If you want to offer any IP-based service with automatic failover to provide high availability (HA), you can use heartbeat to create an HA cluster.
Heartbeat will run on two or more nodes and ensure that the IP address you chose to make highly available will switch to a working node, if one of them goes down. This way, you have a failover IP address, which is guaranteed to reach a running host, as long as there is one left.
Let's take a look at how to install heartbeat on your nodes and configure it with a failover IP address.
Make sure that you have two machines, named ha1 and ha2, up and running. You can use a Vagrantfile like this or use Chef Provisioning to set them up. You need to replace awo with a short name of your own Chef organization:
def define_node(config, node_name, ip_address=nil, the_recipe=nil)
config.vm.define node_name do |node|
node.vm.hostname = node_name.to_s
node.vm.network :private_network, ip...