RE: Infinite Loops and webservices

Congratulations for a really great example.  The wonderful thing about it is
the plausibility.

In my personal opinion, this sort of thing is exactly why the vision of
totally automated procurement via UDDI is EXTREMELY unlikely to take place
in the real world.  I cannot imagine a company that would be willing to
accept this kind of exposure, and I think that it would be very, very
difficult to convince real-world people (particularly the sort of person
that is involved in purchasing, who tend to be rather careful) that any
totally automated system could not fail in this sort of expensive way.

In practice, I think that mature EDI systems provide a useful model for what
is likely to happen.  In these systems the purchasing links are set up by
humans with explicit, highly controlled agreements.  The communication of
the transactions, then, proceeds automatically, but there are always people
involved at each step of the process.  The VAN acts like a mail service, not
a purchasing service.  The web services version of this replaces the
proprietary VAN's with communication via the web, but I think that the
business logic, which has been worked out as a result of tons of experience,
is likely to remain very similar or at most to evolve slowly.  The cost
savings comes from the efficiency of the communications and in the
standardization of the information transmitted so that it can be processed
easily into and out of backend systems, not from eliminating people entirely
from the process.

Incidentally, I talked to our EDI people about the scenario you suggest.
Apparently there is nothing in the EDI systems themselves that would
automatically prevent such a catastophe.  They found your scenario rather
amusing, in fact.  In the real world the protection comes from the fact that
a human being is involved in each transaction and, one hopes, would notice
that something was amiss after a while.

-----Original Message-----
From: Fraser David [mailto:david_a_fraser@hotmail.com] 
Sent: Wednesday, April 17, 2002 7:57 AM
To: www-ws-arch@w3.org
Subject: Infinite Loops and webservices


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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Received on Thursday, 18 April 2002 12:56:08 UTC