Microservices Architecture – 5 Design Patterns Your Development Team Should Know

Microservices have catapulted application development into a new era. Companies are quickly replacing their monolithic apps with microservices apps, breaking down large components into smaller, more manageable parts.

As an architectural style, microservices are based on loosely coupled and independent services. Modularity, scalability, and flexibility are some of the leading benefits of microservices. Microservice design pattern has emerged to be a game-changer for application development.   

But you need to identify how your development team can leverage this architectural approach of microservice design pattern to reap maximum benefits. For this, you need to fully understand the various design patterns involved in microservices and how you can use these effectively.    

This article explains the top eight design patterns your DevOps team should know. It highlights the benefits and challenges of each design pattern of microservices architecture and explains how you can choose the right microservice design pattern for your project.   

Let’s begin!

What are Microservices?

Microservices is an architectural approach to application development that develops apps as a set of independent and loosely coupled services.

Each service or design pattern in microservices represents a particular business functionality and can be developed, deployed, and scaled independently of other services. In this architecture, app services use proper APIs and protocols to interact with each other.

Microservice design pattern allows developers to participate in the application development process efficiently. The goal of microservices and microservice design patterns is to create apps that are highly scalable and easy to manage, develop, and deploy.

Monolithic apps, on the other hand, have interconnected and interdependent services that cannot be scaled, updated, or deployed independently of each other.

This is why monolithic apps lack the scalability and flexibility factors associated with microservices. Microservices architecture patterns give applications high scalability and flexibility.   

Known Cases of Microservices Architecture  

Not many people know, but a lot of giant corporations use microservice architecture. The following microservices architecture examples have evolved from monolithic to microservice architecture. These include:  

• Netflix, a site popular for streaming content, uses a large-scale microservice architecture. This service-oriented architecture allows Netflix to handle large amounts of traffic with its video streaming API.
• Amazon.com originally had a two-tier architecture, which prevented it from scaling. It then migrated to a service-oriented architecture to offer uninterrupted services. It now has hundreds of backend services.
• The auction site ebay.com once had a monolithic architecture, which then evolved into a service-oriented architecture.

Benefits of Microservices

Microservices has totally changed the app development landscape owing to the benefits microservice design pattern offers. Let’s take a look at some of these benefits.

1. Fault Isolation

One of the greatest drawbacks of monolithic apps is that there is no fault isolation – one faulty component can easily bring down the entire app. Microservices and design patterns in microservices overcome this problem due to the independent nature of each service or component.

Your development team can, therefore, handle each service or component failure in isolation from others without jeopardizing the entire app’s performance. All this means that microservices-based apps are more stable and resilient compared to monolithic applications.  

2. Independent Deployment  

Another incredible benefit of microservices apps and microservice design patterns is that you can deploy them independently. This implies that you can change any app component without having to make changes to the other services.

However, if you change a monolithic app component, you must redeploy the entire application. This is risky and takes a lot of time as well.

But with microservices, you can ensure CI/CD pipeline as it allows you to rewrite a service without impacting application performance, thus helping you maintain a top-notch DevOps culture.  

3. Improved Scalability  

Microservices architecture is popular for its enhanced scalability. As each service and microservice design pattern is distinct, you can easily scale them without affecting other services.

For example, if one service is experiencing a sudden uptick in demand, you can independently scale the microservice design pattern without needing to scale the whole app.

Such specific scaling is efficient and cost-effective, making microservices the ideal choice for companies that experience variable workloads.

Why are There Different Types of Microservices Patterns? 

Microservices patterns are essentially proven solutions to common problems in microservices development. These design patterns allow developers to determine how services talk to each other, store data, and handle failure without figuring out everything from scratch every time.  

However, these patterns address specific challenges that arise in different types of microservices. For example, microservices design patterns in Java can have different implementations than in Python because of differences in syntax and features. 

Therefore, there are different types of microservices patterns that are divided into five major categories: 

1. Service Decomposition Patterns 

These patterns deal with breaking down a single monolithic application into multiple small services.  

2. Integration Patterns 

Integration Patterns determine how services integrate and communicate with each other. 

3. Database Patterns 

Some microservices patterns are designed to handle, store, and retrieve data across different services. Database patterns do that by managing data between microservices. 

4. Cross-Cutting Concern Patterns 

These patterns concern aspects that affect multiple layers of the architecture beyond individual services. 

5. Observability Patterns 

Observability patterns gather insights into the internal workings of a microservice application. These patterns monitor the overall health of the architecture. 

Top 5 Design Patterns in Microservices

1. The API Gateway Pattern  

Since each app service in microservices uses fine-grained APIs for communication, managing each API separately becomes very challenging. This is especially true if your application has scores or hundreds of microservices.

But worry not; having a sound grasp of the API Gateway pattern and microservice design pattern helps your development team overcome this challenge.

The API Gateway design pattern acts as a single entry point for clients, simplifying requests and handling authentication, authorization, and load balancing. It can aggregate multiple microservices into a single unified API, making client interactions easier to manage.

