Everything You Need to Know About Microservices Architecture in ASP.NET Core

Microservices architecture in .NET Core is an approach to build distributed systems by decomposing them into smaller, independent services that communicate over well-defined, lightweight mechanisms to support continued development and evolution. In comparison to traditional monolithic architectures where all functionality is packaged into a single deliverable unit, microservices architecture promotes building applications composed of many smaller, independent services with well-defined scoped functions.

Some key benefits of adopting microservices include increased agility and independent development enabled by teams working on separate services in parallel without impacting other teams. Services can be deployed, updated, upgraded, or scaled independently without affecting the whole system. Microservices also allow for better resilience as failures are isolated to individual services instead of the entire application. Additionally, they facilitate technical heterogeneity where different services can be implemented using different programming languages and frameworks for better fit. Microservices Architecture in .NET Core allows building highly scalable and resilient applications using ASP.NET Core and related technologies.

Challenges of Adopting Microservices Architecture

However, moving to microservices also introduces challenges of increased complexity both from an architectural and operational perspective. Teams need to consider effective communication mechanisms between services, distributed data management, observability across services, deployment automation, service discovery and more.

Additional testing is required to validate inter-service communication and ensure lack of regression when changes are made independently. Given the distributed nature of microservices, there are also management and operational challenges around deployments, monitoring and maintaining application-level SLAs.

Benefits of Microservices Architecture in ASP.NET Core

  • Independent Scaling: Services can be scaled independently based on demand.
  • Technology Heterogeneity: Different languages/frameworks can be used for different services.
  • Resilience: Failure of one service has limited impact due to isolation.
  • Ease of Deployment: Small codebase and lightweight containers simplify deployment.
  • Organizational Alignment: Teams can work independently on service development.
  • Reusability: Common capabilities can be reused across multiple services.

Drawbacks of Microservices Architecture in ASP.NET Core:

  • Complexity: Many interdependent moving parts makes debugging difficult.
  • Network Latency: Increased network hops can impact performance.
  • Data Consistency: Eventual consistency can be problematic for some use cases.
  • Skillset: Distributed systems skills needed for messaging, monitoring, etc.
  • Vendor Lock-in: Lack of standards can lead to vendor specific solutions.
  • Operational Overhead: Managing many services drives up operational complexity.

Getting Started with ASP.NET Core Microservices

Building modern web apps and services that can scale across platforms is crucial today. ASP.NET Core offers an open-source approach to crafting these cloud-native solutions for Windows, Linux and MacOS. Its lean and modular design makes it easy to construct services with built-in support for logging, error handling and dependency management.

Since ASP.NET Core runs cross-platform, developers can build resilient microservices from their OS of choice and deploy them anywhere without changing code. Its lightweight nature allows these services to start fast and scale economically on basic hardware. Robust .NET tooling and frameworks optimize developer productivity. Overall, ASP.NET Core simplifies building and managing advanced cloud services that are agile and high performing.

Step-by-Step Guide to Create an ASP.NET Core Web API project in Visual Studio 2022

Here is a step-by-step guide to create an ASP.NET Core Web API project in Visual Studio 2022:

  • Launch Visual Studio 2022. Select “Create a new project“.
  • In the “Create a new project” window, select “NET Core Web Application” from the list of project templates.
  • Give your project a name like “MyWebAPI” and set the location. Click Create
  • In the “Create a new ASP.NET Core Web Application” window, select “API” from the list of templates. Ensure “.NET Core” and “NET Core 6.0” (or latest) are selected.
  • Click Create This will create a new ASP.NET Core Web API project with the required NuGet packages and boilerplate code.
  • Open the generated cs file and note the WebApplication builder being used to configure the Web API pipelines.
  • Open the cs under Controllers and note the default GET endpoint. You can test it by running the project.
  • Right click on Controllers > Add > New Scaffolded Item. Select “API Controller – Empty” and give it a name like “ProductsController“.
  • This will generate an empty API controller class. You can add GET, POST endpoints to it and write business logic code.
  • To enable Swagger UI, install the AspNetCore NuGet package. It will be automatically configured on project build.
That’s it! You now have a configured ASP.NET Core Web API project ready for adding RESTful endpoints.

Step-by-Step Guide to Implement a Microservice in ASP.NET Core

Here is a step-by-step guide to implement a single microservice in ASP.NET Core:

  • Create an ASP.NET Core Web API project for the microservice.
  • Define the service boundary and scope. What capabilities will this service provide?
  • Design the API interface – endpoints, request/response models, statuses etc. Use Swagger/OpenAPI.
  • Implement the controller actions and business logic for each endpoint.
  • Configure logging, monitoring, distributed tracing for observability.
  • Add resiliency patterns like retries, circuit breakers using Polly.
  • Validate input data and serialize output data format.
  • Containerize the service using Docker for portability.
  • Configure CI/CD pipeline to build, test and deploy the service.
  • Deploy the service on Kubernetes or Service Fabric for clustering.
  • Scale the service horizontally by adding more container instances.
  • Implement health checks for load balancer
  • Secure the API using authentication and authorization.
  • Handle communication with other services via RabbitMQ/Kafka.
  • Monitor service health, telemetry, logs using tools like Prometheus.
  • Iterate and improve the service over multiple releases.

