Enterprise Service Bus
From AMWA
An Enterprise Service Bus is a software construct used to enable SOA communication. When implemented in software architecture, it is considered to be a part of the middleware layer (see Middleware). There’s no standard of ESB.
An ESB is not a specific technology, but instead an implementation of a set of capabilities in the middleware. An ESB is a bundled solution that includes one or more of the following functional components:
- Legacy adapters: service-enable functionality within legacy applications
- Service containers: host newly developed services
- Service composition tools: define and host composite services
- Message bus: manage message delivery between endpoints, supporting capabilities such as routing, load balancing, reliable messaging, event-driven processing, transactions, synchronous/asynchronous, etc.
- Format and protocol adapters: enable interoperability among heterogeneous middleware systems
- Mediators: perform capabilities such as transformations, validation, authentication, authorization, logging, etc.
While the functionality of an ESB can be logically described as a hub-and-spoke configuration, its physical implementation does not have to be configured that way and can in fact be highly distributed.
