Rainbows! Unicorn for sleepy apps and slow clients

Rainbows! is an HTTP server for sleepy Rack applications. It is based on Unicorn, but designed to handle applications that expect long request/response times and/or slow clients. For Rack applications not heavily bound by slow external network dependencies, consider Unicorn instead as it simpler and easier to debug.

Rainbows! is about Diversity

We aim to support as many concurrency models as we can because they all suck; differently.

For network concurrency, models we currently support are:

We have many more on the way for handling network concurrency. Additionally, we also use multiple processes (managed by Unicorn) for robustness and CPU/memory/disk concurrency.

We also provide Rainbows::AppPool Rack middleware for some network concurrency models for limiting application concurrency independently of network concurrency.

Features

Designed for Rack, the standard for modern Ruby HTTP applications.
Built on Unicorn, inheriting its process/socket management features such as transparent upgrades and Ruby configuration DSL.
As with Unicorn, it is able to stream large request bodies off the socket to the application while the client is still uploading. Since Rainbows! can handle slow clients, this feature is more useful than it is with Unicorn.
Combines heavyweight concurrency (worker processes) with lightweight concurrency (Events/Fibers/Actors/Threads), allowing CPU/memory/disk to be scaled independently of client connections. More concurrency models (listed in the TODO) will be supported as we find time for them.
We give you lots of options with more on the way.

Applications

Rainbows is mainly designed for the odd things Unicorn sucks at:

Web Sockets (via Sunshowers)
3rd-party APIs (to services outside your control/LAN)
OpenID consumers (to providers outside your control/LAN)
Reverse proxy implementations with editing/censoring (to upstreams outside your control/LAN)
Comet
BOSH (with slow clients)
HTTP server push
Long polling
Reverse AJAX
real-time upload processing (via upr)

Rainbows can also be used to service slow clients directly even with fast applications.

License

Rainbows! is 100% Free Software.

Install

You may download the tarball from the Rainbows project page on Rubyforge and run setup.rb after unpacking it:

rubyforge.org/frs/?group_id=8977

You may also install it via RubyGems on Gemcutter:

  gem install rainbows

Usage

for Rack applications

In APP_ROOT (where config.ru is located), run:

  rainbows

Rainbows! will bind to all interfaces on TCP port 8080 by default.

Configuration File(s)

Rainbows! will look for the config.ru file used by rackup in APP_ROOT.

For deployments, it can use a config file for Unicorn and Rainbows!-specific options specified by the --config-file/-c command-line switch. Rainbows! accepts all options found in Unicorn::Configurator as well as the “Rainbows!” block, so you can have the following in your config file:

    worker_processes 4 # assuming four CPU cores
    Rainbows! do
      use :FiberSpawn
      worker_connections 100
    end

See the Rainbows! configuration documentation for more details.

Development

You can get the latest source via git from the following locations (these versions may not be stable):

  git://git.bogomips.org/rainbows.git
  git://repo.or.cz/rainbows.git (mirror)

You may browse the code from the web and download the latest snapshot tarballs here:

git.bogomips.org/cgit/rainbows.git (cgit)
repo.or.cz/w/rainbows.git (gitweb)

Inline patches (from “git format-patch”) to the mailing list are preferred because they allow code review and comments in the reply to the patch.

We will adhere to mostly the same conventions for patch submissions as git itself. See the Documentation/SubmittingPatches document distributed with git on on patch submission guidelines to follow. Just don’t email the git mailing list or maintainer with Rainbows! patches.

Disclaimer

There is NO WARRANTY whatsoever if anything goes wrong, but let us know and we’ll try our best to fix it.

Contact

All feedback (bug reports, user/development discussion, patches, pull requests) go to the mailing list/newsgroup. Patches must be sent inline (git format-patch -M + git send-email). No subscription is necessary to post on the mailing list. No top posting. Address replies To: the mailing list.

email: rainbows-talk@rubyforge.org
nntp: nntp://news.gmane.org/gmane.comp.lang.ruby.rainbows.general
subscribe: rubyforge.org/mailman/listinfo/rainbows-talk
archives: rubyforge.org/pipermail/rainbows-talk

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