RE: [Bug 8286] New: description of Subscription End ambiguous

Since it is not possible to set up a successful subscription without honoring the filtering requirements, it makes sense to reject a subscription request with FilteringNotSupported fault.

But the availability of EndTo and support for SubscriptionEnd operation is not critical since the client can use GetStatus to find out the same. The current behavior allows clients to interact with services with different capabilities and vice versa; this is particularly useful in cases where the client and service do not live in a controlled environment. Attempting to match capabilities of clients that do or do not support EndTo with services that do or do not support SubscriptionEnd is quite complex and it makes the simple case very complex.

Thanks.

From: Doug Davis [mailto:dug@us.ibm.com]
Sent: Friday, January 08, 2010 12:32 PM
To: Ram Jeyaraman
Cc: public-ws-resource-access@w3.org
Subject: RE: [Bug 8286] New: description of Subscription End ambiguous


Why do we have a FilteringNotSupported fault then?  That's an optional element and an optional feature - yet we tell the subscriber that we don't support it.   By your first sentence we should silently ignore the Filter element if we don't support it, and we should ignore any unknown filter dialects - after all, they're optional.
Its not clear to me why we would not want to be user-friendly and let a subscriber know that what they asked for will not be adhered to.  We're not talking about an extension (which can be silently ignored w/o an mU=1 type of flag), we're talking about something that is defined by the base spec.

thanks
-Doug
______________________________________________________
STSM |  Standards Architect  |  IBM Software Group
(919) 254-6905  |  IBM 444-6905  |  dug@us.ibm.com<mailto:dug@us.ibm.com>
The more I'm around some people, the more I like my dog.

Ram Jeyaraman <Ram.Jeyaraman@microsoft.com<mailto:Ram.Jeyaraman@microsoft.com>>
Sent by: public-ws-resource-access-request@w3.org<mailto:public-ws-resource-access-request@w3.org>

01/08/2010 03:20 PM

To

Doug Davis/Raleigh/IBM@IBMUS, "public-ws-resource-access@w3.org<mailto:public-ws-resource-access@w3.org>" <public-ws-resource-access@w3.org<mailto:public-ws-resource-access@w3.org>>

cc

Subject

RE: [Bug 8286] New: description of Subscription End ambiguous







The notion of optionality implies duality, that is, SubscriptionEnd may or may not be supported. Further, such optional behavior should not affect normal processing.

>From a client subscriber perspective, optionality means the following:

1.        The Subscribe request containing an EndTo is accepted normally (that is, the subscription is NOT rejected because the event source cannot support SubscriptionEnd).
2.       It MAY receive a SubcriptionEnd if the event source is capable of sending SubscriptionEnd. No guarantees.

Based on this, I do not see a reason to fault a Subscribe containing an EndTo when the event source does not support SubscriptionEnd.  This allows the clients to function as intended irrespective of whether an optional behavior is supported or not by the service.

Thanks.

From: public-ws-resource-access-request@w3.org<mailto:public-ws-resource-access-request@w3.org> [mailto:public-ws-resource-access-request@w3.org]<mailto:[mailto:public-ws-resource-access-request@w3.org]> On Behalf Of Doug Davis
Sent: Tuesday, January 05, 2010 6:04 PM
To: public-ws-resource-access@w3.org<mailto:public-ws-resource-access@w3.org>
Subject: Re: [Bug 8286] New: description of Subscription End ambiguous


+1
http://lists.w3.org/Archives/Public/public-ws-resource-access/2010Jan/0009.html

thanks
-Doug
______________________________________________________
STSM |  Standards Architect  |  IBM Software Group
(919) 254-6905  |  IBM 444-6905  |  dug@us.ibm.com<mailto:dug@us.ibm.com>
The more I'm around some people, the more I like my dog.
Gilbert Pilz <gilbert.pilz@oracle.com<mailto:gilbert.pilz@oracle.com>>
Sent by: public-ws-resource-access-request@w3.org<mailto:public-ws-resource-access-request@w3.org>

