- From: Chou, Wu (Wu) <wuchou@avaya.com>
- Date: Tue, 31 Mar 2009 11:38:39 -0400
- To: "Gilbert Pilz" <gilbert.pilz@oracle.com>
- Cc: "Doug Davis" <dug@us.ibm.com>, "Asir Vedamuthu" <asirveda@microsoft.com>, "Bob Freund" <bob.freund@hitachisoftware.com>, "Li, Li (Li)" <lli5@avaya.com>, <member-ws-resource-access@w3.org>, <public-ws-resource-access@w3.org>, <public-ws-resource-access-request@w3.org>
- Message-ID: <F81BDFA28AE48D4793E253362D1F7A740112AAF8@300813ANEX2.global.avaya.com>
Gil, Good question. Using "out-of-band" event notification proxy is indicated by the Mode attribute in wse:Subscribe message from the subscriber. In this case, the subscriber indicates to use push_thru_proxy delivery mode in the Mode attribute in wse:Subscribe message without providing a proxy. In this case, the event source either has/knows an out-of-band proxy to meet the subscriber's requirement or it has to fault the subscription. - Wu Chou ________________________________ From: Gilbert Pilz [mailto:gilbert.pilz@oracle.com] Sent: Tuesday, March 31, 2009 2:13 AM To: Chou, Wu (Wu) Cc: Doug Davis; Asir Vedamuthu; Bob Freund; Li, Li (Li); member-ws-resource-access@w3.org; public-ws-resource-access@w3.org; public-ws-resource-access-request@w3.org Subject: Re: [Bug 6692] New: Remove Mode from the specification Wu, I'm confused by your "out-of-band-proxy" use case. If the agreement to use a proxy is truly "out of band", how can it appear in the wse:Subscribe message which is, be definition, a message sent from the Subscriber to the Event Source? - gp Chou, Wu (Wu) wrote: Doug, Many thanks for your comments. Let's separate the concerns and focus on each thread. 1) Keep Mode attribute of Delivery in WS-E: The use case is to establish legitimate critical applications based on Mode attribute of Delivery in WS-Eventing. It should not remove Mode from the WS-E specs, because it will affect and break the protocol used by existing applications and implementations. 2) EPR usage patterns: Let's definitely find sometime to discuss EPR extensions, and I will follow up with you on that. My thinking is: EPR can do many things but not everything. In our "out-of-band proxy" use case, the NotifyTo EPR is exactly the same for both cases, no matter it needs to go through the proxy or not, e.g. " http://avaya.com <http://avaya.com/> " . The out-of-band proxy can be opaque to the subscriber, e.g. a between enterprise IT 's agreement. The event source cannot differentiate two different event delivery modes just from the EPR in NotifyTo. And this is where the Mode attribute of Delivery in WS-E becomes critical. It is possible to put <ext:Proxy> as part of the NotifyTo EPR. But it is not all clear what event source should do to it. EPR alone does not provide the declarative semantics to event source on how it should treat <ext:Proxy>. For example, <ext:Proxy> should not be interpreted as reference parameters of the sink, because it is the EPR of the routing proxy which is a separate resource entity. By the opaque rule recommendation of EPR, event source should copy NotifyTo EPR and send the event back. But this will not work here. In order to deliver event correctly, the event source must do some "deep" semantic analysis of the EPR , and derive from the EPR the semantic action that it has to perform - must deliver the events through <ext:Proxy> to the sink. If it cannot do that, it must fault the subscription. This is where the Mode attribute of Delivery in WS-E is needed as described in our use case. Regards, - Wu Chou ________________________________ From: Doug Davis [mailto:dug@us.ibm.com] Sent: Monday, March 30, 2009 2:45 PM To: Chou, Wu (Wu) Cc: Asir Vedamuthu; Bob Freund; Li, Li (Li); member-ws-resource-access@w3.org; public-ws-resource-access@w3.org; public-ws-resource-access-request@w3.org Subject: RE: [Bug 6692] New: Remove Mode from the specification Wu, your use-case is a very interesting one. It shows one of the key points that I've been trying to