Apache Web Server: Applying Lessons from Physical Architecture to Enable Systems to Thrive

William T. Schiano David J. Yates Leslie J. Waguespack

Bentley University
Waltham, MA, USA
wschiano@bentley.edu

Bentley University
Waltham, MA, USA
dyates@bentley.edu

Bentley University
Waltham, MA, USA
lwaguespack@bentley.edu

Abstract — The Apache web server is one of the most successful software products in history. The architecture of Apache has been a primary driver of this success. To understand what has made Apache thrive, and to learn from its success, we turn to lessons gleaned from physical architecture. Christopher Alexander distilled architectural quality into fifteen properties, the combination of which determines whether the architecture will exhibit wholeness, or life. Waguespack has applied Alexander’s theory to articulate fifteen corresponding properties of modeling and information systems that determine whether an information system will have sufficient functionality and strength to thrive. We first explain Apache’s success over time through the application of these properties. We then explore how organizations can emulate this success in their own information systems by managing the portfolio of properties. Linking information systems properties to desirable business outcomes to create a synergy between design goals and business requirements is critical to success. For a system to serve the needs of a business, its design and implementation should not only accommodate, but facilitate change. We argue that facilitating change amplifies, not obviates, the need for great architecture. Applying the lessons from physical architecture to enable systems to thrive thus improves both system agility and business agility.

This paper appeared at ICDPP 2013, March 6–8, in Chiba, Japan. A brief overview of this paper is posted here.