Designing Microservices

Several key design principles need to be followed when architecting microservices:

  • Services should be designed around business capabilities and loosely coupled to support independent evolution.
  • Each service should have a single well-defined purpose/function and encapsulate that function completely.
  • Services utilize RESTful APIs over HTTP along with supporting technologies like message queues for asynchronous communication between services.
  • Data access is designed to avoid shared database with strict separation of data models between services.
  • Stateless services without session state should be preferred to enable scaling and high availability.
  • Services can be organized effectively around business capabilities and domain models with natural service boundaries following CRUD nouns or business verbs.
Some common considerations in microservices design are how to model data boundaries when services need to share some data or handling stateful services. Event-driven architectures using message queues and events provide an asynchronous and decoupled means of communication between services. Protocol buffers and gRPC are also increasingly being used over traditional RESTful APIs for performance benefits in microservices.

Building Microservices with ASP.NET Core

Using ASP.NET Core, individual microservices can be created as separate web API projects containing controllers, models, business logic services and data repositories. Dependency injection is leveraged extensively for loose coupling between different layers and components. Authentication and authorization security is also implemented at the service layer through options like JWT tokens for secure inter-service communication.

Unit and integration testing of service logic and communications is crucial given distributed nature. Tests should validate service behavior in isolation and when interacting with other services. Mocking proxies and stubbing database/service calls allows thorough testing without actual dependencies.

For deployment and operations, services are packaged as Docker images along with configuration for scaling, health checks etc. Kubernetes clusters provide easy orchestration of microservice deployments and management of containers at scale. Automated pipelines ensure new code changes are built, tested, and deployed in production seamlessly on every commit through mechanisms like GitOps.

Distributed Tracing and Monitoring

Given the distributed nature of microservices, observability into their behavior and interactions becomes important for operational efficiency and debugging failures. Distributed tracing provides end-to-end visibility into requests flowing through multiple services. OpenTelemetry is an open-source project capable of instrumenting ASP.NET Core services to generate traces that can pinpoint slow services, errors, or bottlenecks.

In addition to traces, other metrics like request rates, error rates, memory usage etc for each service instance need to be collected. ASP.NET microservices can expose Prometheus endpoints to scrape and expose metrics. Services also need health checks integrated for effective monitoring. Centralized products like Grafana and Kibana provide integrated views for all monitoring data from microservices.

Service Mesh and Service Discovery

Service mesh like Istio or Linkerd provide additional capabilities of traffic management, authentication, failure handling and observability for microservices that communicate over HTTP. They provide features like load balancing, retries, timeouts, failure handling out of the box without added complexity in services.

For service instances to discover each other, external service registries like Consul or etcd are used. ASP.NET microservices can register their endpoints, attributes on start up with the registry. Clients then use the registry API or libraries to look up and call other services dynamically based on their identifers/names rather than hardcoded endpoints.

Deploying Microservices

Individual microservices built using ASP.NET Core can be packaged into OCI compatible Docker images along with their configuration and dependencies. Microservice images are deployed on Kubernetes clusters through manifests defining replica counts, resource limits, ports mapping etc. Kubernetes orchestrates the distributed system by scheduling container workloads, distributing load, ensuring availability, and automating rollouts.

Continuous integration builds and tests code changes in every commit enhancing quality. Continuous delivery processes then ensure tested and validated code deployments to staging environments on every commit through automation. Tools like Argo, Flux, GitOps provide Git-based infrastructure automation capabilities to minimize time between code changes and production release. In combination, CI/CD removes toil from deployment process and accelerates delivery pace.

Managing and Operating Microservices

While microservices increase agility, operational complexity increases exponentially with number of services. Centralized logging, tracing and dashboard provide visibility into hundreds of services. On-call schedules need to account for specialist skills. Performance bottlenecks or failures impact customer experience more due to lack of centralized control.

Techniques used include consolidating deployments into larger deployable units using techniques like monorepos. Evolutionary database designs avoid frequent schema changes. Circuit breakers, timeouts prevent cascading failures. Self-healing automation rapidly responds to failures through capabilities like auto-scaling. Service level objectives set expectations upfront. Chaos engineering validates resilience under realistic failures. Canary deployments mitigate risk.

What’s the Difference Between Monolithic Architecture vs Microservices Architecture?

