Microservices architecture has gaining increasing popularity over the past several years as a way to build scalable and maintainable applications. The key idea behind microservices is to break large, complex software systems into smaller, independent services that can be developed, deployed and scaled independently. In this blog post, we’ll take a look at how to build microservices with .NET.
What are Microservices?
Microservice architecture is a style of building distributed systems that focus on breaking applications down into extremely small, independent services. Each service runs its unique process and communicates through a well-defined, lightweight mechanism like an API, usually over HTTP. These services are built and deployed independently and can be written in different programming languages.
Some key characteristics of microservices include:
- Highly Maintainable and Testable: Each service is small enough to be managed by a small team focused on that service. This makes them easier to maintain and test.
- Loosely Coupled: Services are independent, with little to no knowledge of other services. This allows for more flexibility.
- Independently Deployable: Services can be deployed independently without coordination between teams. This allows for more rapid deployment of updates.
- Organized Around Business Capabilities: Services are centred around specific business capabilities vs technical capabilities. This aligns better with how businesses operate.
- Decentralized Data Management: Each service manages its own database and data persistence. This reduces dependencies and bottlenecks.
- Infrastructure Automation: Automated infrastructure through technologies like containerization is leveraged for easy deployment and scaling.
Why Use Microservices?
There are several key motivations for building applications with microservices instead of traditional, monolithic architectures:
- Agility: It’s much easier to iterate and deploy new pieces of an application independently. This allows you to respond faster to dynamically changing business requirements.
- Scalability: Each service can scale independently to meet demand. This eliminates bottlenecks and enables cost optimization.
- Resiliency Issues: One service has minimal impact on the availability of other services. This improves overall uptime and reliability.
- Maintainability: Smaller codebases and teams make it easier to maintain quality code over time. This reduces technical debt and makes evolving the system easier over time.
- Productivity: Parallel development by multiple teams is much easier. Smaller teams allow you to get more work done faster.
- Reusability: Common capabilities get refactored into reusable services that can be leveraged across products and teams.
- Interoperability: Microservices developed in different languages can still interact through common APIs. This prevents vendor or technology lock-in.
Challenges with Microservices
While microservices provide many benefits, there are also notable challenges to consider:
- Complexity: Many simple services are more complex to manage end-to-end than one monolithic app. Additional tooling and processes are required.
- Network Overhead: Lots of small, chatty services can add substantial network overhead vs one monolith. Caching and asynchronous messaging can offset this.
- Data Consistency: Managing data consistency across services is challenging, especially for complex business transactions.
- Testing: Testing inter-service communication and dependencies requires more sophisticated end-to-end testing practices.
- Deployment Orchestration: Deploying updates across multiple services requires orchestration and can slow down release cycles.
- Operational Complexity: Operating and monitoring many services with dispersed logs and metrics introduces operational overhead.
Microservices vs Monoliths
There are good reasons to build either monolithic applications or microservices apps. Microservices work better for large, complex applications and product-based companies. Monoliths can sometimes be easier to build and manage for smaller, simpler scenarios.
Benefits of Following the Monolithic Framework
- Simpler to develop
- Easy to deploy
- Straightforward data management
- Testing is simpler
- Better performance
Benefits of using Microservices Architecture
- Agility and maintainability
- Decoupled team process
- Technology heterogeneity
The decision depends ultimately on your specific goals, priorities and tradeoffs. Both architectures have their appropriate use cases.
Microservices Communication and APIs
In order for independent microservices to work together as a system, they need to communicate with each other. The most common approach is to expose APIs (Application Programming Interfaces) over HTTP that each service can call to integrate with other services. Common patterns include:
- REST APIs: These leverage HTTP methods to expose CRUD operations on resources. REST is popular for public APIs due to wide tooling support.
- Async Messaging: Communication modes like queues, topics, and pub/sub avoid synchronous coupling between services but can increase overhead and complexity. Useful for workflows, notifications and integration events.
- RPC: Remote procedure calls act like calling a method locally in another service. Requires common data formats across services. It is more coupled but efficient for some scenarios.
Well-defined APIs that are developed, tested and versioned independently from any particular implementation are critical for microservices. API Gateways can also help manage crosscutting concerns like security, rate limiting, logging, etc, for all APIs.
Microservices Data Management
Since microservices own their data persistence layer, handling database scaling, redundancy, consistency and more brings additional challenges compared to monolithic data models. Common distributed data architecture patterns for microservices include:
- Database per Service: Each service manages its database schema and instance(s). It’s simpler but only works for complex transactions across services.
- Shared Database: Multiple services share a common database server but with isolated schemas. It is easier to manage but has tighter coupling.
- Event Sourcing: Database changes are emitted as events, creating an immutable log of record changes over time. Enables advanced patterns but requires more investment.
- CQRS: Command Query Responsibility Segregation splits read vs write data models. It can simplify data replicas for scaling.
- Sagas: Long-lived transactions implemented as a sequence of independent ACID transactions coordinated by a Saga process. Useful for complex workflows across services.
Regardless of data architecture, DevOps practices around evolving database schemas, migrating data and managing deployments are critical for microservices’ success.
Building Microservices with .NET
The .NET platform from Microsoft provides a great foundation for building microservices in a Windows environment and offers some useful microservice-focused capabilities:
- .NET Core: Lightweight, cross-platform implementation of .NET optimized for microservices. It is faster to iterate and deploy due to smaller footprints.
- ASP.NET Core Web framework: For building web APIs with .NET Core. Makes creating RESTful services easy and productive.
- Kestrel: Lightweight web server included in ASP.NET optimized for microservices hosting scenarios.
- GRPC: A high-performance RPC framework built on HTTP/2 standards. Simplifies connecting .NET services efficiently.
- SignalR: A real-time web communication library is often used for pushing notifications between microservices.
- OpenTracing: Instrumentation library for distributed tracing across microservices, including OOTB in .NET Core.
- Steeltoe: Extensions for building microservices on Cloud Foundry, Kubernetes and other platforms. Handy for DevOps.
- Type: Simple tool for running .NET microservices locally during development; there is no need for Docker!
.NET has robust support for building microservices across teams in large enterprises or fast-moving small teams alike. The language, tooling and ecosystem components come together to make .NET a productive platform for implementing complex microservices systems. However, you need to hire .NET developers with ample experience in integrating microservices with .NET to gain the most out of this practice.
Common .NET Microservices Deployment Targets
Microservice architectures allow you to scale the application infrastructure independently of the application code. The deployment “target” defines the environment the microservices run on. Here are some popular options with .NET:
- Kubernetes: Container orchestrator perfect for automating deployment, networking and scaling of containerized apps. First-class support for .NET.
- Service Fabric: Distributed systems platform from Microsoft designed specifically for stateful microservices. Tight .NET integration.
- AWS Fargate: AWS Fargate is a serverless container platform on AWS. Easy way to run containers without managing servers.
- Azure Container Apps: Serverless container hosting from Microsoft built on top Kubernetes. Integrated with other Azure services.
- Cloud Foundry: Popular open-source PaaS optimized for continuously delivering 12-factor apps. Works well for .NET microservices.
- Bare VMs: Custom machine images with container hosts enable ultimate flexibility without being locked into any vendor or third-party service.
This is a comprehensive overview of building microservices with .NET. It covers what microservices are, key benefits and challenges, how microservices compare to monolithic architectures, common communication patterns and data architectures for microservices, .NET platform capabilities useful for microservices and common deployment targets for hosting .NET microservices. Hire dedicated developers with ample experience in .NET development to transform your monolithic .NET project into microservices.