10. An ESB is an "architectural stack of technologies" that works together to enable developers and architects alike to create intelligent, adaptable applications that can automate business processes, as well as interactions, between multiple systems and organizations. One may argue that a combination of SOAP/HTTP and WSDL can be used as an "alternative ESB," but this is not the case.
Which of the following could be considered as valid arguments why the combination of SOAP/HTTP and WSDL fall short of being a true ESB?
a) The scenario requires each participating application to be SOAP/HTTP enabled. An ESB, on the other hand, provides support for alternative integration techniques
b) Service addressing and routing is typically controlled in client code. Therefore the SOAP/HTTP style is more a "point-to-point" integration style
c) Both SOAP and WSDL carry semantic information, while an ESB should manage messages regardless of their contents
d) There is no way to substitute the implementation of one service provider over another without changing the service requesters (client) code. The code typically invokes the service/s over a specific protocol and aims at a specific address.
ANSWERS: A, B, C, D
Even though the combination of SOAP/HTTP and WSDL fulfills some ESB requirements (e.g. SOAP/HTTP supports request/response messaging, HTTP protocol is widely used and readily available, etc.), they still fall short of being classified as an "ESB alternative".