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tag namev5.0.0 (0ed773345ab0d7f0068340d2963f4d547c302199)
tag date2015-11-01 08:48:57 +0000
tagged byEric Wong <e@80x24.org>
tagged objectcommit f8d431040e...
unicorn 5.0.0 - most boring major release. EVER.
An evolutionary dead-end since its announcement[1] nearly six years
ago, this old-fashioned preforker has had enough bugs and missteps
that it's managed to hit version 5!

I wish I could say unicorn 5 is leaps and bounds better than 4, but
it is not.  This major version change allows us to drop some cruft
and unused features which accumulated over the years, resulting in
several kilobytes of memory saved[2]!


* The horrible, proprietary (:P) "Status:" response header is
  finally gone, saving at least 16 precious bytes in every HTTP
  response.  This should make it easier to write custom HTTP clients
  which are compatible across all HTTP servers.  It will hopefully
  make migrating between different Rack servers easier for new

* Ruby 1.8 support removed.  Ruby 1.9.3 is currently the earliest
  supported version.  However, expect minor, likely-unnoticeable
  performance regressions if you use Ruby 2.1 or earlier.  Going
  forward, unicorn will favor the latest version (currently 2.2) of
  the mainline Ruby implementation, potentially sacrificing
  performance on older Rubies.

* Some internal, undocumented features and APIs used by
  derivative servers are gone; removing bloat and slightly lowering
  memory use.  We have never and will never endorse the use of any
  applications or middleware with a dependency on unicorn,
  applications should be written for Rack instead.
  Note: Rainbows! 5.0 will be released next week or so to be
  compatible with unicorn 5.x

New features:

* sd_listen_fds(3) emulation added for systemd compatibility.
  You may now stop using PID files and other process monitoring
  software when using systemd.

* Newly-set TCP socket options are now applied to inherited sockets.

* Dynamic changes in the application to Rack::Utils::HTTP_STATUS
  hash is now supported; allowing users to set custom status lines
  in Rack to be reflected in unicorn.  This feature causes a minor
  performance regression, but is made up for Ruby 2.2 users with
  other optimizations.

* The monotonic clock is used under Ruby 2.1+, making the
  timeout feature immune to system clock changes.

As unicorn may be used anonymously without registration, the
project is committed to supporting anonymous and pseudonymous
help requests, contributions and feedback via plain-text mail to:


The mail submission port (587) is open to those behind firewalls
and allows access via Tor and anonymous remailers.
Archives are accessible via: http://bogomips.org/unicorn-public/
and mirrored to various other places, so you do not need to use
a valid address when posting.

Finally, rest assured the core design of unicorn will never change.
It will never use new-fangled things like threads, kqueue or epoll;
but will always remain a preforking server serving one client

[1] http://mid.gmane.org/20090211230457.GB22926@dcvr.yhbt.net
[2] this would've been like, totally gnarly in the 80s!