Heapfrag

This tool allows to measure a fragmentation of the Ruby VM heap.

Installation

Add this line to your application's Gemfile:

gem 'heapfrag'

And then execute:

$ bundle

Or install it yourself as:

$ gem install heapfrag

Usage

> require "heapfrag"
> Heapfrag::stat

{
  :fragmented_pages=>146, # num of non full and non empty
  :pages_total=>154,
  :pages_seen=>154,
  :pages_with_alive=>154, # pages with used slots
  :pages_with_dead=>146,  # pages with free slots
  :pages_free=>0,         # pages completelly free
  :pages_full=>8,         # pages completelly full
  :objs_alive=>47812,     # used slots
  :objs_dead=>14961,      # free slots
                         0% 50% 95%  99% 99.9% 100%
  :heap_pages_fill_cdf=>[0, 22, 116, 133, 142, 154]
}

fragmented = total - full - empty

Quick start

$ rake compile && echo 'require "heapfrag"; Heapfrag::stat' | irb
install -c tmp/x86_64-linux/heapfrag/2.4.10/heapfrag.so lib/heapfrag/heapfrag.so
cp tmp/x86_64-linux/heapfrag/2.4.10/heapfrag.so tmp/x86_64-linux/stage/lib/heapfrag/heapfrag.so
Switch to inspect mode.
require "heapfrag"; Heapfrag::stat
{:fragmented_pages=>146, :pages_total=>154, :pages_seen=>154, :pages_with_alive=>154, :pages_with_dead=>146, :pages_free=>0, :pages_full=>8, :objs_alive=>47812, :objs_dead=>14961, :heap_pages_fill_cdf=>[0, 22, 116, 133, 142, 154]}

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/sitano/heapfrag. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

License

The gem is available as open source under the terms of the MIT License.