Head First Software Architecture: A Learner's Guide to Architectural Thinking

Cover
Title Page
Copyright
About the Authors
Table of Contents
Intro
Chapter 1: Software Architecture Demystified
	Building your understanding of software architecture
	Building plans and software architecture
	The dimensions of software architecture
	Puzzling out the dimensions
	The first dimension: Architectural characteristics
	The second dimension: Architectural decisions
	The third dimension: Logical components
	The fourth dimension: Architectural styles
	A design perspective
	An architectural perspective
	The spectrum between architecture and design
	Where along the spectrum does your decision fall?
	Strategic versus tactical
	High versus low levels of effort
	Significant versus less-significant trade-offs
	Putting it all together
	You made it!
Chapter 2: Architectural Characteristics
	Causing Lafter
	What are architectural characteristics?
	Defining architectural characteristics
	Characteristics are nondomain design considerations
	Characteristics influence architectural structure
	Limit characteristics to prevent overengineering
	Consider explicit and implicit capabilities
	The International Zoo of “-ilities”
	Process architectural characteristics
	Structural architectural characteristics
	Operational architectural characteristics
	Cross-cutting architectural characteristics
	Sourcing architectural characteristics from the problem domain
	Sourcing architectural characteristics from environmental awareness
	Sourcing architectural characteristics from holistic domain knowledge
	Composite architectural characteristics
	Priorities are contextual
	Lost in translation
	Architectural characteristics and logical components
	Balancing domain considerations and architectural characteristics
	Limiting architectural characteristics
Chapter 3: The Two Laws of Software Architecture
	It starts with a sneaker app
	What do we know so far?
	Communicating with downstream services
	Analyzing trade-offs
	Trade-off analysis: Queue edition
	Trade-off analysis: Topic edition
	The first law of software architecture
	It always comes back to trade-offs
	Making an architectural decision
	What else makes a decision architectural?
	The second law of software architecture
	Architectural decision records (ADRs)
	Writing ADRs: Getting the title right
	Writing ADRs: What’s your status?
	Writing ADRs: Establishing the context
	Writing ADRs: Communicating the decision
	Writing ADRs: Considering the consequences
	Writing ADRs: Ensuring governance
	Writing ADRs: Closing notes
	The benefits of ADRs
	Two Many Sneakers is a success
Chapter 4: Logical Components
	Logical components revisited
	Name that component
	Adventurous Auctions goes online
	Logical versus physical architecture
	Creating a logical architecture
	Step 1: Identifying initial core components
	Workflow approach
	Actor/action approach
	The entity trap
	Step 2: Assign requirements
	Step 3: Analyze roles and responsibilities
	Sticking to cohesion
	Step 4: Analyze characteristics
	The Bid Capture component
	Component coupling
	Afferent coupling
	Efferent coupling
	Measuring coupling
	A tightly coupled system
	Applying the Law of Demeter
	A balancing act
	Some final words about components
Chapter 5: Categorization and Philosophies
	There are lots of architectural styles
	The world of architectural styles
	Partitioning: Technical versus domain
	Deployment model: Monolithic versus distributed
	Monolithic deployment models: The pros
	Monolithic: The cons
	Distributed deployment models: The pros
	Distributed deployment models: The cons
	And that’s a wrap!
Chapter 6: Layered Architecture
	Naan & Pop: Gathering requirements
	Design patterns redux
	Layering MVC
	Layering it on
	Translating layers into code
	Domains, components, and layers
	Drivers for layered architecture
	Layers, meet the real world: Physical architectures
	Physical architecture trade-offs
	One final caveat about domain changes
	Layered architecture superpowers
	Layered architecture kryptonite
	Layered architecture star ratings
	Wrapping it up
Chapter 7: Driven by the Domain
	Modular monolith?
	Domain pains changes
	Why modular monoliths?
	Show me the code!
	Keeping modules modular
	Taking modularity all the way to the database
	Beware of joins
	Modular monolith superpowers
	Modular monolith kryptonite
	Modular monolith star ratings
	Naan & Pop is delivering pizza!
Chapter 8: Microkernel Architecture
	The benefits of Going Green
	The two parts of microkernel architectures
	The spectrum of “microkern-ality”
	Device assessment service core
	Encapsulated versus distributed plugins
	Plugin communication
	Cubicle conversation
	Plugin contracts
	Going Green goes green
	Microkernel superpowers
	Microkernel kryptonite
	Microkernel star ratings
	Wrapping it up
Chapter 9: Do It Yourself
	Making travel easier
	TripEZ’s user workflow
	Planning the architecture
	The architects’ roadmap
	Step 1: Identify architectural characteristics
	Step 2: Identify logical components
	Step 3: Choose an architectural style
	Step 4: Document your decision
	Step 5: Diagram your architecture
	There are no right (or wrong) answers
Chapter 10: Microservices Architecture
	Are you feeling okay?
	What’s a microservice?
	It’s my data, not yours
	How micro is “micro”?
	Granularity disintegrators
	Why should you make microservices smaller?
	Granularity integrators
	Why should you make microservices bigger?
	It’s all about balance
	Sharing functionality
	Code reuse with a shared service
	Code reuse with a shared library
	Managing workflows
	Orchestration: Conducting microservices
	Choreography: Let’s dance
	Microservices architecture superpowers
	Microservices architecture kryptonite
	Microservices star ratings
	Wrapping it up
Chapter 11: Event-Driven Architecture
	Too slow
	Speeding things up
	Der Nile flows faster than ever
	What is an event?
	Events versus messages
	Initiating and derived events
	Is anyone listening?
	Asynchronous communication
	Fire-and-forget
	Asynchronous for the win
	Synchronous for the win
	Database topologies
	Monolithic database
	Domain-partitioned databases
	Database-per-service
	EDA versus microservices
	Hybrids: Event-driven microservices
	Event-driven architecture superpowers
	Event-driven architecture kryptonite
	Event-driven architecture star ratings
	Putting it all together
	Wrapping up
Chapter 12: Testing Your Knowledge
	Welcome to Make the Grade
	Student testing workflow
	Planning the architecture
	The architects’ roadmap
	Step 1: Identify architectural characteristics
	Step 2: Identify logical components
	Step 3: Choose an architectural style
	Step 4: Document your decision
	Step 5: Diagram your architecture
	There are no right (or wrong) answers!
Appendix: Leftovers
	#1 The coding architect
	#2 Expectations for architects
	#3 The soft skills of architecture
	#4 Diagramming techniques
	#5 Knowledge depth versus breadth
	#6 Practicing architecture with katas
Index