unicorn.rb

# More Info here: http://unicorn.bogomips.org/Unicorn/OobGC.html
# require 'unicorn/oob_gc'
# GC every two requests that hit /expensive/foo or /more_expensive/foo
# in your app.  By default, this will GC once every 5 requests
# for all endpoints in your app
# Example:
#  use Unicorn::OobGC, 2, %r{\A/(?:admin/work_items/ast|admin/work_items/lp)}

# Use at least one worker per core if you're on a dedicated server,
# more will usually help for _short_ waits on databases/caches.
worker_processes Integer(ENV['UNICORN_WORKERS'] || 2)

# nuke workers after 45 seconds instead of 60 seconds (the default)
timeout Integer(ENV['UNICORN_TIMEOUT'] || 25)

# https://gist.github.com/apangeajwrubel/4953849
listen ENV['PORT'], backlog: Integer(ENV['UNICORN_BACKLOG'] || 200)

# Taken liberally from http://unicorn.bogomips.org/examples/unicorn.conf.rb
# -jodell
#
# combine Ruby 2.0.0dev or REE with "preload_app true" for memory savings
# http://rubyenterpriseedition.com/faq.html#adapt_apps_for_cow
preload_app true
GC.respond_to?(:copy_on_write_friendly=) and
  GC.copy_on_write_friendly = true

before_fork do |server, worker|
  # the following is highly recomended for Rails + "preload_app true"
  # as there's no need for the master process to hold a connection
  defined?(ActiveRecord::Base) and
    ActiveRecord::Base.connection.disconnect!

  # The following is only recommended for memory/DB-constrained
  # installations.  It is not needed if your system can house
  # twice as many worker_processes as you have configured.
  #
  # # This allows a new master process to incrementally
  # # phase out the old master process with SIGTTOU to avoid a
  # # thundering herd (especially in the "preload_app false" case)
  # # when doing a transparent upgrade.  The last worker spawned
  # # will then kill off the old master process with a SIGQUIT.
  # old_pid = "#{server.config[:pid]}.oldbin"
  # if old_pid != server.pid
  #   begin
  #     sig = (worker.nr + 1) >= server.worker_processes ? :QUIT : :TTOU
  #     Process.kill(sig, File.read(old_pid).to_i)
  #   rescue Errno::ENOENT, Errno::ESRCH
  #   end
  # end
  #
  # Throttle the master from forking too quickly by sleeping.  Due
  # to the implementation of standard Unix signal handlers, this
  # helps (but does not completely) prevent identical, repeated signals
  # from being lost when the receiving process is busy.
  # sleep 1
end

after_fork do |server, worker|
  # per-process listener ports for debugging/admin/migrations
  # addr = "127.0.0.1:#{9293 + worker.nr}"
  # server.listen(addr, :tries => -1, :delay => 5, :tcp_nopush => true)

  # the following is *required* for Rails + "preload_app true",
  defined?(ActiveRecord::Base) and
    ActiveRecord::Base.establish_connection

  # if preload_app is true, then you may also want to check and
  # restart any other shared sockets/descriptors such as Memcached,
  # and Redis.  TokyoCabinet file handles are safe to reuse
  # between any number of forked children (assuming your kernel
  # correctly implements pread()/pwrite() system calls)
end