Lesson189 - Architectural Quantum Tradeoffs

Summary

In this episode of 'Software Architecture Monday,' Mark Richards explores the concept of architectural quantum, a term that describes independently deployable artifacts with high functional cohesion and synchronous dynamic coupling. He revisits the idea of dynamic quantum entanglement and its implications for system dependencies. Using the 'sisp squad' as a case study, Richards illustrates the trade-offs involved in creating or separating architectural quanta, emphasizing the importance of balancing user experience with the benefits of modular, independently deployable system components.

Takeaways

• 👋 Introduction: Mark Richards starts the lesson on 'Software Architecture Monday' discussing the architectural quantum concept and trade-offs involved.
• 🧑‍🎨 Theme: The lesson focuses on the architectural quantum, a concept that Mark has previously touched upon in lesson 138, and its implications in system design.
• 🔍 Definition: An architectural quantum is an independently deployable artifact with high functional cohesion and synchronous dynamic coupling.
• 📚 Source: The concept is identified in 'Building Evolutionary Architectures' by Neil Ford, Rebecca Parsons, and Patrick Qua and further refined in 'Software Architecture: The Hard Parts'.
• 🛠️ Example: The SISP Squad, a trouble ticket system for electronics support plans, is used to illustrate the architectural quantum and its trade-offs.
• 🔄 Dynamic Quantum Entanglement: Systems can become unknowingly entangled, creating dependencies between them through both synchronous and asynchronous communication.
• 🔑 Key Insight: Architectural characteristics live at the quantum level, and understanding these can help in the partitioning of complex systems.
• ⚙️ Trade-offs: There are trade-offs between creating separate, independently deployable units of architecture and maintaining a cohesive user experience.
• 🔄 Dependency: Synchronous dynamic coupling can bind architectural quanta together, even if they are designed to be separate, due to shared resources like databases.
• 🛑 Solutions: One solution to entanglement is to create separate user interfaces and databases for different functionalities to ensure independence.
• 🤔 Consideration: The decision to separate or entangle architectural quanta depends on the importance of user experience versus the benefits of independent deployment and system characteristics.
• 📈 Conclusion: Mark emphasizes the importance of understanding the architectural quantum concept and its trade-offs in software architecture, as everything involves a trade-off.

Q & A

What is the main topic of the 189th lesson by Mark Richards in 'Software Architecture Monday'?

The main topic of the lesson is the architectural quantum concept and the trade-offs involved in using or forming architectural quanta.

What does Mark Richards wear when he discusses trade-offs as a core piece of the lesson?

Mark Richards wears his architecture shirt that says 'It Depends' when discussing trade-offs.

What is the concept of an 'architectural quantum' as defined in the script?

An architectural quantum is an independently deployable artifact with high functional cohesion and synchronous dynamic coupling, including all necessary components for the functionality to work.

What book is mentioned in the script that identified the concept of an architectural quantum?

The book mentioned is 'Building Evolutionary Architectures' by Neal Ford, Rebecca Parsons, and Patrick Kua.

Can you describe the 'SISP Squad' system mentioned in the script?

The SISP Squad is a trouble ticket system for customers who buy electronics and purchase a support plan. It allows customers to register, submit problem tickets, and have customer-facing experts fix their issues at their location.

How does the 'SISP Squad' system illustrate the concept of architectural quanta?

The SISP Squad system shows how different parts of the architecture, such as customer login/profile, ticket creation, and operations reporting, can be independently deployable and share the same database, forming separate architectural quanta.

What is the issue with the original 'SISP Squad' system architecture in terms of architectural quanta?

The issue is that while the system appears to have separate parts, the shared database creates a synchronous dynamic coupling that binds them together into a single architectural quantum, which can lead to entanglement and dependency issues.

What is one way to address the problem of architectural entanglement in the 'SISP Squad' system?

One way to address the problem is to create a new user interface for ticket creation, making it a separate architectural quantum independent of the customer profile and login functionalities.

What trade-offs are involved in creating separate architectural quanta for ticket creation and customer profile management?

The trade-offs include potentially disrupting the user experience with separate user interfaces and the complexity of synchronizing session state between the separate deployment units, versus the benefits of having independent, deployable units of architecture.

What alternative solution is presented to avoid disrupting the user experience while addressing architectural entanglement?

An alternative solution is to create a separate ticket creation database, allowing ticket creation to be a separate quantum, while maintaining a good customer experience with a single front end and ensuring data consistency and integrity.

What is the key takeaway from the lesson regarding architectural quanta and trade-offs?

The key takeaway is to understand the importance of the architectural quantum concept for partitioning systems and recognizing dependencies, while also being pragmatic and considering the trade-offs involved in system design decisions.