Enterprise Service Bus
What is an ESB?
The recent buzz around Enterprise Service Bus (ESB) is quite natural as connecting systems, people, processes and things is a key business imperative today. All the buzz is matched with the vague definition of an ESB. An ESB is basically a type of software platform known as middleware, that works behind the scenes to assist application-to-application communication. You can consider an ESB as a “bus” which picks up information from one system and delivers to another.
Core Concept of an Enterprise Service Bus
In 2002, the term Enterprise Service Bus first appeared, since then the technology has continued to evolve, inspired by the need of emerging internet applications to communicate and interact with each other. An ESB is a set of principles to integrate numerous applications together in a bus-like infrastructure. The core concept of an Enterprise Service Bus architecture is to integrate different applications by putting a communication bus between them and enable each application to talk to the bus. The idea of an ESB was born out of the need to progress from point-to-point integration which becomes brittle and hard to manage over the time.
Core Functionalities of Enterprise Service Bus
Following are some of the core functionalities of an ESB oriented architecture:
Decoupling system means when they can communicate each other without dependency or knowledge of other system on the bus. One of the most crucial things you can do via an Enterprise Service Bus is decoupling of clients from service providers.
Protocol conversion is the activity of translating sending device protocol to a different protocol of another device to establish compatibility and communication. An ESB enables you to accept one input protocol and communicate on a different protocol with another service provider.
When an ESB receives a message, it redirects the message to appropriate application. But, an ESB also allows you to isolate the client and make some primary changes to the message.
Message transformation is an architectural pattern which acts as a filter between other filters or applications to translate data from one format to another. An ESB allows you to transform an incoming message in several outgoing formats. For instance, XML to JSON, XML to Java objects. .
It is the concept of sending input message to the concerned receiver. There are various types of routing based on requirements. An ESB can redirect a client request to particular service provider depending on deterministic or variable routing criteria.
Process choreography is all about business services whereas service orchestration is the quality to manage the coordination of their actual implementation. The role of an ESB here is to manage process flow and complex business services to carry out a business operation.
A series of steps in a flow must fail or succeed as one unit, here Mule uses a transaction to distinguish such a unit. An ESB provides the ability to render a single unit of work for a business request and provides framework for coordination of multiple heterogeneous systems.
An ESB provides security to services from unauthorized access.
Benefits of an Enterprise Service Bus
Here are some of the advantages of an ESB:
INCREMENTAL ADOPTION
Initially, the number of features offered by some of the best ESBs can seem intimidating. But it’s best to consider Enterprise Service Bus as an integration platform of which you only use the components which meet your current integration requirements.
LIGHTWEIGHT
As an Enterprise Service Bus is made up of many inter operating services, it contains every possible service rather than a single hub, it can be as light or heavy as an organization wants it to be. This makes an ESB the most efficient integration solution.
SOA FRIENDLY
ESBs are built keeping in mind Service Oriented Architecture. Therefore, an organization which is planning to migrate towards an SOA can do that gradually, continuing to use their current systems while plugging in re-usable services along with their implementation.
EASY EXPANSION
In case an organization is aware that they will have to connect additional applications to the architecture in future, an ESB allows integration to the system right away, without worrying about whether the new system will work or not with their existing infrastructure. When a new application is ready, all they need for its working with the established infrastructure is to hook it up with the bus.
DISTRIBUTABLE AND SCALABLE
ESB functionalities can easily be distributed across a geographically dispersed network unlike broker architectures. Moreover, it is comparatively simpler and cost effective to make sure high availability and scalability for essential parts of the architecture while using an ESB as individual components are used to offer each feature.
