Microservices should be scalable and focused on a single responsibility. Each self-contained modular unit handles a specific function within the larger system. Large applications are built from modular components or services such as containers and serverless computing.
Think of microservices as a business with different departments, budgets, and requirements. These requirements change from year to year depending on the company’s needs. It also prevents applications from facing the same level of demand over time. Some aspects may need more demand, others may need more attention. You also need to do different levels of scaling within your application. Microservices allow you to extend and grow in different areas without affecting other areas. And they are extended independently.
We all remember the tenancy of the Single Responsibility Principle in programming. So are microservices. They should do one thing and do one thing well. It also provides the inherent benefit of increased resilience and fault tolerance. Microservices architecture aims to prevent system-wide failures by propagating failures to individual services. If there is a particular obstacle, we know where it is so we can deal with it without affecting anything else.
There are also aspects that can be discovered. By using a service networking solution like Consul, Hashi CorporationAs new services come online, you’ll find that you have one centralized system, a directory of services that defines what they do and how they communicate.
Why you should consider microservices
- Faster time to market: Microservices enable parallel development and deployment of individual components, accelerating the overall development process and reducing the time it takes to deliver new functionality.
- Improved scalability: Microservices can scale independently, allowing enterprises to allocate resources more efficiently and handle different workloads and traffic patterns more effectively.
- Enhanced resilience: The distributed nature of microservices reduces the risk of system-wide failures and ensures continuous service availability and increased system-wide reliability.
- Flexibility and Adaptability: Microservices enable enterprises to leverage diverse technologies and frameworks for different components, making it easier to adapt to changing requirements and incorporate new technologies.
- Easy maintenance and updates: The modular design of microservices simplifies system maintenance and updates as individual components can be upgraded or replaced without impacting the entire system.
Best practices for microservices
It’s important to keep microservices small, focused, and responsible for a single business function. This approach allows us to add additional functionality and avoid sprawl. However, there is no hard and fast rule as to the ideal size, as it depends on the specific application and its requirements.
You also need to design for failure. Fault tolerance is inherently built into running multiple services and microservices by design, but with additional resilience added such as retry mechanisms, circuit breakers, and bulkheads. Consider why ships have bulkheads. They have them for structural integrity, but also in case something goes wrong and the bulkhead closes and the ship doesn’t sink. Many event-based architectures use what are called dead-letter queues. If the message cannot be delivered, it goes into a specific queue where it is examined to determine the reason for failure.
Microservices should be designed according to domain-driven design principles. This means modeling services based on business functions and using a common language to ensure that services fit business needs. Domain-Driven Design focuses on creating software systems based on a deep understanding of the business domain. Its principles guide the design process and help ensure that the software fits the domain and delivers value to the business. Collectively, these principles promote a deep understanding of the business domain and help keep development closely aligned with business needs and changing requirements.
Design with an API-first approach and implement an API gateway that provides a central connection point for facilitating communication between microservices and third-party subsystems. API Gateway handles much of the routing and handles authorization, authentication, and rate limiting. API design patterns are essential to the modularity and reusability of microservices.
Here are some additional microservice best practices.
- Automate testing and deployment. Test and deploy microservices using automation tools such as continuous integration and continuous deployment (CI/CD) pipelines. This reduces the risk of errors and ensures that services are deployed quickly and consistently.
- Use containerization. Containerization provides a lightweight and portable way to package and deploy microservices. Using containerization simplifies the deployment process and increases the scalability and portability of your application.
- Monitor and observe: Microservices should be monitored and logged to ensure that they are performing as expected and to identify any problems or errors. Log aggregators and application performance monitoring (APM) tools can do this. Tracing gives insight into how data flows through distributed systems. These three pillars help provide end-to-end visibility into performance.
- Secure service: Microservices should be secured using best practices such as authentication, authorization, and encryption. Don’t forget container security too. To reduce the overall attack surface, policies should enforce which microservices can communicate with other microservices. Security is part of any design and should be checked throughout all phases of development. This makes your application more secure and protects sensitive data.