unicorn.rb

# 4 workers is enough for our app
worker_processes 4

# App location
@app = "/var/rails/myapp/current"

# Listen on fs socket for better performance
listen "#{@app}/tmp/sockets/unicorn.sock", :backlog => 64

# Nuke workers after 30 seconds instead of 60 seconds (the default)
timeout 30

# App PID
pid "#{@app}/tmp/pids/unicorn.pid"

# By default, the Unicorn logger will write to stderr.
# Additionally, some applications/frameworks log to stderr or stdout,
# so prevent them from going to /dev/null when daemonized here:
stderr_path "#{@app}/log/unicorn.stderr.log"
stdout_path "#{@app}/log/unicorn.stdout.log"

# To save some memory and improve performance
preload_app true
GC.respond_to?(:copy_on_write_friendly=) and
  GC.copy_on_write_friendly = true

# Force the bundler gemfile environment variable to 
# reference the capistrano "current" symlink
before_exec do |_|
  ENV["BUNDLE_GEMFILE"] = File.join(@app, 'Gemfile')
end

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!
end

after_fork do |server, worker|
  # the following is *required* for Rails + "preload_app true",
  defined?(ActiveRecord::Base) and
    ActiveRecord::Base.establish_connection
end