Design Requirements for Geographically Dispersed Clusters

Applies To: Windows Server 2003, Windows Server 2003 R2, Windows Server 2003 with SP1, Windows Server 2003 with SP2

Although there are many requirements in setting up a geographically dispersed cluster, at the most fundamental level your design has to meet two requirements:

• Both sites must have independent copies of the same data. The goal of a geographically dispersed cluster is that if one site is lost, such as from a natural disaster, the applications can continue running at the other site. For read-only data, the challenge is relatively simple: the data can be cloned, and one instance can run at each site. However, in a typical stateful application, in which data is updated frequently, you must consider how changes made to the data at one site are replicated to the other site.

• When there is a failure at one site, the application must restart at the other site. Even if the application data is replicated to all sites, you need to know how the application is restarted at an alternate site when the site that was running the application fails.

Important

• The hardware and software configuration of a geographically dispersed cluster must be certified and listed in the Windows Server Catalog. Also, be sure to involve your hardware manufacturer in your design decisions. Frequently, third-party software and drivers are required for geographically dispersed clusters to function correctly. Microsoft Product Support Services might not be aware of how these components interact with Windows Clustering. For more information about hardware and software configurations, see the Windows Server Catalog link on the Web Resources page at https://www.microsoft.com/windows/reskits/webresources.