Reliability: It's a term that you hear quite often today as the price of devices plummets and the quality of the components used to create them becomes an issue. Most businesses today run 24/7, so reliability is on the tip of many administrators' tongues. Reliability should be part of your vocabulary, too. Many developers wrongly associate reliability only with hardware — reliability is a software issue as well. As described in this book, reliability is a measure of how long something will work as intended without loss to an organization. The term loss requires a little explanation. You can probably define what loss means specifically to your organization, but any definition of loss should include:
Lack of user access
Data corruption or outright loss
Restrictions on software use or a complete crash
Configuration or compatibility issues
Financial considerations (such as lost customer sales)
Designing an application for reliability means keeping loss of all types at bay. In general, you ensure that all the components used to create the application are reliable and that the application structure itself supports reliable operation. You must also place constraints on user activity that would tend to reduce application reliability. In many cases, application reliability requires that you monitor the application for aberrant activities from any source, including the user.
Application reliability requires that you become invasive in ...