Companies have been using the enterprise service bus (ESB) for decades to connect applications to each other. Typically, these applications were monolithic — built comprehensively by including all services needed within the app. Then came the expansion of cloud services and separate, pluggable microservices. Because microservices represent a fundamental shift in the way enterprises manage their resources, it’s helpful to explore the role both ESB and microservices play to understand the advantages of one over the other.
An ESB, or enterprise service bus, is an integration approach that uses a centralized software component to create integrations between applications. To create an ESB, developers build a communication bus between different applications. Then, they enable each application to talk to the bus, which in turn allows sharing of data and communications between the connected applications. This standardized approach to application integration means DevOps won’t have to build custom, point-to-point integrations for each application.
It helps to view ESB in the context of how it is used in the overall computing architecture. ESBs are the building blocks of SOA, or service-oriented architecture, an architecture approach designed to foster communication between services through loose coupling. SOA is the overarching approach to a system’s architecture, and ESB is the communication tool that makes the approach possible.
For more background on how ESB fits into SOA architecture, read “ESB and SOA”.
Microservices are a cloud-native architecture approach in which a single application is composed of many independently deployable components, or services. A departure from the traditional, monolithic application approach of large, tightly coupled applications, microservices instead make use of containers. Using containers creates a scalable and distributed system that avoids the bottlenecks of a central database.
Microservices are separated by their business capability. For example, an application’s cart, customer data and product information are all stored within its own database and communicate in real-time through APIs, event streaming or messaging protocols to create the application’s overall functionality.
The main distinction between ESB and microservices is that an ESB is an integration tool, while microservices are just as the name suggests — small service components that are combined to create an application.
An ESB is a centralized, standardized hub that inputs, transforms and outputs data so various applications and services can communicate easily. Microservices are free of dependencies on other microservices. They can be plugged in and out of applications as needed. While they take different approaches, ESB and microservices are after the same goal — make cloud-based application development and operations easier and more efficient.
To fully understand the difference between ESB and microservices, it’s helpful to look at not just how they compare, but also at how ESB and microservices relate to their respective architecture models.
A microservices architecture is made up of many highly specialized services that development teams connect to build an application’s functionality. As microservices architecture design continues to advance, the benefits of decoupling services increase; they are more agile, scalable and responsive to the needs of organizations today.
ESB, on the other hand, is a product initially designed for the pre-cloud, legacy system era. Integrations take longer to develop and are less flexible than if you take a microservices architecture approach. The centralized integration hub of an ESB can make troubleshooting problems easier than identifying the cause within your microservices. However, without fault tolerance, the ESB can also be a single point of failure for the whole enterprise, which results in a bigger overall problem to fix.
To learn more about the distinction between ESB and SOA architecture and microservices architecture, read, “SOA vs. Microservices: What’s the Difference?”
Some benefits and drawbacks of using ESB include the following:
Some benefits and drawbacks of using microservices include the following:
The short answer is no. An ESB can connect both small, specialized web services and older, enterprise-wide services and applications. This makes it the best solution for integrating large on-premises solutions with SaaS solutions and other cloud-based environments.
Yet, in recent years, microservices have become the preferred architecture model in many organizations. There are several reasons why microservices have the advantage over ESB and SOA today:
Here are some use cases for when microservices would be the preferred architecture approach:
While microservices have the edge today, ESB is likely to adapt architectural aspects of microservices to meet demand. The rise in container technology and the need to integrate multiple cloud environments will influence how ESB architecture is used and they ways in which it will evolve and become more modern.
As companies today look for an undisruptive solution to shift IT infrastructure toward the hybrid cloud, they will need a modern approach to integration. For many companies, this will include transforming workloads based on SOA and ESB patterns to a more lightweight and flexible model.
Companies can leverage the scalability and flexibility of the cloud by deploying independent microservices, while ensuring legacy systems remain relevant with evolving ESB offerings. Using automation can standardize the process, regardless of the approach, making the transition faster and more efficient. IBM gives you access to AI-powered Automation capabilities, including prebuilt workflows, to help accelerate innovation and digital transformations.
Learn how IBM Cloud Integration Solutions can speed integration development by up to 300%, reduce costs by over 33% and increase overall operational efficiency.
Explore modernizing integrations and leveraging middleware investments with IBM Cloud Pak® for Integration. This hybrid integration platform uses an automated, closed-loop approach that supports multiple styles of integration within a single, unified experience.
Get the full picture of where your organization needs to go to advance its integration technology. IBM’s Integration Maturity Assessment provides a critical look at your organization’s integration maturity and what actions you can take to get to the next level.