Building Scalable Microservices with .NET

Introduction

Microservices architecture has become the de facto standard for building scalable, maintainable applications. In this article, I'll share my experience building microservices with .NET Core and MongoDB, along with best practices I've learned along the way.

Why Microservices?

Microservices offer several advantages over monolithic architectures:

• Independent deployment: Deploy services without affecting others
• Technology flexibility: Use the best tool for each service
• Scalability: Scale individual services based on demand
• Fault isolation: Failures in one service don't bring down the entire system

Key Architecture Principles

When designing microservices, I follow these core principles:

1. Single Responsibility

Each service should do one thing well. This makes the codebase easier to understand and maintain.

2. API-First Design

Define clear API contracts before implementation. This ensures consistent communication between services.

3. Database Per Service

Each microservice should have its own database to ensure loose coupling and independent scaling.

Implementation with .NET Core

Here's a basic structure for a .NET microservice:

// Program.cs
var builder = WebApplication.CreateBuilder(args);

// Add services
builder.Services.AddControllers();
builder.Services.AddEndpointsApiExplorer();
builder.Services.AddSwaggerGen();

// MongoDB Configuration
builder.Services.Configure<DatabaseSettings>(
    builder.Configuration.GetSection("DatabaseSettings"));
builder.Services.AddSingleton<IMongoClient>(
    sp => new MongoClient(builder.Configuration["DatabaseSettings:ConnectionString"]));

var app = builder.Build();

// Configure middleware
if (app.Environment.IsDevelopment())
{
    app.UseSwagger();
    app.UseSwaggerUI();
}

app.UseHttpsRedirection();
app.UseAuthorization();
app.MapControllers();

app.Run();

Best Practices

• Implement health checks for monitoring service availability
• Use API Gateway for centralized routing and authentication
• Implement circuit breakers to handle service failures gracefully
• Use distributed tracing for debugging and performance monitoring
• Containerize services with Docker for consistent deployment