[resend] Synchronous v/s Asynchronous, a WSA question, and few suggestions

Previous Topic Next Topic
 
classic Classic list List threaded Threaded
1 message Options
Reply | Threaded
Open this post in threaded view
|

[resend] Synchronous v/s Asynchronous, a WSA question, and few suggestions

Jonathan Marsh-2

Ram,

 

The Working Group tracked part of this mail as a comment against the spec, specifically:

 

b) Section 2.9.1 in the Core Language Spec states that "A Binding component that defines bindings for an Interface component MUST define bindings for all the operations of that Interface component".  Shouldnt a similar assertion be made regarding the Faults declared in the interface as well? i.e.  "A Binding component that defines bindings for an Interface component MUST define bindings for all the faults of that Interface component"

 

The WS Description Working Group tracked this issue as a CR081 [1].

 

As a result of this comment, the Working Group added a similar statement about faults, which is now implemented in the editor’s draft [2]

 

Unless you let us know otherwise by mid-January, we will assume you agree with the resolution of this issue.

 

[1] http://www.w3.org/2002/ws/desc/5/cr-issues/issues.html#CR081

[2] http://dev.w3.org/cvsweb/~checkout~/2002/ws/desc/wsdl20/wsdl20.html?content-type=text/html;%20charset=utf-8#Binding_details

 


From: [hidden email] [mailto:[hidden email]] On Behalf Of Ramkumar Menon
Sent: Wednesday, October 04, 2006 5:09 PM
To: [hidden email]
Subject: Synchronous v/s Asynchronous, a WSA question, and few suggestions

 

Gurus,

 

I am troubled by a few questions since a few days. Appreciate your comments in this matter.

 

a) What defines "synchronous" or "asynchronous" - Are this terms normatively defined in any related specification ?  Are these terms "adjectives" for message exchange patterns? 

b) Does "synchronous" interaction require the caller program to "block" on the response from the service ? [I know it really depends on what (a)'s answer is]

c) Can't a Request/Response transmission primitive [that wsdl 1.1 defines]  be asynchronous [thru wsdl extensions] ? The specification does not talk about the relationship between synchronicity and the type of the transmission primitive. So I assume this does not violate the conformance requirements.

d) Is it correct if I state that synchronicity and asynchronicity of an interaction cannot be defined at the abstract level of a service definition and depends purely on the transport bindings being used ? [or if the user employs extensions for the operation in the abstract portion of the WSDL] 

e) What is the relationship between the transport specified in the WSDL 1.1 Bindings and the ReplyTo/FaultTo requirements that are imposed on the service ? - confusing question, aint it ? :-)

Let me explain with an example.

  I define a WSDL 1.1 service with a portType with a request/response/fault operation. I define WS-A headers for each of the input, output and fault in the binding section.  I wish to return faults from this operation to a FaultTo endpoint that is different from the ReplyTo endpoint. Shouldnt it be possible to send messages to the FaultTo endpoint on a different transport ? [ i.e. Lets say I wish to send faults to an Email Address]. Question is as follows - If so, would this require separate bindings for the operation to be defined within the WSDL ?". If this answer to this question is "yes", then, since transports are specified at the operation level, this would require two bindings, one for http and one over smtp.  And in the second binding, what does it mean to specify the information for the input and output - they are unused. :-)  I am gonna get killed for making this assumption , but I am really confused on this last point - I maybe wrong here. Or maybe WSDL 1.1 is tough to gel in with WSA requirements without relying on some extension mechanism.

 

Few other points:-

a) I noticed that Figure 2-1 [xml infoset] in Section 2.2.1 in WSDL 2.0 primer states that an interface should have 1-* number of operations. This should be changed to 0-*.[since there could be interfaces with zero operations, for instance, an interface that just defines faults]

b) Section 2.9.1 in the Core Language Spec states that "A Binding component that defines bindings for an Interface component MUST define bindings for all the operations of that Interface component".  Shouldnt a similar assertion be made regarding the Faults declared in the interface as well? i.e.  "A Binding component that defines bindings for an Interface component MUST define bindings for all the faults of that Interface component"

c) An interesting thought [on wsdl 2.0] - Why cant faults be global to a description - I have a scenario where the wsdl defines two interfaces - one for reserving flight tickets for the travel, and one for making hotel reservations for the travel.Each of these interfaces are served by two separate endpoints [lets say, outsourced to two different organizations]

Both of them throw a fault namely "CreditCardAuthorizationFault" and a "InsufficientFundsFault". Why cant this fault be declared globally, and referenced within each of the interfaces ? [I'm being too impractical, aint I ? :-) ] - But would definitely appreciate an explanation to this point.

 

rgds,

Ram