- From: Katy Warr <katy_warr@uk.ibm.com>
- Date: Mon, 23 Mar 2009 16:12:21 +0000
- To: ashok.malhotra@oracle.com
- Cc: "public-ws-resource-access@w3.org" <public-ws-resource-access@w3.org>
- Message-ID: <OF88FAA016.9F12817D-ON80257582.0054F328-80257582.00590542@uk.ibm.com>
Hi Ashok
I'm sure that I'm mis-communicating and not you! I'm still not sure
where you would attach policy to an implicit operation in the EPR without
some sort of pattern.
Perhaps a real-ish example could help us here: Consider attaching
imaginary SecurityPolicy (symmetric binding+Signed supporting tokens) to
an Eventing.subscribe message.
How do you envisage that example looking in EPR metadata? I think that we
could potentially use a similar pattern to that suggested in the issue but
applied to the EPR, giving (something along the lines of) this:
<wsa:Metadata>
...
<wsp:Policy>
<wsra:WS-Eventing>
<wsra:SubscribePolicy>
<wsp:Policy>
<wsp:All>
<sp:SymmetricBinding>
...
</sp:SymetricBinding>
<SignedSupportingTokens>
...
</SignedSupportingTokens>
</wsp:All>
</wsp:Policy>
</wsra:SubscribePolicy>
</wsra:Eventing>
<wsra:WS-Mex ws-mex-all ='false' />
</wsp:Policy>
...
</wsa:Metadata>
I'm wondering whether we could find a pattern for implicit operation
policy (e.g. like the pattern above - but not necessarily that one) and
apply it to both policy passed in WSDL and EPRs?
Many thanks
Katy
From:
ashok malhotra <ashok.malhotra@oracle.com>
To:
Katy Warr/UK/IBM@IBMGB
Cc:
"public-ws-resource-access@w3.org" <public-ws-resource-access@w3.org>
Date:
23/03/2009 14:05
Subject:
Re: [Bug 6721] New: Attaching policy to implicit operations
Hi Katy:
We may be miscommunicating but let me try and be a bit more explicit in
what I was proposing.
The EPR has the following structure:
<wsa:EndpointReference>
<wsa:Address>xs:anyURI</wsa:Address>
<wsa:ReferenceParameters>xs:any*</wsa:ReferenceParameters>?
<wsa:Metadata>xs:any*</wsa:Metadata>?
</wsa:EndpointReference>
Now suppose we wanted to say that the endpoint supports WS-Eventing and
WS-Mex but does not support the ws-mex-all dialect. (Just an
illustration). Then the Metadata section within the EPR could look like
<wsa:Metadata>
...
<wsp:Policy>
<wsra:WS-Eventing/>
<wsra:WS-Mex ws-mex-all ='false' />
</wsp:Policy>
...
</wsa:Metadata>
Where wsra:WS-Eventing and WS-Mex are policy assertions we define that
indicate various properties of the endpoint. By defining these
specialzed assertions we can write policies that apply to only a single
operation supported by the endpoint.
All the best, Ashok
Katy Warr wrote:
>
> Hi Ashok,
>
> I agree that it should be possible to pass the policy in the EPR.
> However, this isn't quite answering this issue because it doesn't
> give a syntax for attaching the policy to the implicit operation (as
> the scope of the policy in the EPR metadata is the endpoint). We
> could state that the implicit operations simply inherit the endpoint's
> policy but this approach has drawbacks (as mentioned in the issue).
>
> Theoretically, implicit operations' policies could be passed in WSDL
> or EPR (and it would be nice to allow both), but in both cases we'd
> need a way to indicate that the policy is associated with the implicit
> operation (rather than the endpoint and all its operations).
>
> Incidentally, the WS-Mex GetMetadata verb adds an additional
> complexity to the implicit operation problem because there is a
> chicken-egg situation that means that there's no way to get the WSDL:
> http://www.w3.org/Bugs/Public/show_bug.cgi?id=6463. Passing policy
> in the EPR could be a solution to this problem ... but there is still
> the question as to how to associate the policy with the actual
> GetMetadata operation.
