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Re: Infinite Loops and webservices

From: David Booth <dbooth@w3.org>
Date: Thu, 18 Apr 2002 16:45:21 -0400
Message-Id: <5.1.0.14.0.20020418160331.028e96a8@localhost>
To: www-ws-arch@w3.org
Whenever ANYTHING is automated, the automation can amplify the damage 
caused by an error.  In this case, the problem can only occur if one of the 
companies is willing to AUTOMATICALLY sell widgets (effectively) below 
cost.  (If the retail sale price is equal to the wholesale purchase price, 
then the sale is still effectively below cost because of overhead.)  It 
would be stupid for any company to automatically do this without having 
some kind of mechanism for limiting the volume.  Whenever a store offers a 
"loss leader" (e.g. "bananas 2 cents a pound") it always limits the 
quantity ("limit one per customer").

In short, this kind of mistake can be made, but it is not fundamentally 
different from many other mistakes that you can make whenever you automate 
something.

At 12:56 PM 4/16/2002 -0400, Fraser David wrote:
>I have an idiot question:
>Given how loosely coupled webservices and their clients can be and the 
>high degree of dynamicity(?) there can be in choosing webservices could it 
>be possible that infinite loops could occur between companies?
>e.g.
>Company X manufactures widgits
>Company Y manufactures widgits
>Company Z is a retailer of widgits
>
>Company Z runs out of widgits and through dynamically searching through a 
>UDDI registry determines that Company X has the best price for widgets. 
>Company X does not have enough widgets to immediately fulfill the order 
>but instead informing the client of this Company X's webservice has been 
>programmed to search for another widget manufacturer (Company Y) in the 
>UDDI registry and buy the widgets at
>cost thereby keeping the business of Company Z. Company Y only has 1 
>widget left. Unfortunately its webservice has been programmed to search 
>for the cheapest widget manufacturer in the UDDI registry if it does not 
>have enough widgets to complete a sale. As Company X has the
>cheapest widgets it invokes it's webservice. This completes the loop and 
>Company X and Y end up ordering 6 bazillion widgets from each other to 
>fulfill Company Z's need for only a couple of widgets.
>
>D.
>
>
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David Booth
W3C Fellow / Hewlett-Packard
Telephone: +1.617.253.1273
Received on Thursday, 18 April 2002 16:44:57 GMT

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