What Is a Microservices Architecture?
Microservices architecture is an approach to creating software systems that involves dividing a large application into independent small-scale services that can be developed, scaled, and deployed separately. Each microservice has a designated business function and communicates with the other services through well-defined APIs.
This approach allows for greater flexibility, scalability, and agility in software development, as well as better fault tolerance and easier maintenance.
Benefits of Microservices Architecture
There are numerous benefits to using a microservices architecture to build applications, including:
- Scalability: In a traditional monolithic application, all components scale together, which can result in over-provisioning and waste of resources. Microservices allow for granular scaling, which means that individual services can be scaled down or up based on their specific needs. This results in more efficient resource utilization and cost savings.
- Flexibility: Microservices are built around business capabilities and are not dependent on a specific technology stack. This means that different teams can use the technology stack that best suits their needs, without being restricted by a common technology stack.
- Fault tolerance: In a monolithic application, a failure in one component can impact the entire application. With microservices, all services are independent of each other and can continue to function even if another service fails. This results in a more resilient system and reduces the risk of downtime.
- Easy maintenance: Microservices are smaller and more focused, which makes them easier to understand, test, and maintain. Changes to one service can be made without affecting the overall system, which reduces the risk of introducing bugs or breaking functionality.
- Technology diversity: Microservices allow for the use of different technology stacks for different services. This means that teams can use the best tool for the job, which can result in higher productivity and better quality code.
- Agility: Microservices enable continuous delivery and deployment, which means that changes can be made and deployed quickly without causing other problems across the system. This allows teams to respond to changing business needs and market conditions more quickly.
- Cost-effective: Microservices can be deployed in a containerized environment, which allows for efficient resource utilization and reduces infrastructure costs. This can result in significant cost savings, especially for large-scale applications.
Learn more in our detailed guide to microservices vs. monolith
Microservices Architecture Design Patterns
The aggregator pattern is used to combine data from multiple microservices into a single response for the client. The client forwards requests to the aggregator service, which then sends requests to the necessary microservices to collect the required data. The aggregator service then combines the data and sends a response to the client.
Chained or Chain of Responsibility
The chained or chain of responsibility pattern is used to pass a request through a chain of microservices, with each service responsible for performing a specific task. Each microservice in the chain handles part of the request and passes the request on to the next microservice in the chain. This pattern is useful for tasks that require multiple steps, such as processing a payment or validating user data.
The asynchronous messaging pattern is used to decouple microservices by sending messages between them. Instead of calling a microservice directly, one microservice sends a message to a message queue, which is then picked up by the receiving microservice. This pattern allows for more fault tolerance and scalability, as each microservice can handle messages independently.
The event sourcing pattern is used to capture all changes to a system as a series of events. Each microservice in the system listens to these events and uses them to update its own state. This pattern provides a complete audit trail of all changes to the system and allows for easy rollbacks.
The circuit breaker pattern is used to prevent cascading failures in a microservices system. If a microservice fails repeatedly, the circuit breaker opens and stops sending requests to that microservice. This allows the system to continue functioning even if one microservice is unavailable.
The decomposition pattern is typically used to break down a monolithic application into smaller, separate microservices. This pattern allows for better scalability, fault tolerance, and flexibility in development.
Learn more in our detailed guide to microservices design patterns
4 Tips for Success in Microservices Architecture Design
1. Have a Separate Data Store(s) for Your Microservice
Having a separate data store for each microservice ensures that every service is responsible for storing its own data, which reduces dependencies and tight coupling between microservices. This approach, known as data sovereignty, makes it easier to manage and scale your architecture. Each microservice should have a dedicated database, with an API in place to allow communication between the databases and the respective services.
2. Proxy Your Microservice Requests Through an API Gateway
An API gateway acts as a single entry point for all client requests, effectively abstracting the complexity of the underlying microservices. It is responsible for routing requests to the appropriate microservices, aggregating responses, and handling cross-cutting concerns such as authentication, rate limiting, and monitoring. By proxying requests through an API gateway, you can improve security, manageability, and maintainability of your microservices architecture.
3. Ensure API Changes Are Backwards Compatible
Backward compatibility is essential to prevent breaking changes when deploying updates to your microservices. By adhering to this principle, you can ensure that existing clients can continue to use your services without any issues.
When making changes to your API, consider adding new features using methods such as introducing new endpoints or adding optional parameters. If breaking changes are unavoidable, provide a reasonable migration path for clients to follow.
4. Version Your Microservices for Breaking Changes
When breaking changes are inevitable, it's crucial to version your microservices appropriately. By doing so, you can allow clients to choose which version of the service they wish to use, providing them with a smooth transition.
You can use various strategies for versioning, such as including the version in the API URL or using custom HTTP headers. Ensure that you communicate these changes effectively to your clients and give them ample time to migrate to the new version.
Related Content: Read our guide to microservices vs. soa