Introduction to Architecture Session Marseilles September 1999 John

Introduction to Architecture Session Marseilles September 1999 John Harvey CERN / LHCb

Importance of Software Architecture q Booch : “Development of complex software systems should be architecture-driven” q Architecture specifications provide a blueprint for everyone to follow ã facilitate communication between developers ã developers know how to contribute their pieces q Architectures can be designed to accommodate new requirements or changes in technology ã adaptable - more resilient to change ã flexible and extensible - they must evolve in an incremental fashion q Implemented via frameworks that can be reused for different data processing applications ã ensure architecture is respected ã solve standard computing tasks once…. must do a lot and be configurable ã provide clean interface for end user - must be easy to understand use Introduction to Architecture Session, Marseilles, September 1999 Slide 2

Goals of Architecture Session q Raise awareness of the importance of firstly specifying the software architecture before building large software systems q Introduce the vocabulary explaining the meaning of commonly used terms q Introduce through examples common architectural patterns (styles) q Illustrate the important architectural features that have impact on quality q Introduce through examples architectures in use in HEP today q Illustrate the scope of the architecture ã conceptual view illustrating logical structure ã concrete view illustrating the physical structure (packaging, building releases, impact on performance…) q Exchange opinions on what constitutes a good architecture ã as our data processing needs are so similar a good architecture for one experiment should be applicable elsewhere q Identify important issues that need to be addressed and concrete actions that should be taken Introduction to Architecture Session, Marseilles, September 1999 Slide 3

The goals of the session are not to…. . q Solve technical issues q Choose the best technical solution q Scope does not cover very specific application domains such as the data acquisition system Introduction to Architecture Session, Marseilles, September 1999 Slide 4

Architecture Study Group q Setup end June 1999 as a technical forum to study the issue of software architecture. . q. . and to help prepare for this workshop q Membership : ã Alberto Aimar, John Apostolakis, Rene Brun, Dirk Duellmann, John Harvey, Vincenzo Innocente, Pere Mato, RD Schaffer, David Stickland, Lassi Tuura ã Christian Arnault, Federico Carminati, Fons Rademacker, Craig Tull, Pierre vande Vyvre q Met seven times during the summer - informal q Results of deliberations kept on a web site ã copies of slides and bibliography of relevant published material and web sites ã URL : http: //lhcb. cern. ch/computing/SWarch. WG/html/Default. htm q Interest to continue after the workshop ã come back to in the discussion Introduction to Architecture Session, Marseilles, September 1999 Slide 5