make - this isn't specific to WS-Eventing. The need to send a message through a proxy (and have that proxy be defined by someone other than the sending endpoint - the subscriber in your case) could be just as meaningful to any EPR. For example, this could be needed for uses of wsa:ReplyTo, or the registrationEPR in WSTX, or the AcksTo EPR in RM. In all of these cases I believe this can be done by doing pretty much what you've done below. That is, provide the ultimate destination within the NotifyTo EPR but then use some extension mechanism to say "use a proxy". In this particular case I would suggest that you define an extension for the EPR structure - then this can be reused in _all_ WS-* specs. For example: <wse:NotfyTo> <wsa:Address> http://avaya.com </wsa:Address> <ext:Proxy> http://myproxy.com </ext:Proxy> </wse:NotifyTo> You can then also define a mU header that would require it to verify that it will adhere to the extension. IMO, this will not only satisfy your WS-Eventing needs but allow for this useful extension to be reused in lots of places. I'm not keen on creating one-off type of solutions just for certain WS-* specs - I think its a much better design to create reusable components. For example, should RM create a "use a proxy" extension too for its EPRs? Probably not when the above seems to work just fine for both specs. Its also worth pointing out that reusing the extensibility points of EPRs is actually a far cleaner design. In the example you gave it looks like the pub/sub code will need to understand this extension. While that is a valid choice, it would be much less work for developers to have this information encapsulated within the EPR itself. Then as this information is moved through a system only one data structure needs to be passed around - the EPR - and the pub/sub code might never actually need to know about this extension at all. In your model below they would need to pass around an EPR as well as the proxy information. And then when the next extension comes along they'll need to add yet another. That a potentially large code change each time. If, instead, they just knew about the EPR structure then no code changes will be needed except down at the transport layer of the product - where it should be. At that point they can examine all of the bits of the EPR (including the proxy info) and take whatever steps are necessary. This allows for an implementation to be designed such that it isolates itself from areas of concern that are of no consequence to it. thanks -Doug ______________________________________________________ STSM | Standards Architect | IBM Software Group (919) 254-6905 | IBM 444-6905 | dug@us.ibm.com The more I'm around some people, the more I like my dog. "Chou, Wu (Wu)" <wuchou@avaya.com> <mailto:wuchou@avaya.com> Sent by: public-ws-resource-access-request@w3.org 03/30/2009 02:12 PM To <public-ws-resource-access@w3.org> <mailto:public-ws-resource-access@w3.org> , <member-ws-resource-access@w3.org> <mailto:member-ws-resource-access@w3.org> cc "Asir Vedamuthu" <asirveda@microsoft.com> <mailto:asirveda@microsoft.com> , "Bob Freund" <bob.freund@hitachisoftware.com> <mailto:bob.freund@hitachisoftware.com> , "Li Li" <lli5@avaya.com> <mailto:lli5@avaya.com> Subject RE: [Bug 6692] New: Remove Mode from the specification +1 Asir: Many thanks for sharing your thoughts on this issue. And I attach one of our use cases of Mode in WS-E Delivery below. - Wu Chou Wu Chou, IEEE Fellow, Ph.D. | Director |Avaya Labs Research | AVAYA | 233 Mt. Airy Road| Rm. 2D48 | Basking Ridge, NJ 07920 | Voice/Fax: 908-696-5198 / 908-696-5401 | wuchou@avaya.com <blocked::mailto:wuchou@avaya.com> ------Use Case of MODE in WS-E Delivery ----- Here is a concrete use case where the subscriber requests the event source to push the event notifications through a proxy, obtained either through an out-of-band channel (not specified in the Subscribe request, e.g. the enterprise registers a special event notification proxy with the service provider) or dynamically specified in the Subscribe request. Certainly this behavior cannot be conveyed by the wse:NotifyTo. This critical use case thus justifies the need for the Mode attribute in WS-E Delivery. To indicate the use of an out-of-band proxy, the Subscribe request body looks like this: <wse:Subscribe> <wse:Delivery Mode="urn:push_thru_proxy" > <wse:NotifyTo>...