Reliable Architecture Ved Henrik Bærbak Christensen Reflective Architectures

1. ReliableArchitectureVed Henrik Bærbak ChristensenReflective Architectures Emne: reflectivearchitectureoverview 11 december 2009

2. Seminar Notes Reflectivearchitecture Generelt reflection: Arkitekturen har forståelse for sig selv Garlan: Adaptor laget til systemet skal bare ændres, hvis den samme style anvendes Gjerluf: Nævner ikke styles, fordi H-graps er en design style i sig selv herunder programmeringsmodel. Denne kan måske ikke anvendes til alle problemdomæner

3. Opgave Beskrivelse • The Garlan et al. paper describes a way to increase dependability by architectural means. Outline the requirements on the system in order for their proposal to work. • Outline the elements of their Architectural Model and how they define Architectural Style. • Fig 1. is a rich picture outlining their adaptation framework. Express instaed using a component-connector view as well as a deployment view as defined by Christensen et al. • Explain what Adapation Operators and Repair Strategies are and how they can be used to adapt the architecture. Why are they linked to architectural style? • Describe the monitoring/gauge system. How could such a system be implemented? • Relate the approach of Garlan et al. to • Autonomic computing: what aspects of self-* are their approach addressing? • Sommerville's definition of dependeability. What aspects is in focus? Could other aspects also be addressed by their approach? • Discuss whether their approach is feasible even without the use of their research tools, like Acme, Armani, etc. • Gjerlufsen et al. describe a radical different approach to architectural reflection. Describe the central ideas of the approach, and how they support architectural reflection. • Contrast and discuss Figure 1. of Gjerlufsen with the approach outlined by Garlan. • Outline the set design objectives for the H-map programming model, as well as what the software design "should do". • Garlan et al. discuss in terms of Architectural Style. How does Gjerlufsen et al. never discuss the concept of a style? • Discuss how the H-map approach may support "reliable architectures". Use the concepts of Sommerville, Luy, and others to discuss the approach's applicability. • Contrast and discuss the H-map approach to autonomic computing. • Contrast both approaches to the concepts of virtualization and debugging.

4. Gruppe præsentation på seminar Introduktion: • Forbedre system pålidelighed • Selv reparende systemer afgøre hvornår en handling er påkrævet i form af en adaptation • Selfreparende systemer tidligere expection eller RPC timout baseret og triggere • Ulemper: har svært ved at fange reduction af performance, tranisiente fejl • Ny tilgang : arkitektur modeller • Global perspektiv af system til identifikation af problemer • Arkitektur style som en runtime entitet der monitorer systemet og detekterer afviglser • Arkitektur er koblet med system kontruktion • Runtime model af systemet • Basis for system reparation

5. Arkitektur style • Komponent typer og deres relationer og constraints • Arkitektur adaption framework steps • Eksekverings system • Monitoringsmekanisker – runtime opførsel • Arkitektur model • Analyser • Reparations handler (adpat arkitektur) • Arkitektur til system translator til runtime handler

6. style • Hvilke properties overvåges • Constraints • Hvad der sker når constraints brydes • Hvordan sker reparation

7. Arkitektur stype (filter s.68) • Typer, komponenter, interfaces, connectors og properties • Graf • Hvis man overholder style supporteres: analyse, genbrug, kodegeneration og evolution

8. 1. Monitorering • Gauges er model specifikke • Konvertere fra lowlevel observations til properties og mere abstrakte repræsentationer

9. 2. Repair