This reduces the number of client requests and minimizes latency. However, you must be careful as this microservice design pattern also has some downsides.

For one, it can become a single point of failure unless you ensure that it is highly available. It can also lead to latency problems if you don’t design it properly.  

Nevertheless, the API Gateway pattern and microservice design pattern, if designed properly and coupled with sound operational practices, are excellent ways for developers to simplify client interactions.

2. The Circuit Breaker Pattern  

The rise of microservices applications is composed of services that often have to depend on each other. This means that if one service’s performance is impacted adversely, all the other services that depend on it will also be affected. The Circuit Breaker pattern, as the name suggests, helps to mitigate such situations.   

The Circuit Breaker pattern (microservice design pattern) helps prevent one service failure from cascading into a cascading failure that envelopes other dependent services. Whenever the application finds a failure, this design pattern trips the app and prevents any more calls to the failed service.

Next, microservices architecture patterns proceed to call the service at regular intervals. If these calls are successful, it opens the circuit and allows the service calls to go through.

The greatest advantage of this pattern is that it enables you to maintain app performance and avoid downtimes. However, for the design pattern to work correctly, you need to ensure proper tuning to balance sensitivity and responsiveness to service failure.

Even though you might consider this pattern complex, remember that it allows you to create a highly resilient application.  

3. Database Per Service Pattern  

Modules in a monolithic application typically use the same database. Although such an approach to the microservice design pattern may be easier to manage, it causes tight coupling between the various app modules, which makes maintaining and scaling the app difficult. 

That is where the Database Per Service design pattern comes into action. The Database-per-Service design pattern or microservices architecture patterns ensure high cohesion and loose coupling, as each microservice has its own database. This allows you to scale every microservice independently.    

However, this design pattern’s challenge is that it requires addressing distributed data management problems, such as ensuring data consistency for different services.

Despite this challenge, the Database Per-service architectural design pattern and microservice design pattern help achieve autonomy and data isolation in microservices applications.

4. The Event-Driven Pattern

Maintaining and ensuring data consistency across services can be challenging in a microservices architecture. However, the Event-driven pattern has an answer to this problem as it promotes loose coupling between microservices by enabling them to communicate asynchronously through events.   

In this architectural design and microservice design pattern, a service publishes an event whenever its state changes. Other services follow these events and subsequently update their states. This allows every service to maintain data consistency without requiring synchronous communication.    

Therefore, the Event-driven pattern (microservice design pattern) is an excellent architectural design pattern for decoupling services and improving performance via asynchronous communication. However, adopting the Event-driven pattern requires careful consideration of event schema evolution, event reliability, and message ordering.

5. The Saga Pattern  

Handling distributed transactions across multiple microservices is another challenge of a microservices-based architecture. The Saga pattern (microservices design patterns) is a powerful tool for managing the implementation of business transactions that use several microservices.   

A saga (microservices design patterns) represents a sequence of local transactions, each executed by an individual microservice, to accomplish a global transaction spanning multiple services.

If an error occurs during the saga’s execution, microservices design pattern can trigger compensation actions to undo or correct the changes made by preceding transactions, thus ensuring data consistency.   

A saga often has an orchestrator that coordinates the order of execution of the local transactions and handles error scenarios with the help of design patterns for microservices.

The Saga pattern is suitable for scenarios where you require strict data consistency, but it comes with complexity and the need for careful design to handle failure scenarios. 

6. Service Discovery Pattern 

Also known as Service Registry, this pattern is like a map for all of your microservices. It is a cross-cutting pattern that keeps track of all the services, so that is easier for them to find each other. 

Every individual service has to first register with the service registry until it shuts down. In this way, other services can ask the service registry if they want to locate a specific service.  

As a result, services can come and go without disruption, which improves the overall functionality of the system. Service registry is one of the popular microservices design patterns in Java because Java’s Spring Boot framework simplifies implementing this pattern. 

7. CQRS Pattern 

CQRS (Command Query Responsibility Segregation) is part of database microservices patterns which separates the read and write operations. This is different from the traditional approach that uses the same data model for both operations. CQRS uses separate models for command (write operations) and query (read operations).  

Segregating optimizes each model for specific role, which improves performance and stability. 

8. Bulkhead Pattern 

Bulkhead pattern isolates different parts of a system to prevent failure in one part affecting others. It falls under service decomposition patterns since it isolates parts of an app into different components. 

It gets its name from bulkheads in a ship, which divides the ship into compartments to prevent the ship form sinking if one part is damaged. 

Conclusion

Microservices design patterns play a crucial role in shaping the architecture and performance of a microservices-based system. Each microservices design pattern helps you resolve specific challenges and provides a set of advantages and complexities.

The top five microservices architectural design patterns shared in this article are your best bet for building high-performance, scalable, and resilient microservices apps.   

Xavor’s Mobile App Development team offers microservices architectural solutions and microservices architectural design patterns to leading businesses worldwide. From design consulting and migration to testing and maintenance, our team does it all.   

Feel free to drop us a message at [email protected] to book a free consultation session with our team.