[ANN] unicorn 3.6.0 - HTTP server for fast clients and Unix

[Eric Wong]

Unicorn is an HTTP server for Rack applications designed to only serve
fast clients on low-latency, high-bandwidth connections and take
advantage of features in Unix/Unix-like kernels. Slow clients should
only be served by placing a reverse proxy capable of fully buffering
both the the request and response in between Unicorn and slow clients.

* http://unicorn.bogomips.org/
* (e-mail address removed)
* git://bogomips.org/unicorn.git

Changes: small fixes, PRNG workarounds

Mainly small fixes, improvements, and workarounds for fork() issues
with pseudo-random number generators shipped with Ruby (Kernel#rand,
OpenSSL::Random (used by SecureRandom and also by Rails).

The PRNG issues are documented in depth here (and links to Ruby Redmine):

http://bogomips.org/unicorn.git/commit?id=1107ede7
http://bogomips.org/unicorn.git/commit?id=b3241621

If you're too lazy to upgrade, you can just do this in your after_fork
hooks:

after_fork do |server,worker|
tmp = srand
OpenSSL::Random.seed(tmp.to_s) if defined?(OpenSSL::Random)
end

There are also small log reopening (SIGUSR1) improvements:

* relative paths may also be reopened, there's a small chance this
will break with a handful of setups, but unlikely. This should
make configuration easier especially since the "working_directory"
configurator directive exists. Brought up by Matthew Kocher:
http://thread.gmane.org/gmane.comp.lang.ruby.unicorn.general/900

* workers will just die (and restart) if log reopening fails for
any reason (including user error). This is to workaround the issue
reported by Emmanuel Gomez:
http://thread.gmane.org/gmane.comp.lang.ruby.unicorn.general/906

 

[Eric Wong]

If you're too lazy to upgrade, you can just do this in your after_fork
hooks:

after_fork do |server,worker|
tmp = srand
OpenSSL::Random.seed(tmp.to_s) if defined?(OpenSSL::Random)
end

That was broken and made the problem worse, do this instead (or upgrade
to 3.6.1):

after_fork do |server,worker|
srand
OpenSSL::Random.seed(rand.to_s) if defined?(OpenSSL::Random)
end

This is why ruby-core should fix these problems because application
authors like me are too clumsy to be trusted