Delivered-To: dfarber+@xxxxxxxxxxxxxxxxxx
Date: Mon, 29 Sep 2003 13:09:12 -0400
From: noah_mendelsohn@xxxxxxxxxx
Subject: Site Finder Confuses SOAP Implementations
To: Dave Farber <dave@xxxxxxxxxx>
(This is my first attempt to submit to IP...if this is not the appropriate
way to go about it, please accept my apologies. Thank you.)
Dave,
As many of your readers are probably aware, SOAP [1,2] is an XML-based
protocol for connecting applications over the Web. Implementors of SOAP
engines maintain a mailing list called "soapbuilders", on which they
discuss implementations and debug interoperability problems.
According to soabuilders postings over the past couple of days [3,4], the
Verisign Site Finder service is causing trouble for at least some SOAP
implementations. This is not surprising, I suppose, since Site Finder
makes the erroneous assumption that users of HTTP are invariably human
beings sitting at a Web browser. In fact, HTTP is the preferred protocol
for most document-based interactions on the Web, including
application-to-application or machine-to-machine, and SOAP layers on HTTP.
In general, SOAP implementations would want redirects only in the
particular case that a web service had truly moved from one DNS address to
another. I suspect that most current users of SOAP don't employ such
redirects, and that early SOAP implementations probably don't support them
gracefully. In any case, it's very unlikely that a SOAP implementation
accessing a web service using a mis-spelled URL would benefit from a
redirect to a site such as Site Finder.
I have no direct involvement with the implementations discussed in the
soapbuilders postings, and have not observed the Site Finder/SOAP problem
first hand, but I thought IP readers might be interested. Thank you.
Noah
[1] http://www.w3.org/TR/soap12-part1/
[2] http://www.w3.org/TR/soap12-part2/
[2] http://groups.yahoo.com/group/soapbuilders/message/9475
[3] http://groups.yahoo.com/group/soapbuilders/message/9476
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Noah Mendelsohn Voice: 1-617-693-4036
IBM Corporation Fax: 1-617-693-8676
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