Where exactly does the Web services middleware layer reside relative to the application? In brief, what does it communicate to the Web service and any other layer? How can it be useful in banking applications?
Web Services Middleware and Web Services Management (WSM) are synonymous terms. The WSM infrastructure is distributed; the enforcement points are either gateway machines that handle the traffic for multiple Web services or agents that are co-resident on the machine running a specific Web service. Typically multiple gateways/agents are controlled by a single management console. The Web service itself and any software consuming the Web service are most often unaware that the WSM infrastructure is present. From the point of view of the Web service the WSM software appears like standard service consumer. From the point of view of the consumer software the WSM appears to be the Web service itself. Communication between the WSM, the Web service, and the consumer software is implemented via WSDL and SOAP format XML documents which are most frequently transported over HTTP.
WSM addresses four key needs: Security, System Management, Standards Interoperability, and Service Virtualization. All four of these are critical to banking applications. Security and system management are baseline needs for industrial strength applications. Infrastructure that can resolve standards interoperability issues is critical given the significant diversity of implementations that are taking part in XML Web services communication. Service Virtualization is the fundamental mechanism for enabling the implementation of the other capabilities while minimizing the impact on existing software implementations.