Software Architecture: The Hard Parts

Inhaltsverzeichnis des Buches

• Preface
• Conventions Used in This Book
• Using Code Examples
• O’Reilly Online Learning
• How to Contact Us
• Acknowledgments
• Acknowledgments from Mark Richards
• Acknowledgments from Neal Ford
• Acknowledgments from Pramod Sadalage
• Acknowledgments from Zhamak Dehghani
• 1. What Happens When There Are No “Best Practices”?
• Why “The Hard Parts”?
• Giving Timeless Advice About Software Architecture
• The Importance of Data in Architecture
• Architectural Decision Records
• Architecture Fitness Functions
• Using Fitness Functions
• Architecture Versus Design: Keeping Definitions Simple
• Introducing the Sysops Squad Saga
• Nonticketing Workflow
• Ticketing Workflow
• A Bad Scenario
• Sysops Squad Architectural Components
• Sysops Squad Data Model
• I. Pulling Things Apart
• 2. Discerning Coupling in Software Architecture
• Architecture (Quantum | Quanta)
• Independently Deployable
• High Functional Cohesion
• High Static Coupling
• Dynamic Quantum Coupling
• Sysops Squad Saga: Understanding Quanta
• 3. Architectural Modularity
• Modularity Drivers
• Maintainability
• Testability
• Deployability
• Scalability
• Availability/Fault Tolerance
• Sysops Squad Saga: Creating a Business Case
• 4. Architectural Decomposition
• Is the Codebase Decomposable?
• Afferent and Efferent Coupling
• Abstractness and Instability
• Distance from the Main Sequence
• Component-Based Decomposition
• Tactical Forking
• Trade-Offs
• Sysops Squad Saga: Choosing a Decomposition Approach
• 5. Component-Based Decomposition Patterns
• Identify and Size Components Pattern
• Pattern Description
• Fitness Functions for Governance
• Sysops Squad Saga: Sizing Components
• Gather Common Domain Components Pattern
• Pattern Description
• Fitness Functions for Governance
• Sysops Squad Saga: Gathering Common Components
• Flatten Components Pattern
• Pattern Description
• Fitness Functions for Governance
• Sysops Squad Saga: Flattening Components
• Determine Component Dependencies Pattern
• Pattern Description
• Fitness Functions for Governance
• Sysops Squad Saga: Identifying Component Dependencies
• Create Component Domains Pattern
• Pattern Description
• Fitness Functions for Governance
• Sysops Squad Saga: Creating Component Domains
• Create Domain Services Pattern
• Pattern Description
• Fitness Functions for Governance
• Sysops Squad Saga: Creating Domain Services
• Summary
• 6. Pulling Apart Operational Data
• Data Decomposition Drivers
• Data Disintegrators
• Data Integrators
• Sysops Squad Saga: Justifying Database Decomposition
• Decomposing Monolithic Data
• Step 1: Analyze Database and Create Data Domains
• Step 2: Assign Tables to Data Domains
• Step 3: Separate Database Connections to Data Domains
• Step 4: Move Schemas to Separate Database Servers
• Step 5: Switch Over to Independent Database Servers
• Selecting a Database Type
• Relational Databases
• Key-Value Databases
• Document Databases
• Column Family Databases
• Graph Databases
• NewSQL Databases
• Cloud Native Databases
• Time-Series Databases
• Sysops Squad Saga: Polyglot Databases
• 7. Service Granularity
• Granularity Disintegrators
• Service Scope and Function
• Code Volatility
• Scalability and Throughput
• Fault Tolerance
• Security
• Extensibility
• Granularity Integrators
• Database Transactions
• Workflow and Choreography
• Shared Code
• Data Relationships
• Finding the Right Balance
• Sysops Squad Saga: Ticket Assignment Granularity
• Sysops Squad Saga: Customer Registration Granularity
• II. Putting Things Back Together
• 8. Reuse Patterns
• Code Replication
• When to Use
• Shared Library
• Dependency Management and Change Control
• Versioning Strategies
• When To Use
• Shared Service
• Change Risk
• Performance
• Scalability
• Fault Tolerance
• When to Use
• Sidecars and Service Mesh
• When to Use
• Sysops Squad Saga: Common Infrastructure Logic
• Code Reuse: When Does It Add Value?
• Reuse via Platforms
• Sysops Squad Saga: Shared Domain Functionality
• 9. Data Ownership and Distributed Transactions
• Assigning Data Ownership
• Single Ownership Scenario
• Common Ownership Scenario
• Joint Ownership Scenario
• Table Split Technique
• Data Domain Technique
• Delegate Technique
• Service Consolidation Technique
• Data Ownership Summary
• Distributed Transactions
• Eventual Consistency Patterns
• Background Synchronization Pattern
• Orchestrated Request-Based Pattern
• Event-Based Pattern
• Sysops Squad Saga: Data Ownership for Ticket Processing
• 10. Distributed Data Access
• Interservice Communication Pattern
• Column Schema Replication Pattern
• Replicated Caching Pattern
• Data Domain Pattern
• Sysops Squad Saga: Data Access for Ticket Assignment
• 11. Managing Distributed Workflows
• Orchestration Communication Style
• Choreography Communication Style
• Workflow State Management
• Trade-Offs Between Orchestration and Choreography
• State Owner and Coupling
• Sysops Squad Saga: Managing Workflows
• 12. Transactional Sagas
• Transactional Saga Patterns
• Epic Saga(sao) Pattern
• Phone Tag Saga(sac) Pattern
• Fairy Tale Saga(seo) Pattern
• Time Travel Saga(sec) Pattern
• Fantasy Fiction Saga(aao) Pattern
• Horror Story(aac) Pattern
• Parallel Saga(aeo) Pattern
• Anthology Saga(aec) Pattern
• State Management and Eventual Consistency
• Saga State Machines
• Techniques for Managing Sagas
• Sysops Squad Saga: Atomic Transactions and Compensating Updates
• 13. Contracts
• Strict Versus Loose Contracts
• Trade-Offs Between Strict and Loose Contracts
• Contracts in Microservices
• Stamp Coupling
• Over-Coupling via Stamp Coupling
• Bandwidth
• Stamp Coupling for Workflow Management
• Sysops Squad Saga: Managing Ticketing Contracts
• 14. Managing Analytical Data
• Previous Approaches
• The Data Warehouse
• The Data Lake
• The Data Mesh
• Definition of Data Mesh
• Data Product Quantum
• Data Mesh, Coupling, and Architecture Quantum
• When to Use Data Mesh
• Sysops Squad Saga: Data Mesh
• 15. Build Your Own Trade-Off Analysis
• Finding Entangled Dimensions
• Coupling
• Analyze Coupling Points
• Assess Trade-Offs
• Trade-Off Techniques
• Qualitative Versus Quantative Analysis
• MECE Lists
• The “Out-of-Context” Trap
• Model Relevant Domain Cases
• Prefer Bottom Line over Overwhelming Evidence
• Avoiding Snake Oil and Evangelism
• Sysops Squad Saga: Epilogue
• A. Concept and Term References
• B. Architecture Decision Record References
• C. Trade-Off References
• Index
• About the Authors