Microservice Architectural Patterns Play Critical Role in Realizing Benefits
If you transact business with customers in the cloud or rely on cloud applications to drive business processes, application agility is key. You need to continually roll out new functionality that keep your external and internal users fully engaged.
To improve your application agility, microservices is the answer you’re looking for. This software development technique allows you to break large applications into loosely-coupled, independent modules that communicate with each other through lightweight-language agnostic protocols like RESTful APIs. The architectural style has become widely-used among developers for web-based applications—thanks to its ability to manage APIs and execute highly-defined, discrete tasks.
Businesses that successfully adopt microservices can significantly accelerate the time it takes to convert their great ideas into customer value that generates revenue and sustains long-term customer relationships. That’s because microservices do not require development teams to rewrite and deploy an entire application when they add new features. And since microservices applications produce a smaller codebase, on-going software maintenance is much easier and takes less time.
As your development team considers adopting the microservices technique, or if you need to enhance your current microservices approach, it’s important to get a feel for the different architectural patterns that pertain to microservices. In this blog, we present an overview of some of the more widely-used patterns and how each one fits into an overall microservices architecture.
Database Per Service Pattern
The database per service pattern is the most often used pattern since almost every service needs to persist data in some kind of database. The primary challenge lies in determining the database architecture across a microservices application. Most client transactions need to access and join data that spans multiple services, so to make sure each database responds correctly to each client request, you need to keep persistent data private to each microservice and accessible only via its API.
The saga pattern applies to microservices environments where the database per service pattern has already been put into play. Each service has its own database, but some client requests span multiple services. The saga pattern maintains a certain level of transactions on the database side, which helps maintain data consistency across services. This pattern is particularly helpful when executing transactions that need to tap into multiple databases such as a customer order that requires access to product and account info.
The composite pattern comes in handy when you have applied the database per service pattern and client queries that join data from multiple services create complex views. A high-level service makes the calls and creates the proper output while also removing complexity from the view. You can also define an API composer to invoke the services that own the data and perform in-memory joins of the results. By utilizing this pattern, you create a simple way for applications to query data in a microservice architecture.
API Gateway Pattern
An API gateway pattern is typically used as a single entry point for all your services to avoid exposing the services to the front-end application and the Internet. Microservices typically provide fine-grained APIs, which means that clients need to interact with multiple services. The gateway routes the requests to the appropriate services and can be programmed to run an adapter code that exposes a different API to each client, depending on their requirements. The gateway can also apply security controls to verify if clients are authorized to perform each request.
Client Load Balancer
The client load balancer equalizes the payload among multiple instances of a service and is particularly helpful for maintaining high-level application performance on a microservice that sends out calls to other microservices. The balancer registry always updates itself, so if one instance goes down, the registry automatically removes the instance without any manual intervention. Because the balancing takes place on the client side, you can also program the load balancer based on the compute resources serving each microservice.
The discovery pattern maintains a map of names with addresses and contains information about the health of the services. The API gateway and client load balancer are highly-dependent on the discovery pattern to identify the location of service instances when services are requested by clients. The discovery service queries a registry that then forwards client requests to an available service instance.
Right Pattern Mix Solves Microservices Complexity Challenge
Adopting a microservices architecture can be complex because development teams have to manage and support many moving parts. And as you continue to add more microservices, you have to be sure they can scale. When more services interact, you also you increase the possible failure points.
You can solve these microservices challenges by deploying and integrating the right mix of patterns that ensures each microservice can communicate and exchange data with every other microservice. The pay-off of faster time-to-market for new functionality is well worth the effort—whether you’re providing improved services to your customers or a more efficient way for employees to do their jobs.
Are Microservices the Right Choice?
While microservices can pave the way to substantial improvements to an organizations culture, capabilities, and ability to complete, they are not without risk. Understanding and planning for the disadvantages of a microservices migration is the key to success. We hope after reading this article you are more aware and better prepared to tackle the challenge. Now that you are familiar with the disadvantages of a microservices architecture, feel free to read this article about microservices advantages.
If you would like more information, or assistance with planning and preparing for a microservices migration, we can help. We have helped dozens of companies decouple their monolithic applications and were able to successfully navigate the pitfalls that a complex microservices migration presents. Please drop us a line below, or give us a call, and we can help walk you through every step of your journey.
You might also like these other articles on microservices:
- Why should I choose microservices?
- How do I get started with microservices?
- What are the advantages of a microservices architecture?
- What are the disadvantages of a microservices architecture?
- What microservice pattern should I choose?
If you are interested in learning more about microservices please download our 11 page white paper "Making Microservices Work for Your Organization."