Use Puma application server

- https://devcenter.heroku.com/articles/deploying-rails-applications-with-the-puma-web-server

Gemfile

@@ -28,6 +28,8 @@ gem 'rollbar', '~> 2.5.0'
 gem 'gcm'
 gem 'newrelic_rpm'
 
+gem 'puma'
+gem "rack-timeout"
 # Use ActiveModel has_secure_password
 # gem 'bcrypt', '~> 3.1.7'
 

Gemfile.lock

@@ -141,9 +141,11 @@ GEM
     pg (0.18.2)
     polyamorous (1.2.0)
       activerecord (>= 3.0)
+    puma (2.16.0)
     rack (1.6.4)
     rack-test (0.6.3)
       rack (>= 1.0)
+    rack-timeout (0.3.2)
     rails (4.2.4)
       actionmailer (= 4.2.4)
       actionpack (= 4.2.4)
@@ -259,6 +261,8 @@ DEPENDENCIES
   jquery-rails
   newrelic_rpm
   pg
+  puma
+  rack-timeout
   rails (= 4.2.4)
   rollbar (~> 2.5.0)
   rspec-rails
@@ -272,4 +276,4 @@ DEPENDENCIES
   web-console (~> 2.0)
 
 BUNDLED WITH
-   1.10.6
+   1.11.2

Procfile

@@ -0,0 +1 @@
+web: bundle exec puma -C config/puma.rb

config/initializers/timeout.rb

@@ -0,0 +1 @@
+Rack::Timeout.timeout = 20  # seconds

config/puma.rb

@@ -0,0 +1,23 @@
+#Please read the following before making any changes
+#1. https://devcenter.heroku.com/articles/deploying-rails-applications-with-the-puma-web-server
+#2. https://devcenter.heroku.com/articles/concurrency-and-database-connections#threaded-servers
+
+workers Integer(ENV['WEB_CONCURRENCY'] || 2)
+threads_count = Integer(ENV['MAX_THREADS'] || 1)
+threads threads_count, threads_count
+
+preload_app!
+
+rackup      DefaultRackup
+port        ENV['PORT']     || 3000
+environment ENV['RACK_ENV'] || 'development'
+
+on_worker_boot do
+  # Valid on Rails up to 4.1 the initializer method of setting `pool` size
+  ActiveSupport.on_load(:active_record) do
+    config = ActiveRecord::Base.configurations[Rails.env] ||
+                Rails.application.config.database_configuration[Rails.env]
+    config['pool'] = ENV['DB_POOL'] || 5
+    ActiveRecord::Base.establish_connection(config)
+  end
+end