We have introduced a fairly formal approach to assessing and choosing a high availability solution for your applications. In reality, most folks who are attempting to do this Phase 0 HA assessment are really retrofitting their existing application for high availability. That's okay, since this Phase 0 assessment directly supports the retrofitting process. The key to success is doing as complete a job as you can on the assessment and using some of your best folks to do it. They will interpret the technology and the business needs with the most accuracy. You have so much riding on the proper assessment (potentially your company's existence). If you cannot free up your best folks to do this Phase 0 assessment, then go out and get some professionals that do this every day to do this for you. The relative small cost of this short effort will be retrieved very quickly. It is no small task to understand an application's HA requirement, time to recovery, tolerance of recovery, data resiliency, application resiliency, performance/scalability, and the costs of downtime (loss). Then, you must take this information, and couple it with your hardware/software configurations, several Microsoft-based technology offerings, and your allowable upgrade budget. But, the cost of not doing this will have a much greater impact, and if you are going to move to a high availability solution, getting the right one in place to start with will save tons of time and money in and of itself (and potentially your job).
Chapters 4 through 8 will describe the Microsoft solutions that can comprise a high availability solution (or component) and show you exactly how to implement them. This is intended to be more like a cookbook approach that will take you through the complete setup of something such as MSCS, SQL clustering, log shipping, data replication, or even distributed transaction processing. So, hold on to your hat, here we go.