Clustering is the focal point in the application servers. An application server is not only chosen because it provides developing tools to make the creation of Java client-server applications simpler. An application server can guarantee the data of the applications to be durable in the time, and mostly, they must not be loose.
The clustering technique is done to provide maximum security of the data. The data is present in a database. What happens if the database crushes and it is not recoverable? Clustering can resolve this problem.
A cluster is a set of nodes containing replicated data in a net. The number of nodes depends usually on the available machines and on the quantity of the use of the applications on the internet. The number can change from 2 nodes to 1000 nodes and more using the right clustering technique. If a node is destroyed, there must always be another...