use unicorn over thin

Gemfile

@@ -15,8 +15,11 @@ gem 'pg'
 # for building JSON
 gem 'jbuilder', '~> 1.2'
 
-# ruby web server
-gem 'thin'
+# HTTP server for Rack applications
+gem 'unicorn'
+
+# without this in development webrick is used
+gem "unicorn-rails"
 
 # for authentication
 gem 'devise', '3.2.3'

Gemfile.lock

@@ -78,7 +78,6 @@ GEM
       coffee-script-source
       execjs
     coffee-script-source (1.8.0)
-    daemons (1.1.9)
     delayed_job (4.0.2)
       activesupport (>= 3.0, < 4.2)
     delayed_job_active_record (4.0.1)
@@ -100,7 +99,6 @@ GEM
     email_validator (1.4.0)
       activemodel
     erubis (2.7.0)
-    eventmachine (1.0.3)
     execjs (2.2.1)
     formtastic (2.3.0.rc3)
       actionpack (>= 3.0)
@@ -136,6 +134,7 @@ GEM
     kaminari (0.16.1)
       actionpack (>= 3.0.0)
       activesupport (>= 3.0.0)
+    kgio (2.9.2)
     mail (2.6.3)
       mime-types (>= 1.16, < 3)
     mime-types (2.4.3)
@@ -177,6 +176,7 @@ GEM
       activesupport (= 4.1.8)
       rake (>= 0.8.7)
       thor (>= 0.18.1, < 2.0)
+    raindrops (0.13.0)
     rake (10.3.2)
     ransack (1.2.3)
       actionpack (>= 3.0)
@@ -210,10 +210,6 @@ GEM
       actionpack (>= 3.0)
       activesupport (>= 3.0)
       sprockets (>= 2.8, < 4.0)
-    thin (1.6.2)
-      daemons (>= 1.0.9)
-      eventmachine (>= 1.0.0)
-      rack (>= 1.0.0)
     thor (0.19.1)
     thread_safe (0.3.4)
     tilt (1.4.1)
@@ -227,6 +223,13 @@ GEM
     uglifier (2.5.3)
       execjs (>= 0.3.0)
       json (>= 1.8.0)
+    unicorn (4.8.2)
+      kgio (~> 2.6)
+      rack
+      raindrops (~> 0.7)
+    unicorn-rails (2.2.0)
+      rack
+      unicorn
     warden (1.2.3)
       rack (>= 1.0)
 
@@ -258,6 +261,7 @@ DEPENDENCIES
   simplecov
   spring
   sprockets-rails (~> 2.0)
-  thin
   twitter-bootstrap-rails
   uglifier (>= 1.0.3)
+  unicorn
+  unicorn-rails

Procfile

@@ -0,0 +1,2 @@
+web: bundle exec unicorn -p $PORT -c ./config/unicorn.rb
+worker: bundle exec rake jobs:work

config/unicorn.rb

@@ -0,0 +1,27 @@
+# this template has been picked up from
+# https://devcenter.heroku.com/articles/rails-unicorn
+
+worker_processes Integer(ENV["WEB_CONCURRENCY"] || 2)
+
+# 30 seconds is the timeout for heroku. If it is not
+# deployed on heroku then it can be bumped up.
+timeout 30
+
+preload_app true
+
+before_fork do |server, worker|
+  Signal.trap 'TERM' do
+    puts 'Unicorn master intercepting TERM and sending myself QUIT instead'
+    Process.kill 'QUIT', Process.pid
+  end
+
+  defined?(ActiveRecord::Base) and ActiveRecord::Base.connection.disconnect!
+end
+
+after_fork do |server, worker|
+  Signal.trap 'TERM' do
+    puts 'Unicorn worker intercepting TERM and doing nothing. Wait for master to send QUIT'
+  end
+
+  defined?(ActiveRecord::Base) and ActiveRecord::Base.establish_connection
+end