There has been a growing debate about the differences if any between Microservices and Service-Oriented Architectures (SOA). While both Microservices and SOA have more architectural similarities than differences, they are totally different from each other. These two architectures rely on services as their main component but in terms or service characteristics, they vary greatly. In order to distinguish between the two, it is important to first understand their architectural differences.
Microservices architecture is basically a particular way of developing mobile applications, web or software as independent suites of services known as microservices while SOA is a software architecture pattern allowing application components to offer services to other components over a network through a communications protocol.
Microservices Vs SOA
In Microservices architecture, there is very little or no coordination at all needed among services unlike SOA where coordination with multiple groups is required for creation of business requests. SOA facilitates component sharing while Microservices uses “bounded context” to minimize on sharing. A bounded component in this case means the coupling of a component as well as its data into a single unit that has minimal dependencies. Systems that are built on SOA are more likely to be slower than those built on Microservices since SOA solely depends on multiple services in order to fulfill a business request.
SOA has a messaging middleware that offers several additional capabilities that are not present in Microservices such as message enhancement, mediation and routing as well as message and protocol transformation. On the other hand, Microservices consists of an API layer that is between services and service consumers. The architectures of SOA depend on messaging (MSMQ, AMQP) as well as SOAP as the primary remote-access protocols while most Microservices architectures only rely on two protocols namely simple messaging (MSMQ, JMS) and REST. Microservices has a protocol that is usually homogeneous in nature. However, SOA promotes multiple heterogeneous protocols through the messaging middleware component.
- Microservices – Fundamentals by IBM
- IBM Microservices Specialization – Develop and deploy MICROSERVICES with KUBERNETES
- Getting started with microservices [From zero to production]
- Building Microservices on AWS
- The Complete Microservices With Spring Course
Microservices basically tries to simplify the architecture pattern through reduction of the choices for integration thus if you need to integrate many systems with different protocols in a heterogeneous environment, then SOA should be your choice. But if your services can be exposed and accessed via the same remote-access protocol, Microservices is a better choice. You can easily find many Online Certificate Courses on Microservices and SOA here. One of the most fundamental capabilities offered in SOA is contract decoupling which offers a high level of decoupling between consumers and services. Microservices on the other hand does not offer contract decoupling.
Nothing really new was introduced in Microservices architecture but it is basically a logical evolution of service-Oriented Architectures (SOA). For more complex and large business application environments that may need integration with several heterogeneous applications, SOA will be better suited. However, using SOA patterns to implement workflow-based applications with a well-defined processing flow may be a bit challenging. Equally, small applications may also not be well suited for SOA since they do not require messaging middleware component but the Microservices pattern is a perfect choice for well-partitioned and smaller web based systems. Microservices lacks messaging middleware, a factor that makes it unfit for large and more complex environments.
If you are looking to develop an application with greater control, then Microservices is a great option but as your business grows, you might need more capabilities like heterogeneous systems integration or complex request transformation where you may be required to switch to SOA pattern.