What is the Difference Between Microservices and SOA

The main difference between Microservices and SOA is that Microservice is a type of SOA that divides an application into a group of separate services while SOA is a software design style that allows the components of the application to provide services to the other components over a network.

Usually, a monolithic application is a single unit that hosts multiple software components. It is possible to host and deliver the components together.  There are some drawbacks in monolithic applications. Moreover, programmers can implement them using various technologies. Therefore, those applications are not flexible and failure in one component can affect the entire system. Thus, this causes these applications to be unreliable. Moreover, these applications are not scalable and make it difficult to develop large applications. Microservices and SOA are two architectures that helps to overcome the limitations of monolithic architectural applications.

Key Areas Covered

1. What is Microservices
     – Definition, Functionality
2. What is SQA
     – Definition, Functionality
3. Difference Between Microservices and SQA
     – Comparison of Key Differences

Key Terms

Microservices, Monolithic Application, REST API, SOA

Difference Between Microservices and SOA - Comparison Summary

What is Microservices

Microservice is an architectural style that divides an application into a set of independent services and each service works separately. Therefore, it is a decentralized architecture or fine-grained architecture.

Difference Between Microservices and SOA

There are two types of services in a Microservice: functional and infrastructure service. Functional service is a service which contains the business logic of a particular feature while infrastructure service is a service that performs non-business and non-functional operations.

In a microservice, the communication between components occurs using an API layer. In other words, there is no middleware. Generally, a REST API helps to establish communication between the components.

For example, assume a shopping application. User account, product catalog and shopping cart are separate features. Each feature divides into separate tasks and each task handles a separate service. For instance, the shopping cart feature has tasks such as display product and update product tasks. Moreover, the display product service handles the display product while the update product service handles the update product service. In other words, each service performs a particular task.

What is SOA

SOA is a style of software design that provides services to the other components using application components. These application components connect to each other using communication protocols. A service is a discrete unit of functionality. Furthermore, it is accessible remotely and can be updated independently.

Main Difference - Microservices vs SOA

Various types of services in SOA are as follows.

Business Service is a service that performs the core business operation.

Enterprise Service implements the functionality defined by the business service and it uses the application service and infrastructure service.

Application Service represents the core functionality of the feature and it is possible to invoke them directly or by a user interface.

Infrastructure Service is a service type handles the non-business and non-technical operations. (auditing, security etc.)

Additionally, different languages and components help in developing the components. In SOA, there is a messaging middleware such as Enterprise Service Bus (ESB) to allow communicates between various components of the application.

For example, assume a shopping application. It has separate applications like user account application, shopping cart application and product catalog application. Each application consists of multiple small tasks. Moreover,  all of them connect together to create a single application service.

Difference Between Microservices and SOA

Definition

Microservices refer to a software development style which is a variant of the service-oriented architecture (SOA) that structures an application as a collection of loosely coupled services. In contrast, SOA is a style of software design where services are provided to the other components by application components, through a communication protocol over a network. Thus, this describes the difference between microservices and SOA.

Architecture type

Furthermore, microservices is coarse grain architecture or decentralized architecture while SOA is fine-grained architecture or centralized architecture.

Service types

While microservices has functional and infrastructure services, SOA has business, enterprise, application and infrastructure service. Hence, this is another difference between microservices and SOA.

Communication

Also, one other difference between Microservices and SOA is that Microservices use an API layer for communication while SOA uses middleware for communication.

Threading

Furthermore, microservices are single threaded whereas SOA is multithreaded. Thus, this is also a difference between Microservices and SOA.

Application

It is possible to expose and access all services of microservices through the same remote access protocol while SOA helps to integrate several systems using different protocols in a heterogeneous environment.

Conclusion

The main difference between Microservices and SOA is that Microservice is a type of SOA that divides an application into a group of separate services.  Overall, SOA is a software design style that application components provide services to the other components over a network. In brief, Microservice is a variant or type of SOA.

References:

1.“Microservices.” Wikipedia, Wikimedia Foundation, 25 Apr. 2019, Available here.
2.“Service-Oriented Architecture.” Wikipedia, Wikimedia Foundation, 19 Apr. 2019, Available here.
3.edureka! YouTube, YouTube, 12 Mar. 2018, Available here.

Image Courtesy:

1.”New Service” By Xiaoan888 – Own work (CC BY-SA 4.0) via Commons Wikimedia
2.”SOA DP Event-Driven Messaging B” (CC BY-SA 3.0) via Commons Wikimedia

About the Author: Lithmee

Lithmee holds a Bachelor of Science degree in Computer Systems Engineering and is reading for her Master’s degree in Computer Science. She is passionate about sharing her knowldge in the areas of programming, data science, and computer systems.

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