Before you start creating clusters, you have to determine what type of GIS services you possess. This is done by properly planning and designing GIS services, analyzing their nature, and predicting what kind of resources are required, which you have already done back in Chapter 4, Planning and Designing GIS Services. Once you identify your GIS services, you can decide what kind of clusters you want to create. You might not require any clustering at all; however, sometimes you need to group your GIS servers by some factors. GIS services can be grouped by resources and computing power, where you put the most resourceful GIS servers into one cluster and your typical ones in another cluster.

You can group your servers by security level; you can assign high-profile and sensitive GIS services running on servers with tightened cyber and physical security to a dedicated cluster. Some even create clusters by networking area, where servers within the same area network and subnet...