01/05/2010 05:24 PM


To

Ram Jeyaraman <Ram.Jeyaraman@microsoft.com<mailto:Ram.Jeyaraman@microsoft.com>>

cc

"public-ws-resource-access@w3.org<mailto:public-ws-resource-access@w3.org>" <public-ws-resource-access@w3.org<mailto:public-ws-resource-access@w3.org>>

Subject

Re: [Bug 8286] New: description of Subscription End ambiguous











This is unacceptable because the Subscriber/Event Sink has no way of knowing if SubscriptionEnd is supported. It supplies an EndTo EPR, the Subscribe request succeeds, it gets some Notifications, then the subscription terminates unexpectedly (something it doesn't know about), then . . . nothing.

If support for SubscriptionEnd is really optional (something I don't remember to agreeing to - but my memory is shot), then it seems to me that we should:

1.) Define a new fault for a Subscribe message that includes an EndTo EPR along the lines of wse:SubscriptionEndNotSupported.

2.) Add a parameter to the wse:EventSource policy assertion that indicates support for SubscriptionEnd.

- gp

On 1/3/2010 9:17 AM, Ram Jeyaraman wrote:
I agree with this proposal except for the part where support for the SubscriptionEnd operation is required. During our earlier conversations, we determined that support for the SubscriptionEnd operation is optional for the Event Source. Given that, I suggest an amended proposal (change MUST to MAY):

"If the event source terminates a subscription unexpectedly and the wse:EndTo EPR was present in the Subscribe message for that subscription (see 4.1 Subscribe), the SubscriptionEnd message MAY be sent to the endpoint referenced by that EPR. The message MUST be of the following form:"

-----Original Message-----
From: public-ws-resource-access-notifications-request@w3.org<mailto:public-ws-resource-access-notifications-request@w3.org> [mailto:public-ws-resource-access-notifications-request@w3.org] On Behalf Of bugzilla@wiggum.w3.org<mailto:bugzilla@wiggum.w3.org>
Sent: Friday, November 13, 2009 1:44 PM
To: public-ws-resource-access-notifications@w3.org<mailto:public-ws-resource-access-notifications@w3.org>
Subject: [Bug 8286] New: description of Subscription End ambiguous

http://www.w3.org/Bugs/Public/show_bug.cgi?id=8286

         Summary: description of Subscription End ambiguous
         Product: WS-Resource Access
         Version: PR
        Platform: All
      OS/Version: All
          Status: NEW
        Severity: normal
        Priority: P2
       Component: Eventing
      AssignedTo: public-ws-resource-access-notifications@w3.org<mailto:public-ws-resource-access-notifications@w3.org>
      ReportedBy: gilbert.pilz@oracle.com<mailto:gilbert.pilz@oracle.com>
       QAContact: public-ws-resource-access-notifications@w3.org<mailto:public-ws-resource-access-notifications@w3.org>


Section 4.5 "Subscription End" starts with the following paragraph:

"If the event source terminates a subscription unexpectedly, SubscriptionEnd SOAP message SHOULD be sent to the endpoint reference indicated when the subscription was created (see 4.1 Subscribe). This endpoint reference MUST refer to an endpoint that supports the SubscriptionEndPortType portType. The message MUST be of the following form:"

The "SHOULD" in this sentence is ambiguous. Does it refer to the act of transmitting the message or does it refer to where the message is transmitted?
In both cases this should be a "MUST"; the SubscriptionEnd message MUST be transmitted, and it MUST be transmitted to the endpoint referenced by the EndTo EPR.

The sentence "This endpoint reference MUST refer to an endpoint that supports the SubscriptionEndPortType portType" is inappropriate and redundant; this is a constraint on the event sink, not the event source. This same constraint is already documented in the description of /wse:Subscribe/wse:EndTo.

Proposal: replace the above paragraph with the following:

"If the event source terminates a subscription unexpectedly and the wse:EndTo EPR was present in the Subscribe message for that subscription (see 4.1 Subscribe), the SubscriptionEnd message MUST be sent to the endpoint referenced by that EPR. The message MUST be of the following form:"


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