</wse:NotifyTo> </wse:Delivery> </wse:Subscribe> To indicate the use of a dynamic proxy, the Subscribe request body looks like this: <wse:Subscribe> <wse:Delivery Mode="urn:push_thru_proxy" > <wse:Notifyto>...</wse:Notifyto> <ext:Proxy>...</ext:Proxy> </wse:Delivery> </wse:Subscribe> "Mode=urn:push_thru_proxy" cannot be put into the Delivery extension. This is because if the source cannot support "push_thru_proxy", it must fault as defined by Mode in Delivery, and the subscriber expects a standard wse:DeliveryModeRequestedUnavailable fault. And there is no standard WS-E fault for items in the Delivery extension. ---------- From: Asir Vedamuthu <asirveda@microsoft.com <mailto:asirveda@microsoft.com?Subject=RE%3A%20%5BBug%206692%5D%20New%3A %20Remove%20Mode%20from%20the%20specification&In-Reply-To=%253CD46B7A44F 5BD0C4A96D7D69E31C51D6B5098DCF4A7%40NA-EXMSG-C118.redmond.corp.microsoft .com%253E&References=%253CD46B7A44F5BD0C4A96D7D69E31C51D6B5098DCF4A7%40N A-EXMSG-C118.redmond.corp.microsoft.com%253E> > Date: Sun, 29 Mar 2009 19:59:23 -0700 To: "public-ws-resource-access@w3.org <mailto:public-ws-resource-access@w3.org?Subject=RE%3A%20%5BBug%206692%5 D%20New%3A%20Remove%20Mode%20from%20the%20specification&In-Reply-To=%253 CD46B7A44F5BD0C4A96D7D69E31C51D6B5098DCF4A7%40NA-EXMSG-C118.redmond.corp .microsoft.com%253E&References=%253CD46B7A44F5BD0C4A96D7D69E31C51D6B5098 DCF4A7%40NA-EXMSG-C118.redmond.corp.microsoft.com%253E> " <public-ws-resource-access@w3.org <mailto:public-ws-resource-access@w3.org?Subject=RE%3A%20%5BBug%206692%5 D%20New%3A%20Remove%20Mode%20from%20the%20specification&In-Reply-To=%253 CD46B7A44F5BD0C4A96D7D69E31C51D6B5098DCF4A7%40NA-EXMSG-C118.redmond.corp .microsoft.com%253E&References=%253CD46B7A44F5BD0C4A96D7D69E31C51D6B5098 DCF4A7%40NA-EXMSG-C118.redmond.corp.microsoft.com%253E> > Message-ID: <D46B7A44F5BD0C4A96D7D69E31C51D6B5098DCF4A7@NA-EXMSG-C118.redmond.corp.m icrosoft.com> <mailto:D46B7A44F5BD0C4A96D7D69E31C51D6B5098DCF4A7@NA-EXMSG-C118.redmond .corp.microsoft.com> Last week, on the WG conference call, I mentioned that we will provide some clarity on the concept of delivery mode (in WS-Eventing) and related use cases. Delivery mode [1] provides a subscriber with a mechanism to specify the means by which an event is delivered. Delivery mode is represented as a URI in a Subscribe message [2]. The semantics indicated by a delivery mode are: 1) Rules for the delivery of events a) Semantics and lifecycle of a Notification delivery b) Message Exchange Pattern used (One-way, Request-Response, etc.) and how the delivery mode binds to those Message Exchange Patterns c) Format of a response (if any) d) Configuration parameters or context data (if any) to support the Message Exchange Pattern e) Rules for the delivery or other disposition of faults generated during a Notification delivery 2) Delivery mode specific protocol information (if any) to guarantee interop 3) Supported delivery formats. Some portion of the above semantics are captured by an EPR, in a machine-readable form, but certainly not all. So, there is value added by a formal mechanism to indicate a delivery mode. The delivery mode is an extension point in WS-Eventing. The WS-Eventing specification defines a single built-in delivery mode, Push Mode. Other delivery modes may be important for external groups or other W3C Working Groups and are delegated to those groups. This is similar to SOAP Bindings. The W3C XML Protocol WG defined SOAP Protocol Binding Framework as an extension point and a concrete binding, SOAP HTTP Binding (is also identified using a URI [3]). Other groups defined SOAP bindings such as SOAP-over-JMS and SOAP-over-UDP. The DMTF WS-Management WG defined three new delivery modes [4] and these delivery modes have been widely adopted. Furthermore, based on the WS-RA WG charter [5], the WG deliverables need to satisfy the following requirements as well: 1) Charter scope - "Mechanisms to allow a subscriber to specify the means by which an event is delivered and the definition of a push-based delivery mode". 