A group is always stronger than individuals. The same is true in the world of servers. A group of servers combined by a design can offer benefits individual servers cannot. For starters, cluster servers offer increased reliability and high availability.
Cluster servers are capable of recovering from any kind of failure fast. They can recover from any failure in hardware, software, or the site. Cluster servers, thus, offer a high level of business continuity.
When one server fails for a reason, other servers take on its load. This ensures that downtimes are minimized. Thus, your applications are available most of the time.
When your servers form a cluster, they tend to accommodate your growing needs easily. You can add more servers to the cluster without much problem. Thus, clustering offers high scalability.
When it comes to maintenance, cluster servers offer an advantage. You know how difficult it is to maintain a single server. You need to shut it down for the maintenance period, making applications unavailable during that period. With cluster servers, however, you can shut down one server at a time, while others make sure your applications are always available.
Now, cluster servers are definitely lucrative but forming a cluster is not easy. There are many reasons not all organizations can go for server clustering. First, not all types of servers can be clustered. Second, not all kinds of applications are supported by cluster designs. Third, some cluster designs are extremely complicated to implement. Fourth, cluster designs are generally expensive. It is important that you make sure you understand your needs before you go into clustering.