There are many reasons clusters are difficult to manage: the number of servers, their connecting components, the application managing them such as Microsofts’ Cluster Administrator, and the inherent problem that clusters are designed to failover to each other. In essence, they are specifically designed to react to the problem after it happens.
There is also a requirement that your applications are “cluster-aware.” A cluster solution is not so much of a product as a tool set. To have the cluster work, your applications must be written with the tools so the application has knowledge of the cluster solution built into it.
Now, lots of commercial software such as SQL-server, for example, is cluster aware, however, the cluster-aware version of such software often carries a much higher license fee.
According to Microsoft’s website, applications are capable of being cluster-aware if they use TCP/IP as a network protocol, maintains data in a configurable location, and supports transaction processing. Essentially, in order to use a cluster solution, you must first choose applications that is “cluster aware.”
As an alternative, the virtualization-ready ftServer requires no specialties of application, requires no workarounds, and is a simple, plug-in-and-go solution.