Requirements for webservices to meet SOA

[Dhiren Joshi]

For a webservices to be meet the SOA does it necessarily have to publish the WSDL to a UDDI.
If the WSDL is available by other means to the end point user does that webservices implementation still qualify as a SOA if it hasnt published the WSDL to UDDI.
Thanks
Dhiren

[Lasse Koskela]

SOA means service-oriented architecture and nothing more. Strictly speaking, the combination technologies you use doesn't matter.

[J. Acc.]

An argument can certainly be made that SOAs are completely technology independent, and that therefore Web Services are not an SOA requirement. That is especially true, since the term �Service-Oriented Architecture� existed long before Web Services surfaced. When discussing contemporary SOAs, however, it is pretty much an industry-standard expectation that you are talking about an application platform consisting (to a significant extent) of Web Services. Therefore, when we discuss SOA on this forum, I�d make the assumption that we are talking about a service-oriented architecture based on the use of Web services.

Having said all that, although vendor-technology independent, contemporary SOAs are expected to use certain open standards (that are, in turn, implemented via vendor-specific platforms). One of these standards certainly is WSDL, as this provides SOAs with a standardized interface definition format. While UDDI is becoming more common, it is not always an expected part of an SOA. Other standards worth mentioning are SOAP, and key XML standards, such as XML Schema.

To answer the original question, a WSDL does not have to be published via a UDDI registry in order for it to be considered part of an SOA.

[Pradeep bhatt]

Thomas

Is SOA used mainly for intergration of various applications? Also, is interoperablity a characteristics of SOA?

[Dhiren Joshi]

Thanks Thomas. That clarifies my doubt.
Since discovery is a requirement of SOA I was doubtful about UDDI for WSDL being necessary for webservices to stick to SOA.

[Lasse Koskela]

Originally posted by Pradeep Bhat:
Is SOA used mainly for intergration of various applications?

The architecture being service-oriented does make it easier to integrate applications (due to the granularity), but personally I wouldn't say that SOA is "used mainly for integration".

[J. Acc.]

By establishing a standardized communications framework, Web Services became a popular choice for enabling integration between disparate environments. Contemporary solutions can be supplemented with custom Web Services, and Web Services adapters can be plugged into legacy systems, and the result is an integration architecture that is open to any other Web Service-enabled applications. SOA is an environment built from the ground up with Web Services. This brings with it inherent integration benefits, but integration requirements would likely not be the sole reason for creating SOAs. However, since service-oriented solutions are built with open standards and design principles that emphasize interoperability, SOA services tend to be intrinsically interoperable. That would make interoperability a common trait of SOA. Have a look at the SOA definition that I plan to post tomorrow for more information about typical SOA characteristics.