Thin

http://code.macournoyer.com/thin/

http://articles.slicehost.com/2008/5/6/ubuntu-hardy-apache-rails-and-thin

Install

as root:

gem install thin
thin install
update-rc.d -f thin defaults  (to have thin restart on reboot)

Config File

put this into /etc/thin/myapp.yml:

--- 
pid: tmp/pids/thin.pid
address: 0.0.0.0
timeout: 30
wait: 30
port: 4810
log: log/thin.log
max_conns: 1024
require: []

max_persistent_conns: 512
#environment: development
environment: production
servers: 4
daemonize: true
chdir: /var/www/myapp

Use with Apache

Set up modules:

a2enmod proxy
a2enmod proxy_balancer
a2enmod proxy_http
a2enmod rewrite

The virtual host file should look something like this:

<VirtualHost *:80>
  ServerName myapp.com
  ServerAlias www.myapp.com
  LogLevel warn
  ErrorLog /var/log/apache2/myapp-error.log
  CustomLog /var/log/apache2/myapp-access.log combined

  DocumentRoot /var/www/myapp/public

  RewriteEngine On

  <Proxy balancer://thinservers>
    BalancerMember http://127.0.0.1:5000
    BalancerMember http://127.0.0.1:5001
    BalancerMember http://127.0.0.1:5002
  </Proxy>

  # Redirect all non-static requests to thin
  RewriteCond %{DOCUMENT_ROOT}/%{REQUEST_FILENAME} !-f
  RewriteRule ^/(.*)$ balancer://thinservers%{REQUEST_URI} [P,QSA,L]

  ProxyPass / balancer://thinservers/
  ProxyPassReverse / balancer://thinservers/
  ProxyPreserveHost on

  <Proxy *>
    Order deny,allow
    Allow from all
  </Proxy>

</VirtualHost>