This scenario shows a single repository database and content store, and two Tomcat nodes/web servers on two separate machines accessing the content simultaneously. The configuration does not guard against the content store or database failure, but allows multiple servers to share the web load, and provides redundancy in case of a server failure. Each server has local indexes (in the local content store).
This is the simplest cluster to set up and is ideal for small-scale installations. A cluster consisting of two or more machines working together provides a higher level of availability, reliability, and scalability than can be obtained from a single node.