If you happen to work in the IT sector or the cloud computing field, you are probably aware of the service-oriented architecture (SOA) vs microservices debate. After all, everyone is talking about microservices and agile applications these days. Understanding the most reliable way to develop and deploy applications is an important concern for any data-driven business today, as it is the future of smartphones & portable devices. Having an option of service-oriented architecture (SOA) and microservices provides valuable flexibility for building and running applications that traditional monolithic approaches don't. However, it becomes difficult to distinguish the differences between the two to identify which is better for your organization. Microservices arrange an application as a series of distinct, single-purpose services, on the other hand, SOA is a group of modular services that communicate with each other to support applications and their deployment. Both approaches have significant differences in architecture, component sharing, data governance, communication, and other elements. 

At first glimpse, both approaches sound very similar. In some ways, they both are different from a traditional, monolithic architecture in which every service has its responsibility. However, both are scalable and agile approaches.  Even with having so much in common,  a closer look at the two approaches shows important differences.

What is service-oriented architecture (SOA)?

Service-oriented architecture (SOA) is an enterprise-related approach to software development that makes use of reusable software components or services.  Each service involves code and data integrations that are required to execute a specific business function. For instance, checking a customer’s credit, signing in to a website, or processing a lease application. The SOA interfaces provide loose coupling, which means that they can be called without the knowledge of how the integration is implemented underneath. Due to this loose coupling and the way services are published, developers can save a lot of time by just reusing cross-platform app development tools in other applications across the company.  

SOA appeared in the late 1990s and represents an essential stage in the evolution of application development and integration. Before SOA was even an option, connecting an application to data or functionality in another system needed a complicated point-to-point integration that developers had to recreate for any new development project. Revealing those functions through SOA projects reduces the need to recreate the wide integration every time. Since SOA has larger, more modular services that are not independent of one another, it’s designed to share resources as much as possible.

Features of SOA

Here are some important features of SOA:

• SOA uses interfaces that solve complex integration problems in big systems.
• SOA interacts with consumers, providers, and suppliers by using the XML schema.
• As it reuses the service, so the expense is slightly lower for software development and mobile app personalization.
• SOA uses message monitoring to enhance performance measurement and detects any security threats.
  
  

Advantages of Service-oriented Architecture (SOA)

Here are a few pros/benefits of Service-oriented architecture:

• SOA can adjust or modify the various external environments
• The companies can develop an application without replacing existing applications.
• Editing and updating any service is easier
• Services have a common directory structure, which allows consumers to access the service data from the same directory each time.
• Services interact with other applications using a common language which means it is independent of the platform
• SOA allows reusing the service of an existing system, alternately building the new system.
• It offers to plug in extra services or to improve existing facilities to meet the new business requirements.
  
  

What are Microservices? 

Microservices architecture is generally regarded as an evolution of SOA as its services are more refined, and function independently of each other. Therefore, if one of the services fails in an application, the app will continue to work since each service has a separate purpose. The services in microservices communicate via application programming interfaces (APIs) and are set up around a particular business domain. Collectively, these services fuse to make up complex applications.

Since each service is independent of the other, a microservice architecture can scale better than other approaches used for application development and deployment. This feature also gives microservice applications more fault tolerance than other application development techniques. Microservices are often built and deployed in the cloud; in many situations, they operate in containers. Consequently, microservices are configured to share as few service resources as possible.

Features of Microservices

Here are necessary features of Microservices:

• It's very convenient to use multiple technologies as multiple features in an application.
• The cost of scalability is little
• Modules are loosely coupled in microservices
• Management of the project can be modularized.
• It is an ideal service for developing systems where you can't predict the types of devices which may one day be accessing your application.
  
  

Advantage of Microservices

Here are the pros/benefits of using Microservices:

• It lets the team develop, deploy, and scale their service independently of all the other teams.
• Simpler architecture pattern which is easy to understand for developers.
• The IDE is faster that makes developers faster and productive.
• The web container starts faster; this helps to make the process of deployments and developments faster.
  
  

The main difference between SOA and microservices

The main difference between the two approaches gets down to scope. To simply put, service-oriented architecture (SOA) has an enterprise scope, while a microservices framework has an application scope. Many of the core principles of each architecture become unsuitable when you overlook this difference. If you accept the difference in scope, you may instantly realize that the two can likely complement each other, rather than compete.  Below are a few cases where this characteristic comes into play:

Reuse

In SOA, reuse of integrations is the main goal, and at an enterprise level, aiming for some level of reuse is necessary. In a microservices architecture, building a microservices component that is reused at runtime throughout an application leads to dependencies that decrease agility and resilience. In SOA the reuse of integrations 

Synchronous calls

The reusable services in SOA are available across the company using mainly synchronous protocols such as RESTful APIs. But, within a microservice application, synchronous calls include real-time dependencies, resulting in a loss of flexibility. It may also cause latency, which influences performance. Within a microservices application, interaction models based on asynchronous communication are favored, such as event sourcing, in which a subscribe model is used to allow a microservices component to remain up to date on improvements happening to the data in another component.

Data duplication

A clear purpose of providing services in an SOA is for all applications to synchronously get a grasp of and make changes to data right at its source, which reduces the need to manage complex data, synchronization models. In microservices applications, each microservice has access to all the data it needs to secure its independence from other microservices,  and certainly from other applications, even if this means some duplication of data in other systems. This duplication does add complexity, so it must be matched against the profits in agility and performance, but this is acknowledged as a reality of microservices design. 

Other key differences between SOA and microservices

• Communication: In a microservices architecture, each service is developed individually, with its separate communication protocol. In SOA, each service must share a common communication mechanism called an enterprise service bus (ESB). The ESB can become the only point of failure for the whole enterprise, and if a service slows down, the entire system can be affected.
• Interoperability: In order to keep things simple, microservices use lightweight messaging protocols like HTTP/REST. On the other hand, SOAs are more open to heterogeneous messaging protocols.
• Service granularity: Microservices architectures are composed of highly specialized services, each of which is intended to do one thing thoroughly.  The services that makeup SOAs can range from small, specialized services to enterprise-big services.
• Speed: By leveraging the benefits of sharing a common architecture, SOAs make development and troubleshooting simple. However, this also makes SOAs operate more gradually than microservices architectures, which reduce sharing in favor of duplication.
  
  

Which is best for you?

Both approaches have their perks, so how can you conclude which one will work best for your goals? In general, it depends on how big and diverse your application environment is. Bigger, more diverse environments lend themselves more to service-oriented architecture (SOA), which supports integration between heterogeneous applications and messaging protocols via an enterprise-service bus (ESB).  Smaller environments, including web and mobile app solutions, don't need such a robust communication layer and are more straightforward to develop using a microservices architecture. However, both SOA and microservices are applicable in different use cases for the same organization. 

Evon Technologies is an offshore software consulting company that provides custom app development solutions. We have a dedicated team who design, code, and create your application to include all of the crucial areas required for your company. We enable organizations to quickly access both microservices and SOA through the cloud or hybrid cloud deployment. We make sure that the application is unique and user-friendly for the visitor and content management team. We bring attributes that include cross-platform compatibility, usability, and scalability, to your application. If you or your organization decide on implementing any of the architecture in application design, then contact us today or drop an email at This email address is being protected from spambots. You need JavaScript enabled to view it..