Main Difference
ESB is an abbreviation for Enterprise Service Bus, which is a software architecture that provides integration of enterprise applications and services for complex architectures, such as middle infrastructure platforms. SOA is an abbreviation for Service Oriented Architecture that provides ‘transactional’ data transfers, with no third party software required.
ESB
An ESB’s primary function is to provide the connections between communicating applications – acting much like a router to control the data. It is commonly used in enterprise application integration (EAI) or service-oriented architecture (SOA) principles. The interaction and communication between components are across the bus, which has a similar function to the physical computer bus to handle data transfer or message exchange between services, without writing any actual code. ESB as an infrastructure software service-oriented model works as a managed message system that provides routing, data transformation, translation upon a client’s request and event-interpretation. It is often needed to transform messages into a format that the application can interpret. ESB is also used to change data content or execute services via a rule engine.
SOA
SOA (Service-oriented architecture) is a set of architectural concepts used for the development and integration of services. SOA deals with distributed computing in which consumers consume a set of interoperable services. Multiple consumers can consume a single service and vice versa. Therefore, SOA is often used to integrate multiple applications that use different platforms. For SOA to properly operate, services should be loosely coupled with operating systems and the technologies of underlying applications. SOA developers create services using units of functionality, and make them available over the internet. Web services can be used to implement SOA architecture. In that case, web services become the units of functionality of SOA accessible over the internet. Web services can be used by anybody without being concerned about the platforms or the programming languages used for developing them. SOA is directly built upon the principle of service-orientation, which talks about services with simple interface that can be accessed independently by users, without worrying about the actual platform implementation of the service. Service oriented architecture is approach to have software resources in an enterprise available and discoverable on network as well defined services. Each service would achieve a predefined business objective and perform discrete units of work. The services are independent and do not depend on the context or state of the other services. They work within distributed systems architecture.
Key Differences
- SOA is an architectural approach where we expose ‘service’ in a coarse-grained manner whereas ESB is a technical implementation that aids in delivering a SOA.
- SOA brings cost effective, reusable and low lead time solutions to an organization whereas ESB enables low cost integration and used by companies with limited IT resources.
- SOA is way of building the next generation of applications from ‘lego blocks’ called Services whereas ESB is a piece of infrastructure software that provides APIs for developers to create services and send messages between services.
- SOA is just like a car and ESB is like a road on which this car runs.
- SOA is an architectural model for implementing loosely coupled service based applications whereas ESB is a piece of infrastructure software that helps developers to develop services, and communicate between services through suitable APIs.