Here is a comparison of Monolithic architecture vs Microservices architectures:

Feature Monolithic Architecture Microservices Architecture
Structure Single unified application Suite of independently deployable modular services
Scaling Scale entire app even if specific functions need scaling Scale specific services independently
Flexibility Rigid – hard to change parts of app Flexible – easy to modify, add or replace services
Resilience Entire app fails if one component fails Isolates failures to specific services
Tech Heterogeneity Typically, single language/framework Each service can use different language/framework
Team Organization Organized by function e.g., frontend, backend, DB Organized by service boundaries
Dev Approach Single codebase, release cycles Per service codebase, continuous delivery
Operational Complexity Simpler to operate as single unit Complex – must manage many discrete services
Data Architecture Typically, single database Distributed data across services
Inter-service Communication In-process calls Remote service requests over network

Best Practices for Microservices Architecture in .NET Core

Here are some best practices for building microservices using ASP.NET Core:

  • Decouple Services Via Messaging: Use a lightweight message bus like RabbitMQ or Kafka to communicate between services rather than direct HTTP calls. This decouples the services and allows them to scale independently.
  • Embrace Eventual Consistency: Microservices prefer eventual consistency over strong consistency due to the distributed nature. Design services to gracefully handle out of order or delayed messages.
  • Design Services Around Business Capabilities: Each microservice should model a specific business capability and have a clearly defined boundary. Avoid large, God-like services.
  • Keep Services Stateless: Microservices should not depend on in-memory state or sessions. Use external state stores like Redis if needed.
  • Implement Resilient Clients: Clients of microservices need to implement retries, circuit breakers etc. to handle inevitable failures. Use libraries like Polly for this.
  • Monitor Health/Telemetry: Use monitoring tools to track health metrics, request rates, latencies etc. for each service. Quickly identify issues.
  • Implement CI/CD: Automate builds, tests, and deployments of services using CI/CD pipelines and tools like Jenkins. Promote immutable artifacts.
  • Use Openapi/Swagger: Define APIs using OpenAPI spec and generate interactive documentation using Swagger. Keep contracts versioned.
  • Validate Input/Output: Use validation frameworks like FluentValidation to validate all input and output data. Catch issues early.
  • Use Organizational Boundaries: Align teams and codebases with service boundaries so each team owns end-to-end functionality.
  • Scale Horizontally: Microservices should be stateless and horizontally scalable. Use containers & orchestrators like Kubernetes.

Final Thoughts on Microservices Architecture in .NET Core

In summary, ASP.NET Core delivers an optimal end-to-end framework for constructing distributed, microservice-driven solutions. Its lightweight, cross-platform design and extensive .NET tooling simplify building, deploying, and managing these services.

When architecting microservice systems with ASP.NET Core, architects should apply best practices for independent scaling, distributed messaging, and monitoring across service boundaries. Adopting sound architectural principles and operational patterns enables ASP.NET Core to support robust, resilient microservices platforms.

FAQs on Connected Cloud-ERP System

What are microservices?

Microservices are small, independent services that work together as a system. Each microservice focuses on completing one task and can be developed, deployed and scaled independently.

What is service discovery in microservices?

Service discovery allows services to find and communicate with each other. Popular techniques include client-side discovery and server-side discovery via a service registry.

How do microservices communicate?

Microservices communicate via well-defined APIs, usually REST over HTTP. Message brokers and event buses are also used for asynchronous communication.

How do you implement API Gateways in microservices?

API Gateways sit between clients and microservices. They act as a single entry point and handle tasks like routing, authentication, load balancing, caching, request shaping and more.

What is microservices architecture in .NET core?

Microservices architecture in .NET Core involves building a system as a collection of small, modular services rather than a monolith. Each service has its own business logic and communicates via APIs using HTTP, gRPC, RabbitMQ etc.

Is microservices a 3 tier architecture?

No, microservices are not simply 3-tier architecture. They can have more than 3 tiers. Key difference is microservices are decentralized – each service is independent with own database.

What is the difference between Web API and microservices in .NET core?

Web APIs in .NET Core implement specific business functionalities and can be consumed by various clients. Microservices are self-contained, independent services that make up a larger application.

What is the basic architecture of microservices?

The basic architecture includes independent services communicating via APIs, decentralized data management, infrastructure automation, and organizing services around business domains.

Is .NET Core good for microservices?

Yes, .NET Core provides an excellent platform for building microservices. Key features like DI, config management, logging, and Kubernetes support make it well-suited.

Is REST API a microservice?

Not necessarily. REST API is a type of interface for accessing microservices. But a microservice has business logic beyond just API – it handles data, messaging, operates independently.

What is microservices in C#?

Building microservices in C# and .NET Core involves creating small, independent services with specific responsibilities that work together as a bigger system using .NET APIs.

What is API gateway in microservices?

An API gateway is an entry point that sits in front of microservices, routing requests, handling auth, security, caching, load balancing, and more. It provides a consolidated API layer.

Amelie Lamb

Amelie Lamb

Amelie Lamb is an experienced technical content writer at SoftwareStack.co who specializes in distilling complex software topics into clear, concise explanations. She has a talent for taking dense technical jargon and making it engaging and understandable for readers through her informative, lively writing style.

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