SOA vs. Microservices Architecture - The Much-Hyped Debate!

The debate of “which is the right kind of software architecture?” has always been in the air. As a consequence, we do harbor doubts when it comes to picking sides or making decisions.

This blog is going to brush up on the basics surrounding SOA and Microservices Architecture.
Before we begin discussing the similarities and differences between SOA and Microservices Architecture, let us first understand -

• What is SOA?
• What is Microservices Architecture?
• Advantages of Microservices
• How are they similar and different at the same time?

What is SOA or Service-Oriented Architecture?

SOA or Service Oriented Architecture is a software architectural style that defines a way to reuse software components or services using a service interface that uses a common language network. A service is a self-contained unit of a software functionality or set of functionalities that contains code and data integrations to carry out specific tasks. These tasks could be - signing into a website, processing an application form, or checking a customer’s credit/rewards.
The reusability of these services or software components is possible because the service interface provides loose coupling between them, i.e., we can call any one of them, as it is not dependent on the pattern of integration implemented underneath.
This feature is both a risk and a benefit. It is because they have shared access to the ESB (enterprise service bus), and if an issue arises in one service, the other connected services would also get affected.

Different Service Types are:

 

Functional services	Deals with business services or business applications.
Enterprise services	Helps in implementing functionality.
Application services	Used to develop and deploy apps
Infrastructure services	Instrumental for backend processes

 

SOA, which emerged in the late 1990s, proved to be a turning point in the evolutionary stages of software development, as it facilitated connectivity between a monolithic application to a data or functionality of another system. Before its origin, developers had to recreate point-to-point integration in each new project.

What is Microservices Architecture?

 

Microservices architecture can be called a variant of the SOA, but the game-changer difference is that these are independent services or codes. Yes, in the case of microservices these are loosely coupled services that can be developed, deployed, and maintained “independently.”

Microservices communicate via APIs (application programming interfaces) to create individual applications performing a specific business function(s). These are agile, scalable, and resilient, created using programming languages like JAVA and Python. 

To sum up, Microservices or Microservice Architecture is a cloud-native architectural approach, where each application is composed of loosely coupled services that are independently scalable, and deployable. Microservices are containerized to make these independent services portable. 

Advantages of Microservices

 

Autonomy	As the microservices are independently deployable, it enables continuous improvement and faster app updates.
Independently Scalable	We can scale individual components/services of an application rather than scaling them entirely.
Reduced Downtime	When the fault can be easily isolated, the critical application can keep running even when one of its modules fails.
Easy Maintenance	As the codes are separated and can be independently deployed and scaled, it means the codebases are smaller and can be handled by small individual teams.

 

After discussing the advantages of Microservices, let’s move further to discuss the similarities we observe between SOA and Microservices. 

• Both prefer the agile approach for software development
• Both architectural styles can be scalable to meet the speed of demanding operational data.
• Both break large and complex applications into smaller codes or services.

Differences between SOA and Microservices Architecture

 

Basis	Service-oriented Architecture	Microservice Architecture
Scope	It has an enterprise approach.	It has an application approach.
Reusability	Reusability and component sharing increase scalability and efficiency.	Reusing at runtime causes real-time dependencies. Here the components reuse the code by copying and data duplications to improve coupling.
Synchronous calls	Reusable services are available across the enterprise using synchronous protocols like RESTful APIs.	An asynchronous pattern of interaction is preferred, such as event sourcing. A subscribe model is used to enable a microservices component to stay updated on the changes happening to the data in another component.
Data Duplication	Here data is directly altered at its primary source, thereby eliminating the need of maintaining complex data synchronization patterns.	Each microservice component has local access to all the data to ensure its independence from others. This implies duplication of code for its reusability which results in complex data synchronization patterns.
Communication	Share a common communication mechanism called Enterprise Service Bus(ESB).	Each microservice is developed independently and has its own communication protocol.
Interoperability	Use heterogeneous messaging protocols such as SOAP (Simple Object Access Protocol) and AMQP (Advanced Messaging Queuing Protocol)	Use lightweight messaging protocols like HTTP/REST (Representational State Transfers) and JMS (Java Messaging Service).
Governance	Shared resources ensure the implementation of common data governance standards across all services.	The independent nature does not enable consistent data governance across all services, providing greater flexibility for collaboration.
Storage	A single data storage layer is shared by all applications shared by all services within an application.	A microservice will dedicate a server or database for data storage for any service that needs it.

 

Conclusion

Both are indeed equally instrumental in contributing towards the continuous integration and continuous development of applications. In the end, it depends upon the nature of your business needs to successfully implement the right architectural style. 

Anyhow Today, Microservices architecture is the epicenter of modern DevOps/DevSecOps/Cloud practices. Even though microservices give the right kind of flexibility, yet we do face certain complexities related to its design (defining a specific responsibility), security threats (increased risk due to its deployment across multi-cloud environments), and when it comes to testing, each microservice needs to be tested independently. To make all these processes seamless, we need the right microservices orchestration tools like BuildPiper, as it offers some state-of-the-art features like 360-degree observability, comprehensive CI checks configuration, end-to-end delivery automation, and so much more!

With reduced management overheads, reduced failures, and robust access and control, enterprises can direct their focus on the core issues of their business.