An experimental auto-scaler for the unicorn web server
Latest commit c68c394 Jun 18, 2013 @bensomers bumping version to 0.4.2


Alicorn: Auto-scaler for Unicorn webserver

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An experimental auto-scaler for the Unicorn webserver. Designed for Unicorn webservers running with the Raindrops middleware enabled. It depends on the “active” and “queued” fields reported by Raindrops, and so only works on Linux.


Alicorn ships with two executables, alicorn and alicorn-profiler.

alicorn: this is the main command-line utility: run alicorn –help to see the list of options and learn how to configure it.

alicorn-profiler: this is a tool to help determine useful parameters for alicorn. it's recommended that you run alicorn in dry-run and verbose mode for awhile, collect the resulting logs, and feed those through alicorn-profiler to get a handle on what settings you'll need. Same story, run alicorn-profiler –help to figure out what the options are and how you can tweak them.


Alicorn attempts to follow the Semantic Versioning Specification. Every release in the 0.x series should be considered a DEVELOPMENT version. The public API should not be considered stable.


  • Check out the latest master to make sure the feature hasn't been implemented or the bug hasn't been fixed yet.

  • Check out the issue tracker to make sure someone already hasn't requested it and/or contributed it.

  • Fork the project.

  • Start a feature/bugfix branch.

  • Commit and push until you are happy with your contribution.

  • Make sure to add tests for it. This is important so I don't break it in a future version unintentionally.

  • Please try not to mess with the Rakefile, version, or history. If you want to have your own version, or is otherwise necessary, that is fine, but please isolate to its own commit so I can cherry-pick around it.


Alicorn is maintained by Ben Somers and is funded by Rafter. Huge thanks to Eric Wong and the rest of the Unicorn and Raindrops contributors.


Copyright © 2012 Ben Somers. See LICENSE.txt for further details.