Which of the following is NOT a feature of the Enterprise Service Bus (ESB) architecture?

The feature that is not characteristic of an Enterprise Service Bus (ESB) architecture is the structured and rigid connectivity. ESB is designed to facilitate service-oriented architecture (SOA) through a flexible integration approach, allowing disparate systems to communicate seamlessly with one another. It promotes loose coupling between services, enabling different applications to interact without requiring them to know the details of each other's implementations.

In contrast to rigid connectivity, an effective ESB architecture supports dynamic routing, message translation, and various communication protocols, which provide the necessary adaptability as business needs change. This flexibility is a fundamental aspect of ESB, allowing organizations to evolve their service-oriented strategies without being constrained by a rigid integration model.

The other characteristics listed, such as being highly scalable, reflecting a distributed services architecture, and deploying endpoints/adaptors close to the applications they connect, align with ESB capabilities. Together, these features enable robust, scalable, and efficient integration across a variety of services and applications within an enterprise.