If you work with IT or cloud computing, you're sooner rather than later apt to come upon the microservice/ service-oriented architecture (SOA) debate. Both approaches are alike in that both break large, complex operations into smaller, more flexible components. Both scales meet the speed and operational demands of the company's escalating data and involve cloud or hybrid cloud environments for deployment. Hereon, opinions differ. Some developers say microservices are an improvement of SOA, while others say there are key differences.
Most important: Microservices are used for applications, while SOA is geared towards enterprises.
What is Microservices?
Certain IT projects could be too complex or large to manage, test, and deploy, so software developers fissure them into single containerized applications. Each function has its responsibility and team of developers.
This helps the company speed processes, cut costs, and redress problems of open enterprise areas without dismantling operations of the whole. It also makes functions more effective and fault-resilient, among other benefits.
Example
Amazon.com divides into standalone categories (shipping, selling, customer support, etc.), where diverse teams develop and troubleshoot their particular application. That's in contrast to the traditional monolithic architecture, where each category would be indistinct from the entire enterprise.
What is Service-Oriented Architecture (SOA)?
Service-oriented architecture (SOA) is just that. The enterprise constructs its IT system to deliver service rather than pivot around technical or operational aspects. Each function contains its relevant code and data integrations for achieving a particular service in SOA software architecture. As a result, the whole system is interoperable to enhance efficiency, agility, and productivity.
Example
A single security service is split into diverse components for authentication, authorization, audit, policy, encryption, and so forth. Each is furnished with its code and focuses on its delimited responsibility. (Other functions could include checking a customer's credit, logging on to a website, or processing an application).
Differences Between SOA and Microservices?
Some developers insist microservices are essentially an upgraded version of service-oriented architecture (SOA), while others find the two approaches complementary. Difference include:
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Microservices is leaner and more agile than SOA.
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Microservices is open source and more functional than SOA.
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Microservices are standalone and smaller than most specialized components in SOA systems.
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Microservices are granular and narrower in their communication than SOA.
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Microservices can be developed, deployed, and tested faster than functions in SOA. Their lifespan is shorter.
In technical terms:
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Microservices uses lighter-weight protocols like HTTP REST, while SOA prefers SOAP.
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In microservices, each service is developed with its communication protocol, while in SOA, the middleware enterprise-service bus (ESB) is used.
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SOA needs governance, while microservices can do without.
To bring it all together with a possible use case, consider this: Enterprise-oriented SOA uses a continual flow of information and computing signals, achieved by protocols like RESTful APIs. In application-scoped microservices, synchronous communication would only cause latencies and weaken its resilience. So microservices use asynchronous communication, such as the publish/subscribe (Pub/Sub) model that helps them gain agility.
Bottom Line
Both microservices and service-oriented architecture (SOA) can best be described as an army of small specialized services (soldiers) trying to conquer a massive problem together instead of one big fighter doing everything. Although some developers tag microservices as the lightweight version of SOA, the real difference is in SOA staking out the enterprise while microservices focus on applications. Either model helps managers save time and costs as it slices monolithic systems into components, making services easier to work with.
Which is best for you?
Both approaches speed up automation. Larger and more diverse enterprises could benefit from the broader and less granular SOA design. Smaller environments, including web and mobile applications, are easier to develop with microservice architecture.
Extra Credit
There's a science, if not an art, to microservice/ SOA applications, which is why entire courses and books dedicate themselves to this topic. Here are Google Cloud's best practices for microservice performance.