>
> Best regards,
> Katy
>
>
> From: ashok malhotra <ashok.malhotra@oracle.com>
> To: "public-ws-resource-access@w3.org"
> <public-ws-resource-access@w3.org>
> Date: 19/03/2009 18:59
> Subject: Re: [Bug 6721] New: Attaching policy to implicit
operations
>
>
> ------------------------------------------------------------------------
>
>
>
> Our proposal for attaching policy to endpoints is to include it in the
> metadata section of the EPR.
> See http://www.w3.org/Submission/WS-PAEPR
> All the best, Ashok
>
>
> bugzilla@farnsworth.w3.org wrote:
> > http://www.w3.org/Bugs/Public/show_bug.cgi?id=6721
> >
> > Summary: Attaching policy to implicit operations
> > Product: WS-Resource Access
> > Version: PR
> > Platform: PC
> > OS/Version: Windows XP
> > Status: NEW
> > Severity: normal
> > Priority: P2
> > Component: All
> > AssignedTo: public-ws-resource-access-notifications@w3.org
> > ReportedBy: katy_warr@uk.ibm.com
> > QAContact: public-ws-resource-access-notifications@w3.org
> >
> >
> > There are a number of issues already open addressing how we attach
> policies to
> > indicate that an endpoint supports virtual (implicit) operations and
the
> > flavour/extent of that support. For example,issue 6403
> > http://www.w3.org/Bugs/Public/show_bug.cgi?id=6403 describes policy
> to indicate
> > that an endpoint supports enumeration and there are similar issues
> open for the
> > other specs (6402,6406, 6407).
> >
> > These issues do not discuss how policy should be attached to the
virtual
> > operation (i.e. one that does not appear in WSDL) itself. They also
> don't
> > address what policy should be applied to the virtual operations by
> default.
> > One option for default behaviour might be to default to the policy
> of the
> > endpoint, but this poses problems as many policies are applied at
> > operation/message level (and therefore are not available at the
> endpoint).
> >
> > There are a number of possible solutions that we might adopt to
> solve this
> > problem. I suggest that we choose a pattern and re-use that across
> all the
> > specs for simplicity and consistency.
> >
> > For example, here's a potential pattern:
> >
> > <wsp:Policy>
> > ... <lots of policy for the endpoint>
> >
> > <wsra policy indicating wsra spec support>
> > ...
> >
> > <wsra:VirtualOperationPolicy>
> > ...
> > </wsra:VirtualOperationPolicy>
> >
> > </wsra policy indicating wsra spec support>
> >
> > </wsp:Policy>
> >
> > The VirtualOperationPolicy defines the policy for the implicit
> operations
> > relating to the wsra spec support.
> >
> > For example, the above pattern applied to eventing MIGHT look
> something like
> > this:
> >
> > <wsev:WSEventingSupported ...>
> > <wsp:Policy>
> > ...
> >
> > <wsev:subscribeOperationPolicy>
> > ... policies such as security policy to attach to subscribe
> request ...
> > </wsev:subscribeOperationPolicy>
> >
> > </wsp:Policy>
> > </wsev:WSEventingSupported>
> >
> > If we agree on a pattern to try, the next step might be to take some
> real
> > examples (e.g. security policy) in order to check that the pattern
> works prior
> > to applying it across the specs.
> >
> > This issue is also related to
> > http://www.w3.org/Bugs/Public/show_bug.cgi?id=6694 which asks when
> operations
> > do/don't appear in the WSDL.
> >
> > It's probably best for us to address the other policy issues and
> 6694 before
> > this one - but this is an important issue as lack of clear
> specification in
> > this area will prevent interoperability and make life hard for
> implementers.
> >
> >
> >
>
>
>
>
>
>
> ------------------------------------------------------------------------
>
> /
> /
>
> /Unless stated otherwise above:
> IBM United Kingdom Limited - Registered in England and Wales with
> number 741598.
> Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6
> 3AU/
>
>
>
>
>
>
Unless stated otherwise above:
IBM United Kingdom Limited - Registered in England and Wales with number
741598.
Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 3AU
Received on Monday, 23 March 2009 16:15:04 UTC