2) Charter scope - "In order to avoid disrupting the interoperability of existing implementations, WS-MetadataExchange<http://www.w3.org/Submission/2008/SUBM-WS-MetadataEx change-20080813/ <http://www.w3.org/Submission/2008/SUBM-WS-MetadataExchange-20080813/> >, WS-Transfer<http://www.w3.org/Submission/2006/SUBM-WS-Transfer-20060927/ <http://www.w3.org/Submission/2006/SUBM-WS-Transfer-20060927/> >, WS-Eventing<http://www.w3.org/Submission/2006/SUBM-WS-Eventing-20060315/ <http://www.w3.org/Submission/2006/SUBM-WS-Eventing-20060315/> > and WS-Enumeration<http://www.w3.org/Submission/2006/SUBM-WS-Enumeration-200 60315/ <http://www.w3.org/Submission/2006/SUBM-WS-Enumeration-20060315/> > should remain compatible with protocols and formats that depend on them, and offer a smooth migration path from the submission to the standard." We are aware of two dependant protocols - DPWS [6] (uses Push Mode) and WS-Management [4] (uses Push Mode and, as mentioned before, defines three new delivery modes). [1] http://www.w3.org/Submission/WS-Eventing/#Delivery_Modes <http://www.w3.org/Submission/WS-Eventing/#Delivery_Modes> [2] http://www.w3.org/Submission/WS-Eventing/#Subscribe <http://www.w3.org/Submission/WS-Eventing/#Subscribe> [3] http://www.w3.org/TR/2003/REC-soap12-part2-20030624/#http-bindname <http://www.w3.org/TR/2003/REC-soap12-part2-20030624/#http-bindname> [4] http://www.dmtf.org/standards/published_documents/DSP0226.pdf <http://www.dmtf.org/standards/published_documents/DSP0226.pdf> - Section 7 [5] http://www.w3.org/2008/11/ws-ra-charter.html#scope <http://www.w3.org/2008/11/ws-ra-charter.html#scope> [6] http://specs.xmlsoap.org/ws/2006/02/devprof/ <http://specs.xmlsoap.org/ws/2006/02/devprof/> We hope this helps. Regards, Asir S Vedamuthu Microsoft Corporation -----Original Message----- From: public-ws-resource-access-notifications-request@w3.org <mailto:public-ws-resource-access-notifications-request@w3.org?Subject=R E%3A%20%5BBug%206692%5D%20New%3A%20Remove%20Mode%20from%20the%20specific ation&In-Reply-To=%253CD46B7A44F5BD0C4A96D7D69E31C51D6B5098DCF4A7%40NA-E XMSG-C118.redmond.corp.microsoft.com%253E&References=%253CD46B7A44F5BD0C 4A96D7D69E31C51D6B5098DCF4A7%40NA-EXMSG-C118.redmond.corp.microsoft.com% 253E> [mailto:public-ws-resource-access-notifications-request@w3.org <mailto:public-ws-resource-access-notifications-request@w3.org?Subject=R E%3A%20%5BBug%206692%5D%20New%3A%20Remove%20Mode%20from%20the%20specific ation&In-Reply-To=%253CD46B7A44F5BD0C4A96D7D69E31C51D6B5098DCF4A7%40NA-E XMSG-C118.redmond.corp.microsoft.com%253E&References=%253CD46B7A44F5BD0C 4A96D7D69E31C51D6B5098DCF4A7%40NA-EXMSG-C118.redmond.corp.microsoft.com% 253E> ] On Behalf Of bugzilla@wiggum.w3.org <mailto:bugzilla@wiggum.w3.org?Subject=RE%3A%20%5BBug%206692%5D%20New%3A %20Remove%20Mode%20from%20the%20specification&In-Reply-To=%253CD46B7A44F 5BD0C4A96D7D69E31C51D6B5098DCF4A7%40NA-EXMSG-C118.redmond.corp.microsoft .com%253E&References=%253CD46B7A44F5BD0C4A96D7D69E31C51D6B5098DCF4A7%40N A-EXMSG-C118.redmond.corp.microsoft.com%253E> Sent: Thursday, March 12, 2009 8:37 AM To: public-ws-resource-access-notifications@w3.org <mailto:public-ws-resource-access-notifications@w3.org?Subject=RE%3A%20% 5BBug%206692%5D%20New%3A%20Remove%20Mode%20from%20the%20specification&In -Reply-To=%253CD46B7A44F5BD0C4A96D7D69E31C51D6B5098DCF4A7%40NA-EXMSG-C11 8.redmond.corp.microsoft.com%253E&References=%253CD46B7A44F5BD0C4A96D7D6 9E31C51D6B5098DCF4A7%40NA-EXMSG-C118.redmond.corp.microsoft.com%253E> Subject: [Bug 6692] New: Remove Mode from the specification http://www.w3.org/Bugs/Public/show_bug.cgi?id=6692 <http://www.w3.org/Bugs/Public/show_bug.cgi?id=6692> Summary: Remove Mode from the specification Product: WS-Resource Access Version: CR Platform: PC OS/Version: All Status: NEW Severity: major Priority: P2 Component: Eventing AssignedTo: public-ws-resource-access-notifications@w3.org <mailto:public-ws-resource-access-notifications@w3.org?Subject=RE%3A%20% 5BBug%206692%5D%20New%3A%20Remove%20Mode%20from%20the%20specification&In -Reply-To=%253CD46B7A44F5BD0C4A96D7D69E31C51D6B5098DCF4A7%40NA-EXMSG-C11 8.redmond.corp.microsoft.com%253E&References=%253CD46B7A44F5BD0C4A96D7D6 9E31C51D6B5098DCF4A7%40NA-EXMSG-C118.redmond.corp.microsoft.com%253E> <mailto:public-ws-resource-access-notifications@w3.org <mailto:public-ws-resource-access-notifications@w3.org?Subject=RE%3A%20% 5BBug%206692%5D%20New%3A%20Remove%20Mode%20from%20the%20specification&In -Reply-To=%253CD46B7A44F5BD0C4A96D7D69E31C51D6B5098DCF4A7%40NA-EXMSG-C11 8.redmond.corp.microsoft.com%253E&References=%253CD46B7A44F5BD0C4A96D7D6 9E31C51D6B5098DCF4A7%40NA-EXMSG-C118.redmond.corp.microsoft.com%253E> > ReportedBy: david.Snelling@UK.Fujitsu.com <mailto:david.Snelling@UK.Fujitsu.com?Subject=RE%3A%20%5BBug%206692%5D%2 0New%3A%20Remove%20Mode%20from%20the%20specification&In-Reply-To=%253CD4 6B7A44F5BD0C4A96D7D69E31C51D6B5098DCF4A7%40NA-EXMSG-C118.redmond.corp.mi crosoft.com%253E&References=%253CD46B7A44F5BD0C4A96D7D69E31C51D6B5098DCF 4A7%40NA-EXMSG-C118.redmond.corp.microsoft.com%253E> <mailto:david.Snelling@UK.Fujitsu.com <mailto:david.Snelling@UK.Fujitsu.com?Subject=RE%3A%20%5BBug%206692%5D%2 0New%3A%20Remove%20Mode%20from%20the%20specification&In-Reply-To=%253CD4 6B7A44F5BD0C4A96D7D69E31C51D6B5098DCF4A7%40NA-EXMSG-C118.redmond.corp.mi crosoft.com%253E&References=%253CD46B7A44F5BD0C4A96D7D69E31C51D6B5098DCF 4A7%40NA-EXMSG-C118.redmond.corp.microsoft.com%253E> > QAContact: public-ws-resource-access-notifications@w3.org <mailto:public-ws-resource-access-notifications@w3.org?Subject=RE%3A%20% 5BBug%206692%5D%20New%3A%20Remove%20Mode%20from%20the%20specification&In -Reply-To=%253CD46B7A44F5BD0C4A96D7D69E31C51D6B5098DCF4A7%40NA-EXMSG-C11 8.redmond.corp.microsoft.com%253E&References=%253CD46B7A44F5BD0C4A96D7D6 9E31C51D6B5098DCF4A7%40NA-EXMSG-C118.redmond.corp.microsoft.com%253E> <mailto:public-ws-resource-access-notifications@w3.org <mailto:public-ws-resource-access-notifications@w3.org?Subject=RE%3A%20% 5BBug%206692%5D%20New%3A%20Remove%20Mode%20from%20the%20specification&In -Reply-To=%253CD46B7A44F5BD0C4A96D7D69E31C51D6B5098DCF4A7%40NA-EXMSG-C11 8.redmond.corp.microsoft.com%253E&References=%253CD46B7A44F5BD0C4A96D7D6 9E31C51D6B5098DCF4A7%40NA-EXMSG-C118.redmond.corp.microsoft.com%253E> > The concept of Mode is redundant in the current version of the specification. All events can be thought of as being delivered. There is no actual definition of "Push Mode" and no other recommended modes. We even have a MakeConnection strategy to allow clients behind NATs to fetch events. Likewise, strategies for complex queuing and distribution are supportable without adding additional modes and are outside the scope of this specification. Proposal: Remove /s:Envelope/s:Body/*/wse:Delivery/@Mode from the specification and all references to Push Mode. A simple explanation of the delivery idea and a pointer to some of the techniques available will be needed. -- Configure bugmail: http://www.w3.org/Bugs/Public/userprefs.cgi?tab=email <http://www.w3.org/Bugs/Public/userprefs.cgi?tab=email> ------- You are receiving this mail because: ------- You are the QA contact for the bug. You are the assignee for the bug. Wu Chou, IEEE Fellow, Ph.D. | Director |Dialogue System Research | AVAYA | 233 Mt. Airy Road| Rm. 2D48 | Basking Ridge, NJ 07920 | Voice/Fax: 908-696-5198 / 908-696-5401 | wuchou@avaya.com <blocked::mailto:wuchou@avaya.com>
Received on Tuesday, 31 March 2009 15:39:49 UTC