Three instruments for composing an Agile architecture
TL;DR
- Organize, customise, scrutinize, repeat
- Organize: Get resuable parts, Modular characteristics, component interactions
- Customise: Production variations techniques, Instance attributes, Startup Variations Examples
- Scrutinize: Monitor growth
Full Version
Overreacting to changes leads to:
- Duplication
- Ambibuous interfaces
- Inflexible
- Disorganized
- Tight coupling
What is not Software architecture:
- Component design
- System design
- Component selction
But it makes the above easier.
Agile software architecture: How?
1- Organize
Function follows form:
- Organize for modularity
- Modularity facilitates evolution
- Evolution over reinvention
Get reusable parts
- Components specification
- Interface profiles
- Protocols
- General scenarios
System specific parts (not general), that will change when moving systems
- Startup, Shutdown
- Monitoring, Logging, Analytics
- Error Handling
Modular characteristics:
- Cohesive functionality
- Precise interfaces
- Limited knowledge of servers
- No knowledge of clients
Component interfactions:
- Strongly typed interfaces. The stronger the better.
- Task protocol (session, broadcast, subscription).
- Preconditions
2- Customize
Making the most of your software asset. One agile archecture that give us:
- Many environments
- Many technologies
- Many designs
Production variations techniques
- Conditional compilation
- make files
- code generation
Instance attributes
- Min and max values
- Physical sizes
- Environment constraints
Startup Variations Examples
- Robots
- Sleep management system
- Self driving vehicles
Slides: http://conferences.oreilly.com/software-architecture/engineering-business-ca/public/schedule/proceedings
3- Scrutinize (examine and inspect thoroughly)
Monitor growth
- Creeping component complexity
- Interdependent knowledge
- Over specialization
- Subject matter leaking
Ways to Scrutinize:
- Inspect: documentation, tests, construction, defects, requirements
- Reuse: UTs, drivers, simulators, vary environment
- Measure: changes, multiple owners, growth, defects
Organize, customise, scrutinize. REPEAT
The only thing that never changes is that everything changes.
