FAQ 9.01 Is error handling a major source of fundamental mistakes?

Yes.

Unfortunately, error handling is usually not considered during the design process in most systems, and instead it is allowed to evolve chaotically and in an ad hoc manner. Part of this is the old-dog-new-trick problem: many programmers' instincts about error handling are based on outdated technology, which tends to lead them in the wrong direction. The purpose of this chapter is to present a sound strategy for modern error handling.

A software application's error-handling strategy must be designed as carefully as the rest of the system. Without a careful design, error handling will be applied inconsistently and will create more problems than it solves. Typically, half of a system's code is dedicated to handling errors in one way or another, and systems that attempt to survive faults, as opposed to simply crashing, have even more to gain from good error-handling strategies.