The Art of Application Performance Testing, 2nd Edition

Chapter 1. Why Performance Test?

Faster than a speeding bullet . . .

Superman, Action Comics

Welcome! Before diving into the basics of performance testing, I want to use this first chapter to talk a little about what we mean by good and bad performance and why performance testing is such a vital part of the software development life cycle (SDLC). Non-performant (i.e., badly performing) applications generally don’t deliver their intended benefit to an organization; they create a net cost of time and money, and a loss of kudos from the application users, and therefore can’t be considered reliable assets. If a software application is not delivering its intended service in a performant and highly available manner, regardless of causation, this reflects badly on the architects, designers, coders, and testers (hopefully there were some!) involved in its gestation.

Performance testing continues to be the poor, neglected cousin of functional and operational acceptance testing (OAT), which are well understood and have a high maturity level in most business organizations. It is strange that companies continue to overlook the importance of performance testing, frequently deploying applications with little or no understanding of their performance, only to be beset with performance and scalability problems soon after the release. This mindset has changed little over the past 15 years, despite the best efforts of consultants like myself and the widely publicized failure of many high-profile ...