conclusion they came to is that Web services are simply the new
middleware. And middleware is something the OMG knows about. CORBA
Orbs sit at the heart of all Application Servers and most integration
done to date has been reliant on CORBA to translate between systems.
The OMG and its 800 members have learned a lot of lessons about
middleware over the last 12 years and there was complete agreement
on the enterprise qualities Web services need.
begin with, Web services is only a part of the picture, it is still
essential to consider existing integration platforms and the goal
is a seamless integration of all technologies being used. All agreed
that the continuing role of Java for tightly coupled and controlled
systems will be extended, allowing Java applications themselves
to integrate via Web services [Mike Connor, IBM].
we are quite focused today on the low level of Web services (SOAP,
UDDI, WSDL), it is critical that we raise the level of discussion
to the enterprise level because the hard part of enterprise integration
requires methods of managing the federated systems that are created
almost as a side effect of implementing Web services [Peter Herzum,
need insulation from rapidly changing standards built into their
modeling methods and development. Model based architectures of collaborating
service components should be designed using the OMG’s UML profile
for Enterprise Distributed Object Computing (EDOC). This enables
organizations to create a lasting development asset that can be
automatically mapped to the technology of the day using Model Driven
Architecture (MDA) [Cory Casanave, Data Access Technologies].
is key for large-scale use – and goes far beyond encryption and
signatures. We need to know that the service we contract with will
perform as expected, the identities involved, and that we can rely
on them. We need non-repudiation so the sender can’t deny that what
was delivered was in fact delivered [Bill Smith, Sun Microsystems].
crossing enterprise boundaries, legal issues need to be built in
so that you have enough evidence if you need to go to court. Legal
requirements demand clear statements of the nature of relationship
and boundaries - defining who owns what and what they have rights
to; as well as the degree of trust, expectations, liability risks
- in short – who’s accountable for what. These are essential for
quality of service agreements, for individual privacy, and for protection
of shared intellectual property [Matt Hettinger, Mathet Consulting].
this kind of comprehensive security we need legally binding contracts,
registries that can understand contracts, and implementations between
contracts rather than between end points [Mark Potts, Talking Blocks].
efforts at workflow management need to be expanded to enable the
orchestration of transactions within and across enterprises so that
controlled transactions can run for moments or months [Matt Hettinger,
holy grail of Web service to Web service management requires two
services talking to each other and achieving transactions through
document exchange with no humans involved. To enable such cross-enterprise
management of web services we need to provide visibility and control
with better dynamic selection and automatic negotiation of Web services
[Akhil Sahai, HP Labs].
agreed that in order for the Semantic Web to provide the ability
for machines to reason about and select appropriate Web services,
semantic interoperability is the major challenge. Semantics refers
to the meaning of terms and semantic drift tackles the fact that
terms continually change meaning. In the end the goal is to have
useful information you can process automatically with a program
– a machine readable Web [Hugo Haas, W3C].
matter how good XML tags are, how clean interfaces are, different
terms will be used to describe the same things. Ontologies will
provide a way to define language and rules based on agreements among
those sharing common services. Ontologies can be mapped to one another
and they facilitate conversations between agents on our behalf [Elisa
Kendall, Sandpiper Software].
management across federated systems and time will also require strong
semantics and ontologies that can map between vocabularies and understand
and manage emergent meaning within its context [Matt Hettinger,
as needed but not addressed were the heavy duty problems of dealing
with asynchronous version changes of services within and between
companies and the need to selectively expose services according
to role and authentication based on business rules [Gerald Edgar,
only controversy centered around emerging standards, particularly
those that the newly formed Web Services Interoperability organization
(WS-I) is interested in adopting or ignoring. …
recurring theme was that there is a huge danger that Web services
will become unmanageable. The more complex these requirements became,
the more apparent it was that a new trusted 3rd party
middleman might emerge. Web Services management platforms that can
manage versions, contracts, transactions, security, and semantics
will be essential [Mark Perreira, Talking Blocks].
were warned against trying to build their own Web services based
on today’s standards and encouraged to find tools that output Web
Services from higher-level development and analysis.
2002 by Infomaniacs