TechEmpower.FrameworkBenchmarks/rails/config/unicorn.rb

worker_processes 8
listen "/tmp/.sock", :backlog => 256

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