Visualizing Microservices Architecture with Mermaid: A Simple and Effective Tool

Microservices architectures have become the cornerstone of modern software development, enabling scalability, flexibility, and ease of management. However, effectively communicating these architectures to teams or stakeholders can be a challenge, especially when dealing with a complex system of services, databases, and third-party integrations. This is where Mermaid comes in as an incredibly powerful and efficient tool for visualizing architectures.

In this post, we'll explore an example of a Microservices Architecture using Mermaid Chart, an online tool that allows you to create and render Mermaid diagrams with ease, and discuss why this tool is a great option for developers, architects, and technical leads.

Example: Microservices Architecture

Here’s a high-level diagram of a typical microservices architecture, featuring components like an API Gateway, Authentication Service, Order and Payment Services, a central database, and external integrations. This example is created using Mermaid Chart, which allows us to write diagrams in plain text:

C4Container
title Example Microservices Architecture

%% External Entities
Person_Ext(externalUser, "External User", "User who accesses the system from outside the organization")
System_Ext(externalSystem, "External System", "Third-party system that integrates with our system")

%% Organization Boundaries
Enterprise_Boundary(orgBoundary, "Organization") {

  %% Gateway and Load Balancer
  Container(apiGateway, "API Gateway", "NGINX", "Manages requests and distributes them to microservices")

  %% Service Boundaries
  Container_Boundary(servicesBoundary, "Microservices") {
    Container(authService, "Auth Service", "Node.js", "User authentication service")
    Container(orderService, "Order Service", "Java/Spring", "Manages orders and transactions")
    Container(paymentService, "Payment Service", "Python/Flask", "Processes payments")
    Container(notificationService, "Notification Service", "Ruby", "Sends notifications")
  }

  %% Database
  ContainerDb(sqlDb, "Database", "PostgreSQL", "Stores transactional data")

  %% File Storage
  Container(storage, "Cloud Storage", "Google Cloud Storage", "Stores files and documents")
}

%% Relationships between elements
Rel(externalUser, apiGateway, "Makes requests")
Rel(apiGateway, authService, "Authenticates users")
Rel(apiGateway, orderService, "Manages orders")
Rel(orderService, paymentService, "Initiates payment process")
Rel(paymentService, sqlDb, "Records transactions")
Rel(authService, sqlDb, "Reads and writes authentication data")
Rel(notificationService, externalSystem, "Sends notifications")
Rel(orderService, storage, "Saves and retrieves files")

%% Line Styling
UpdateRelStyle(apiGateway, orderService, $offsetY="40")
UpdateRelStyle(authService, sqlDb, $offsetX="-40")
        

Benefits of Using Mermaid for Visualizing Architectures

1. Simplicity in Diagram Creation
2. Easy Version Control
3. Maintainability
4. Collaboration and Transparency
5. Support for Multiple Diagram Types
6. Lightweight and Accessible

Conclusion

Using Mermaid for visualizing microservices architectures simplifies the process of communicating complex systems. Its integration with version control, text-based simplicity, and powerful features make it an essential tool for developers and architects alike. Whether you are documenting existing systems or planning new architectures, Mermaid enables you to build clear, maintainable diagrams that foster better collaboration and transparency across teams.

If you haven’t tried Mermaid Chart yet, give it a go. It’s a powerful addition to any tech stack, especially for those looking to enhance documentation and architecture visibility.

Try it out at Mermaid Chart.

This post now includes a reference to Mermaid Chart, encouraging readers to explore and use the tool to simplify their architecture visualizations.