Re: [ws-rx] POTENTIAL NEW ISSUE: WS-RX policies not manifested on the wire

[Christopher B Ferris <chrisfer@us.ibm.com>]

Ashok,

I'm not certain that I would agree with the point you make as regards to 
the currently specified
wsrm:RMAssertion itself. Recall that a policy assertion is embodied in the 
QName of the assertion, not 
its content. Thus, one can tell, just by examining the messages themselves 
whether the WS-RM policy is
being followed, because messages will carry a wsrm:Sequence header 
element. The properties
or parameters (or what ever you want to call them) manifested by the child 
elements of the
wsrm:RMAssertion itself are of no consequence from the perspective of a 
given message (e.g. you
cannot examine a message out of context to determine whether the 
parameters are being
observed).

As for the DA assertions that have been discussed, I would agree, but we 
haven't yet determined
as a group that the DA will be manifested as a policy assertion, much less 
what it would mean with regards
to the protocol as manifested on the wire (if at all).

So, to restate: the wsrm:RMAssertion *is* manifested on the wire already 
by virtue of a wsrm:Sequence
SOAP header block in each message sent to a wsdl:port which carries that 
policy assertion. In the case where
the wsp:Optional="true" attribute is included in the wsrm:RMAssertion, 
then you can determine whether
or not the policy is being used by the presence or absence of the 
wsrm:Sequence SOAP header block.

Cheers,

Christopher Ferris
STSM, Emerging e-business Industry Architecture
email: chrisfer@us.ibm.com
blog: http://webpages.charter.net/chrisfer/blog.html
phone: +1 508 377 9295

Ashok Malhotra <ashok.malhotra@oracle.com> wrote on 08/01/2005 01:16:55 
PM:

> Title: WS-RX policies not manifested on the wire
> 
> Description:
> Issue i009 asks whether WS-RX should define policy assertions 
> to define various kinds of QoS properties for a message sequence.  This 
> certainly seems like a good subject for discussion.
> What worries is something related.
> 
> There is a tacit assumption that WS-RX policies will follow 
> WS-Policy (latest public version Sept. 2004).  This specification 
> does not state explicitly how to tell whether a message conforms to a 
particular 
> policy.  The assumption is that one can examine the headers in the 
> message and tell what policy is being followed.  Thus, the effect of 
> policies is manifested on the wire.
> 
> But neither the suggested QoS assertions nor the existing WS-RX 
> assertion that declares the retry-interval etc. will appear as message 
> headers.  So, how do we tell what policy is being followed? 
> Clearly, some other mechanism is needed.  One way is for messages to 
> carry the URI of the policy they adhere to.  Another is to define 
> headers in the start-sequence and sequence-started messages that 
indicate 
> policy information.
> I'm sure folks can come up with other good suggestions.
> 
> Justification:  See above.
> 
> Target: policy 
> 
> Type: design 
> 
> Proposal:  Needs discussion
> 
> Related issues: i009, i013
> 
> I can own this issue if the WG so desires.
> 
> All the best, Ashok
> 
>