The goal of all availability process owners is to maximize the uptime of the various online systems for which they're responsiblein essence, to make them completely fault-tolerant. Constraints inside and outside the IT environment make this challenge close to impossible. Budget limitations, component failures, faulty code, human error, flawed design, natural disasters, and unforeseen business shifts such as mergers, downturns, and political changes are just some of the factors working against that elusive goal of 100% availabilitythe ultimate expression of high availability.
But several approaches can maximize availability without breaking the budget bank. Each of these approaches start with the same letter, so we refer to them as the seven R's of high availability: