Posts Tagged ‘Gartner’
[DevoxxBE2012] Architecture All the Way Down
Kirk Knoernschild, a software developer passionate about modular systems and author of “Java Application Architecture,” explored the pervasive nature of architecture in software. Kirk, drawing from his book on OSGi patterns, challenged traditional views, arguing architecture permeates all levels—from high-level designs to code.
He invoked the “turtles all the way down” anecdote to illustrate architecture’s recursive essence: decisions at every layer impact flexibility. Kirk critiqued ivory-tower approaches, advocating collaborative, iterative practices aligning business and technology.
Paradoxically, architecture aims for change resistance yet adaptability. Temporal dimensions—decisions’ longevity—affect modularity: stable elements form foundations, volatile ones remain flexible.
Kirk linked SOA’s service granularity to modularity, noting services as deployable units fostering reuse. He emphasized patterns ensuring evolvability without rigidity.
Demystifying Architectural Paradoxes
Kirk elaborated on architecture’s dual goals: stability against volatility. He used examples where over-design stifles agility, advocating minimal upfront planning with evolutionary refinement.
Temporal hierarchies classify decisions by change frequency: strategic (years), tactical (months), operational (days). This guides layering: stable cores support variable extensions.
Granularity and Modularity Principles
Discussing granularity, Kirk warned against extremes: monolithic systems hinder reuse; overly fine-grained increase complexity. Patterns like base and dependency injection promote loose coupling.
He showcased OSGi’s runtime modularity, enforcing boundaries via exports/imports, preventing spaghetti code.
Linking Design to Temporal Decisions
Kirk connected design principles—SOLID—to temporal aspects: single responsibility minimizes change impact; open-closed enables extension without modification.
He illustrated with code: classes as small modules, packages as mid-level, OSGi bundles as deployable.
SOA and Modular Synergies
In SOA, services mirror modules: autonomous, composable. Kirk advocated aligning service boundaries with business domains, using modularity patterns for internal structure.
He critiqued layered architectures fostering silos, preferring vertical slices for cohesion.
Practical Implementation and Tools
Kirk recommended modular frameworks like OSGi or Jigsaw, but stressed design paradigms over tools. Patterns catalog aids designing evolvable systems.
He concluded: multiple communication levels—classes to services—enhance understanding, urging focus on modularity for adaptive software.
Kirk’s insights reframed architecture as holistic, from code to enterprise, essential for enduring systems.