The explosive adoption of cloud-based applications by modern enterprises has created an increased demand for cloud-centric integration platforms. The cloud poses daunting architectural challenges for integration technology like: decentralization, unlimited horizontal scalability, elasticity and automated recovery from failures. The traditional ESBs were never designed to solve these issues. Here are a few reasons why ESBs are not the best bet for cloud-based integration
Performance and Scalability
Most ESBs do simplify integration but use a hub-and-spoke model that limits scalability since the hub becomes a communication bottleneck. To scale linearly in the cloud, one requires a more federated, distributed, peer-to-peer processing approach towards integration with automated failure recovery. Traditional ESBs lack this approach.
JSON and REST
ESBs evolved when XML was the dominant data-exchange format for inter-application communication and SOAP the standard protocol for exposing web services. The world has since moved on to JSON and today, mobile and enterprise APIs are exposed using REST protocols. ESBs that are natively based on XML and SOAP are less relevant in today's cloud-centric architecture.
Security and Governance
These are key concerns for any enterprise that chooses to move to cloud. With multiple applications in the cloud, enterprises are not always comfortable with centralized security hubs. Security and governance need to be decentralized to exploit the elasticity of the cloud. Old-guard middleware products were typically deployed within the firewall and were never architected to address the issues of decentralized security and governance.
Latency and Network connectivity
When your ESB lives in the external cloud, latency becomes a critical challenge as end-points are increasingly distributed across multiple public and private clouds. Traversing a single hub in such an environment leads to unpredictable and significant performance problems which can only be addressed with new designs built ground-up with Cloud challenges in mind.