Raindrops Aggregate Aggregate::LastDataRecv Aggregate::PMQ LastDataRecv Linux ListenStats Middleware Middleware::Proxy Middleware::Stats Struct Watcher

raindrops - real-time stats for preforking Rack servers

raindrops is a real-time stats toolkit to show statistics for Rack HTTP servers. It is designed for preforking servers such as unicorn, but should support any Rack HTTP server on platforms supporting POSIX shared memory. It may also be used as a generic scoreboard for sharing atomic counters across multiple processes.


Linux-only Extra Features!

Users of older Linux kernels need to ensure that the the "inet_diag" and "tcp_diag" kernel modules are loaded as they do not autoload correctly


We recommend GCC 4+ (or compatible) to support the atomic builtins (_syncadd,sub}_and_fetch()). For non-GCC 4+ users, we also support compilation with the {libatomic_ops package starting with Raindrops 0.4.0.

If you're using a packaged Ruby distribution, make sure you have a C compiler and the matching Ruby development libraries and headers.

If you use RubyGems:

gem install raindrops

Otherwise grab the latest tarball from:

Unpack it, and run "ruby setup.rb"


See Raindrops::Middleware and Raindrops::LastDataRecv documentation for use Rack servers. The entire library is fully-documented and we are responsive on the mailing list ( if you have any questions or comments.


You can get the latest source via git from the following locations:

git:// (mirror)

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

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 raindrops patches.

raindrops is licensed under the LGPL+2.1 or later:


All feedback (bug reports, user/development discussion, patches, pull requests) go to the mailing list:

Mailing list archives are available here:

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