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I have
the general impression of the OGSA specs as the equivalence of
CORBA.
On the
topic of the WS-Resource Framework in particular, I've looked through the specs
and I think WS-Context could have been used, and it's unfortunate it
wasn't. I suppose the Resource Framework effort grew out of the Grid work
however so it has a completely independent origin.
I also
agree that I can't see a practical difference between context management in
transactions and the context management defined for the Resource
Framework.
It
would be nice to try to converge these things at some point and in some
organization - is that OASIS?
----- Original Message -----
Sent: Thursday, January 22, 2004 6:36
AM
Subject: RE: [ws-caf] WS-Resource
Framework
The specs and
presentations can be found at:
http://www.globus.org/wsrf
BTW... they are
trying hard to persuade people here at GlobusWORLD that the use of
WS-Addressing to identify a "stateful resource" (a resource whose state can
be represented as an XML document) is not the same as the use of context in
the case of WS-AtomicTransaction. Personally, I can't see the difference.
They are both ways to do message correlation and achieve stateful
interactions. The difference I see is that WS-Resource is a way to reason
about distributed objects.
I agree. It's the old
"you say tomatoes and I say tomatoes" thing. If it allows the unambiguous
representation of state within a specific arena (don't want to use the word
context here to avoid confusion), then it's contextualised. I haven't read the
specs. yet, but I assume that it's possible for the same end-point to
multiplex across many different states by different WS-Addressing
instances?
Now, whether people
are going to start building loosely-coupled, large-scale applications around
the concept of a stateful resource with a coupled identity (WS-Address +
local identifier) and a coupled interface (the interface of the Web Service
identified by the first part of the WS-Address) that will have to be
decided. Personally, I think it still looks like distributed objects but the
IBM folks over here assure me that they are not doing objects and are truly
service-oriented. People here may disagree with me. I guess only time will
tell whether this approach has any
benefits.
As usual it depends
who you talk to in IBM and elsewhere. Fairly obviously there are people in BEA
and MSFT who disagree. There are also people in IBM who think it's distributed
objects too.
In their
presentations, they are making the following distinctions (I am not going to
comment for now... I'll leave this up to you):
- "A truly
stateless service" (the set of operations that identify a Web
service)
- "A conversational
service"
- "A stateless
service that acts upon stateful resources"
Mark.
----
Mark
Little,
Chief Architect, Transactions,
Arjuna Technologies
Ltd.
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