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Re: How to determine if an operation is synchronous

From: Sanjiva Weerawarana <sanjiva@watson.ibm.com>
Date: Wed, 23 Oct 2002 22:42:48 +0600
Message-ID: <030401c27ab3$3b6a1da0$8100a8c0@lankabook2>
To: "Ugo Corda" <UCorda@SeeBeyond.com>, "'Assaf Arkin'" <arkin@intalio.com>
Cc: <www-ws-arch@w3.org>

+1 to Ugo's position. AFAIK nothing in WSDL says that a request/resp
operation must be synchronous. All it says is that a message goes
and another comes .. that's it.

Sanjiva.

----- Original Message -----
From: "Ugo Corda" <UCorda@SeeBeyond.com>
To: "'Assaf Arkin'" <arkin@intalio.com>
Cc: <www-ws-arch@w3.org>
Sent: Wednesday, October 23, 2002 9:19 PM
Subject: RE: How to determine if an operation is synchronous


>
> You are still implying that a request/response operation must be
synchronous
> (even though it might be implemented by two asynchronous communications).
I
> am saying that the request/response operation itself can be asynchronous.
> Let's just agree to disagree.
>
> Ugo
>
> -----Original Message-----
> From: Assaf Arkin [mailto:arkin@intalio.com]
> Sent: Tuesday, October 22, 2002 10:08 PM
> To: Ugo Corda
> Cc: www-ws-arch@w3.org
> Subject: RE: How to determine if an operation is synchronous
>
>
> A synchronous operation can be performed by two asynchronous
communications.
> WSDL 1.1 allows you to specify a protocol binding that will use two
> separate, opposite direction, one message exchanged, asynchronous
> communications. The protocol would be asynchronous. The operation would be
> synchronous. The two do not stand in conflict.
>
> If you go back to my previous e-mail explaining the relation between node
A
> and node B, and how they 'synchronize' by performing such an operation,
you
> will see that nothing there says the message exchange is synchronous. In
> fact, if you use a synchronous protocol like HTTP you probably don't need
> all the lengthy time computation. You need that if you use an asynchronous
> protocol with a significant latency as proof that the operation is
> synchronous.
>
> arkin
>
> -----Original Message-----
> From: Ugo Corda [mailto:UCorda@SeeBeyond.com]
> Sent: Tuesday, October 22, 2002 9:51 PM
> To: 'Assaf Arkin'
> Cc: www-ws-arch@w3.org
> Subject: RE: How to determine if an operation is synchronous
>
>
> >From a WSDL operation definition you can determine that it is:
> >
> >- asynchronous  The operation involves a single message (one-way and
> >notification in WSDL 1.1)
> >- synchronous  The operation involves two messages in opposite
directions,
> >and indicates that it completes after receiving one and sending the other
> >(request-response and solicit-response in WSDL 1.1)
>
> Sorry, I disagree. I believe that a request-response operation can be
either
> synchronous or asynchronous. The author of the IBM series of articles on
> asynchronous Web services messages seems to have the same belief. Look at
> [1] (part 2 of the series), Pattern 2, Request/reply operations, where he
> says: "In this pattern, request and response are two messages defined
within
> a single request/reply operation and sent as two separate and unrelated
> transport-level transmissions."
>
> Ugo
>
>
> [1] http://www-106.ibm.com/developerworks/library/ws-asynch2/index.html
Received on Wednesday, 23 October 2002 12:45:01 GMT

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