RUBY_HEAP_SLOTS_GROWTH_FACTOR=1
	export RUBY_GC_MALLOC_LIMIT=50000000
	export RUBY_HEAP_FREE_MIN=4096

  _default’s settings:                                     ("spec spec" took 25-37sec)
	export RUBY_HEAP_MIN_SLOTS=10000
	export RUBY_HEAP_SLOTS_INCREMENT=10000
	export RUBY_HEAP_SLOTS_GROWTH_FACTOR=1.8
	export RUBY_GC_MALLOC_LIMIT=8000000
	export RUBY_HEAP_FREE_MIN=4096

just copy-paste "exports" per each section and run into console.
then see the difference on specs or just applications logs

each result is specific to current codebase

you can also update your ~/.bash_rc or /etc/environment file with the variables