SOA.WRK.

Web Service Virtualization

In many Web service implementations, the protocol specific messaging code often built into both the consumer and provider of the service.

This makes it difficult to port the service to other protocols. A common solution to this problem is to separate the messaging aspect out from the consumer or the provider code. The resulting generic consumer or provider can be easily ported using other protocols.

Abstracting the physical service protocol out from web service code is a form of virtualization. Wikipedia, for example, define "Virtualization" as:

"A technique for hiding the physical characteristics of computing resources from the way in which other systems, applications, or end users interact with those resources."

1.virtualization.client-side.protocol

Web Services Invocation Framework (WSIF), is one of the early system that support client-side virtualization of the service protocol. It allows a client to interact with abstract services independent of protocols. The client can be statically or programmatically configured to use a specific service provider. This type of virtualization is supported by most JBI implementations including OpenESB.

2.virtualization.server-side.protocol

OpenESB also supports server-side virtualization of the service protocol. This allows, for example, a generic service provider to interact concurrently with multiple consumers via different protocols. Each consumer interacts with a virtual service provider using a specific protocol.

3.virtualization.others

Like the service protocol, many other physical characteristics of web service can also be virtualized to meet different requirements. For example, the service policy definition attached to a service can be virtualized. This will allow the consumer and the provider to interact using different policy definitions. Another example is high demand service applications. The physical provider of such applications may be virtualized using clusters or grids to provide necessary computing resource needed.

Posted at 08:31AM Apr 24, 2007 by tientienli in Sun  |