What is an ESB?

• An Enterprise Service Bus (ESB) is fundamentally an architecture. It is a set of rules and principles for integrating numerous applications together over a bus-like infrastructure. 

• ESB products enable users to build this type of architecture, but vary in the way that they do it and the capabilities that they offer. The core concept of the ESB architecturewww.skillbricks is that you integrate different applications by putting a communication bus between them and then enable each application to talk to the bus. 

• This decouples systems from each other, allowing them to communicate without dependency on or knowledge of other systems on the bus. The concept of ESB was born out of the need to move away from point-to-point integration, which becomes brittle and hard to manage over time. 

• Point-to-point integration results in custom integration code being spread among applications with no central way to monitor or troubleshoot. This is often referred to as "spaghetti code" and does not scale because it creates tight dependencies between applications.

Why use an ESB?

• Increasing organizational agility by reducing time to market for new initiatives is one of the most common reasons that companies implement an ESB as the backbone of their IT infrastructure.

•  An ESB architecture facilitates this by providing a simple, well defined, "pluggable" system that scales really well. Additionally, an ESB provides a way to leverage your existing systems and expose them to new applications using its communication and transformation capabilities.

Choosing an ESB platform:

There are many ESB platforms out there, from big proprietary vendors to niche and open source vendors. On paper, there are lots of similarities. Here are some points to consider when making an ESB selection.

Lightweight

Mule is the most lightweight integration platform available, with the fully loaded distribution weighing in at 40 MB. It is modular by design so you can strip out unwanted modules if you need to reduce the footprint. We don't see "lightweight" as just about size either; it is also the cost of making changes to existing integrations and the amount of heavy lifting you need to do to make changes. The Mule run-time offers modularization and super-fast hot deployment as well as a configuration model that makes it easy to re-order and add/change functionality.

Not just mediation

Most vendors think of an ESB as purely mediation between systems and have separate products for hosting business logic and publishing services. We see this as unnecessary complexity. Mule provides a light and scalable service container for publishing REST and SOAP services. Since Mule integrates tightly with Spring, it means developers can also leverage the capabilities of Spring to implement business logic.

Accessible - any developer can learn Mule

Mule uses common tools that all Java developers are familiar with, such as Maven, Eclipse, JUnit and Spring. Mule uses an XML configuration model (similar to Spring) to define logic, and custom code can be written in a variety of languages, including Java, Groovy, JavaScript, Ruby or Python. Also, MuleStudio helps new developers get up to speed quickly with a graphical development environment.

Scaling up, scaling down

Mule was designed for horizontal scale on commodity hardware - no need for big iron. Mule's runtime is easily embeddable into an application. It can also be embedded in your application server such as Tomcat, JBoss or WAS or directly in your application. More importantly, Mule provides JUnit support so that it can be embedded in a JUnit test case. This is powerful because it means you can create repeatable unit tests for integrations that will run on a developer laptop and can be incorporated into a continuous build.

Message agnostic

A powerful feature of Mule is that the container is message agnostic. This means it does not force XML messages on its users. While XML is common, there are many scenarios where you will want to use JSON, flat files, Cobol Copybooks, binary and file attachments, streams and Java objects. Our graphical Data Mapper is equally not fussy about the data that can be mapped. What's more, Mule streaming allows developers to process large messages efficiently.

Cloud ready

If you'd rather leave the application architecture, hosting and monitoring of your integration to the integration experts then CloudHub™ is for you. CloudHub is an integration Platform as a Service (iPaaS) that gets you up and running in minutes. CloudHub offers a multi-tenanted, elastic platform with connectivity to 150+ SaaS, Social Media and infrastructure services and the ability to connect to your on-premise applications. CloudHub applications run on Mule standalone and vice versa. This means that whether you are deploying on-premise or the cloud, there are no new concepts to learn and the developer experience is the same. No need to learn a new way of doing things.