heap_inspect

HeapInspect

A CLI for analyzing Ruby Heap dumps. Thanks to Sam Saffron for the idea and initial code.

Installation

Add this line to your application's Gemfile:

gem 'heap_inspect'

And then execute:

$ bundle

Or install it yourself as:

$ gem install heap_inspect

Usage

Step 1) Generate a heap dump. You could do this manually. Or you can use a tool like derailed_benchmarks

Step 2) Once you've got the heap dump, you can analyze it using this CLI:

$ heap_inspect read tmp/2015-10-01T10:18:59-05:00-heap.dump

Generation:  0 object count: 209191
Generation: 14 object count: 407
Generation: 15 object count: 638
Generation: 16 object count: 748
Generation: 17 object count: 1023
Generation: 18 object count: 805
# ...

Generally early generations will have a high object count as an app is initialized. Over time however, the object count should stabalize. If however you see it spike up, you can drill down into a specific generation. In the previous example, the 17'th generation looks strangely large, you can drill into it:

$ heap_inspect read tmp/2015-10-01T10:18:59-05:00-heap.dump 17
    Analyzing Heap (Generation: 17)
    -------------------------------

    allocated by memory (in bytes)
    ==============================
    /Users/richardschneeman/Documents/projects/codetriage/app/views/layouts/application.html.slim:1 (Memory: 377065, Count: 1 )
    /Users/richardschneeman/.gem/ruby/2.2.3/gems/actionview-4.2.3/lib/action_view/template.rb:296 (Memory: 35814, Count: 67 )
    /Users/richardschneeman/.gem/ruby/2.2.3/gems/activerecord-4.2.3/lib/active_record/attribute.rb:5 (Memory: 30672, Count: 426 )

You can also use T-Lo's online JS based Heap Analyzer for visualizations.

Development

After checking out the repo, run $ bundle install to install dependencies. Then, run rake spec to run the tests.

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/[USERNAME]/heap_inspect. 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.