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RE: Options on "Wrap" and "Unwrap" formats for WS-Eventing

From: Chou, Wu (Wu) <wuchou@avaya.com>
Date: Tue, 4 Jan 2011 17:00:34 -0500
Message-ID: <F81BDFA28AE48D4793E253362D1F7A740112B5C7@300813ANEX2.global.avaya.com>
To: "Gilbert Pilz" <gilbert.pilz@oracle.com>
Cc: <david.snelling@uk.fujitsu.com>, <public-ws-resource-access@w3.org>, <public-ws-resource-access-request@w3.org>, "Doug Davis" <dug@us.ibm.com>, "Li, Li (Li)" <lli5@avaya.com>
Gil,
 
According to WS-Eventing Second Last Call, Appendix A.2, and Appendix D
using Notification WSDL, point (4) is allowed. In particular, Appendix
D, WSDL for Standard Wrapped Delivery, it states "the event sink MUST
implement the following abstract WSDL ....", and the abstract WSDL
defined therein permits multiple events be sent in one notification
message.
 
We hope point (4) is there, as this feature can save a lot of processing
power, and significantly reduce the number of notifications that has to
be sent to the event sink while meeting the event delivery requirement.
 
- Wu Chou.


________________________________

From: Gilbert Pilz [mailto:gilbert.pilz@oracle.com] 
Sent: Tuesday, January 04, 2011 10:42 AM
To: Chou, Wu (Wu)
Cc: david.snelling@uk.fujitsu.com; public-ws-resource-access@w3.org;
public-ws-resource-access-request@w3.org; Doug Davis; Li, Li (Li)
Subject: Re: Options on "Wrap" and "Unwrap" formats for WS-Eventing


With regards to the final point (4) below; I don't think you can send
multiple events in a single Notification message.

~ gp

On 1/3/2011 1:25 PM, Chou, Wu (Wu) wrote: 

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	David,
	 
	Requiring event sink supports both wrap and unwrapped event
delivery may not make sense for the following reasons:
	 
	1. According to WS-E, it is the event subscriber/sink determines
the event delivering format (wrapped or unwrapped) in its subscription
message. It is not the other way around.
	 
	2. It is better for event source to meet the needs of various
types of potential event subscribers (one-to-many), vs. requiring every
event sink to implement additional options (many-to-one).
	 
	3. Event sinks typically have much less resources than event
source, and moreover, their options are limited by various application
environments, e.g. mobile, etc.
	 
	 
	Some of the reasons/benefits of using wrapped event sink are:
	 
	1. One interface for all types of events
	 
	2. Loosely coupled programming model
	 
	3. Good for event proxy applications, where it needs to handle
all types of events, including some new types of events that may
add/occur in the future.
	 
	4. Save power, using wrapped event sink - multiple events can be
delivered in one notification message, whereas using unwrapped event
sink - every single event requires one dedicated notification message
(critical for mobile and resource constrained devices).
	 
	Regards,
	 
	- Wu Chou.
	 
	Avaya Labs Research
Received on Tuesday, 4 January 2011 22:06:57 GMT

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