A microservices architecture is a design approach for building a software system as a collection of small, independent services that can be developed, deployed, and scaled independently. A microservices diagram typically visualizes the various components and their interactions within this architecture.

Understand the Components of a Microservices Diagram

Creating a useful microservices diagram starts with clearly understanding the components they normally contain. Here are some key components commonly found in microservices diagrams:

• Microservice: A small, independently deployable service intended to perform a business function.
• API gateway: It aggregates and manages requests and routes them to the appropriate microservices.
• Service registry: A centralized component that keeps track of the locations of microservices.
• Load balancer: It's responsible for distributing incoming network traffic across multiple microservice instances.
• Event bus or message queue: It facilitates asynchronous communication between microservices.
• Container orchestration platform: It automates the deployment, scaling, and management of containers.

Use Standard Notation

Standardizing notation in architecture diagrams is crucial for several reasons. It ensures a common language for describing architectural elements and their relationships, which helps facilitate effective communication among team members, stakeholders, and other parties involved in the project.

There is also less room for misinterpretation when everyone uses the same symbols and conventions. Team members can understand diagrams more easily, reducing the risk of errors and misunderstandings.

In addition, using standard notation helps software projects in the following ways:

Collaboration

Standardized notation provides a shared visual language. Team members from different disciplines or backgrounds can collaborate more efficiently with a common understanding of the architecture diagrams.

Knowledge Sharing

When new team members join a project or information needs to be shared across teams, standardized notation ensures that the knowledge transfer is smooth and accurate.

Maintenance and Updates

A common pain point in utilizing microservices diagrams is keeping them up to date along with changes to the application code or infrastructure. Standardized notation makes maintaining and updating architecture diagrams more straightforward because team members can easily understand and update diagrams created by others. This leads to a more agile and responsive development process.

Visualize Architectures with Different Types of Diagrams

Visualizing architectures with diagrams is a powerful way to communicate complex concepts, relationships, and structures within a system. Different types of diagrams serve various purposes at different levels of abstraction. Here are a couple of common types of architecture diagrams and their purposes.

System Architecture Diagrams

• Purpose: Provide a high-level view of the system within its environment.
• Elements: The system (central box) and its external entities (actors, systems, users) are represented by other boxes around the central system box.

As you can see, the diagram above shows the high-level components of an e-commerce system. It does not provide granular details on each component’s implementation. Instead, it provides an overview of the system’s design as a whole and shows the relationships and interactions (via REST APIs) among a mobile application, API gateway, web application, and three separate microservices.

Sequence Diagrams

• Purpose: Illustrate the interactions among components or objects over time.
• Elements: Lifelines (representing objects or components), messages among them, and control flow (illustrating the sequential flow of data).

In contrast to system architecture diagrams, sequence diagrams focus on a specific functionality. The sequence diagram above shows the order of interactions among four different microservices involved in handling queries, authenticating and authorizing users, and ultimately providing a requested resource to the authorized user.

Conclusion

In summary, creating useful microservices architecture diagrams requires understanding key components and relationships within the system, using standard notation, and leveraging different diagram types to visualize the architecture from various perspectives.

Diagramming microservices architectures effectively enhances communication, collaboration, and decision-making across teams and stakeholders. It also aids in documentation, navigation of system complexity, identification of failure points, and implementation of resilience strategies.

As systems continue to grow more complex, diagramming microservices to distill and navigate intricate architectures remains an invaluable practice for development teams.

What’s next

This is just a brief overview and it doesn't include many important aspects of Microservices Diagrams such as:

• Activity diagrams
• Network diagrams
• How to break down the architecture into smaller, modular diagrams
• Using effective diagramming approaches
• Selecting appropriate tooling

If you are interested in a deep dive in the above concepts, visit the original Multiplayer guide - Microservices Diagram: Best Practices & Examples.