Setting up the mongrel cluster
Install the required gems:
gem install mongrel mongrel_cluster daemons
Configure the mongrel cluster: this will start 3 instances of mongrel on the ports 8000, 8001, 8002
cd /your/rails/app
mongrel_rails cluster::configure -e production -p 8000 -N 3 -c /your/rails/app
Start it
mongrel_rails cluster::start
Setup the load balancer