SOA vs. Microservices: What's the Difference?

Microservices is the software architecture method that most organizations use today. However, the services-oriented-architecture or SOA vs microservices debate is far from over. In this article, we attempt to serve you with the differences between the two and which one would be the best fit for your organization.

What is Service-Oriented Architecture?

Service-oriented architecture (SOA) is an architectural pattern in which application components provide services to other components via a communications protocol, typically over a network. It is a distributed computing approach that promotes loose coupling between services, allowing them to be independently developed, deployed, and changed over time. SOA provides a way to integrate multiple services into a single, unified system and supports the reuse of services across multiple applications.

SOA and Microservices have many points in common:

• Both use cloud environments for agile application development and deployment.
• They are easily scaled up to meet big data demands.
• Both involve breaking up of large applications into smaller packs for easy working.
• Each service is responsible for itself.

Many other differences between the two are also apparent on closer examination, as detailed below.

SOA-Evolution

SOA-based applications became popular in the 1990s. They represent an important step in the evolution of applications development. Before SOA became commonplace, each new development project required that monolithic applications were connected to data or functionalities in other systems involving complex integrations from each point to another, recreated for every new project. With the advent of SOA, all such complex integrations could be avoided.

Download our ebook: Porting from Monolith to Microservices: is the shift worth it?

Before discussing microservices vs. SOA, understanding the basics of SOA is vital. The SOA architecture provides loose coupling between different services made up of code and data integrations specific to a business function. This makes use of the reusability aspect of the services. The loose coupling ensures that any service can be called without knowing how the integrations work in depth. For development teams, this means time is saved by reusing components from other applications.

There are other disadvantages. Services being connected to the Enterprise Service Bus (ESB), problems can occur across other services when issues arise in one. Solutions for SOA-based architecture use XML data.

SOA and Service Types

SOA’s services are made of three components: i) an interface that defines how the provider will execute requests emanating from the service consumer; ii) the contract defining the provider and consumer interaction; and the iii) service code/implementation.

There are 4 different service types that an SOA can provide:

• Functional services or business services, are critical for business applications.
• Enterprise services that help to implement functionality
• Application services are used to develop and deploy the apps.
• Infrastructure services enable backend processes for security/authentication

These services are combined in a manner to produce higher-level applications and services.

A Short Note on Microservices

Microservices are similar to SOAs in that they are also loosely coupled independent services that exhibit a high degree of cohesion. The microservices communicate via APIs and are designed to build independent applications (to perform specific business functions) that are resilient and scalable. Golang, Python, and Java are languages used to build microservices.

Read our blog : How to find the best microservices development company

Microservices are cloud-based and operate out of containers, making them both scalable and portable. Code can be updated easily and results in big savings of time. Different applications can be built using different technologies and each service can be modified or scaled independently of another. This makes the system more fault tolerant than other systems.

SOA and Microservices: Key Differences

The best way that the difference between SOA and microservices can be explained is that of‘scope’. Whereas the SOA displays an ‘enterprise’ scope, the microservices architecture possesses an ‘application’ scope.

Given below are a few instances when differences between these systems come into play:

Reuse

Being of the enterprise scope, the SOA requires some level of reuse which helps to increase both efficiency and scalability.

Read our blog : What Kind of Challenges Can Microservices Help You Overcome

In the microservices architecture, reusability during runtime increases dependencies. Therefore, microservices applications reuse code and also have data duplication to provide a high level of decoupling.

Synchronous Calls

All the reusable services in SOA are available across the enterprise application through synchronous protocols such as RESTful APIs.

For microservices, generating synchronous calls within the service creates dependencies that reduce the resilience. Also, to reduce latency, asynchronous calls are preferred within a microservice.

Duplicated Data

In SOA systems, all the data is obtained from and also altered at its primary source. Therefore, there is less need to maintain complex data synchronization information.

Read our blog : Why Business leaders should care about Microservices

In microservices, the primary aim is for every service to remain independent of the other. Therefore, this means duplication of data to some extent. This adds to the complexity of the system but is well accepted in view of the microservices agenda.

Do you want to know how microservices can help your business? Talk to us today!

Microservices Vs. SOA-Other differences

Many of the characteristics of SOA and microservices are similar. However, there are more differences between the two than what are listed above that determine their use cases.

Communication: Each service in a microservices setup is developed with an independent communication protocol. However, in an SOA they are threaded using a common mechanism called an enterprise service bus (ESB). The SOA manages all the services that are delivered via ESB and any single failure can affect the entire communication system.

Interoperability: Microservices make use of lightweight messaging protocols (HTTP/REST/JMS), whereas SOAs use heterogeneous messaging systems such as SOAP (Simple Object Access Protocol), MSMQ (Microsoft Messaging Queuing) and AM

Granularity of services: Microservices are made up of many small services, each of which is designed to do one single function and do it very well. SOA services can be small and specialized or be as big as enterprise-level applications.

Read our blog : Advantages of Microservices Architecture, Disadvantages of Microservices Architecture

Working speed: Development and troubleshooting are easy with SOAs. However, they are also slower compared to microservices. Microservices work faster because they do not share the architecture as much as SOAs.

Governance: The shared resources of SOA make for common data governance standards to be implemented across all the services. Microservices do not have consistent data governance standards and this allows for more flexibility.

Storage: The SOA architecture includes a single data storage layer shared by the services within an application. However, in microservices, a server or database is dedicated to storage of data which is used by the specific service.

Migration

SOA is usually the system that replaces a monolith. Organizations that want to migrate to a microservices architecture from SOA employ DevOps. Microservives help to address specific business needs.

Why are Microservices Best for you?

If your business system functions within a smaller environment that does not require a robust communication layer, then you can settle for a microservices architecture. Microservices give you improved developer productivity and allow for simplified maintenance and debugging. Applications become more resilient and microservices systems allow better fault isolation. In more ways than one, microservices are a better choice.

Download our ebook: Porting from Monolith to Microservices: is the shift worth it?

Do you want to transition into microservices from SOA? Call us today!