Fw: Question on XML versioning

Forwarded with permission.

Jon

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Date: Mon, 31 Oct 2005 12:41:20 -0600
From: 
Subject: Question on XML versioning
To: 
Cc: 

hi:
 
I am the current Co-chair of the XML task force in SEMI.  Your name was
given to me by Harvey Wohlwend from ISMI. I wrote some guide documents
to define the usage of namespaces in schema and wsdl files.  We defined
an interface between the factory software and equipment software using
XML, WSDL and SOAP called interface A or EDA (equipment data
acquisition).  Two years ago versioning seem a good idea and was
recommended by the majority of the experts I researched.  Today this
seems not a good idea because if you add a web service or delete one,
you have to change the interface or generate a new one because the
schema files now have a new version number.  It would be nice to keep
the interface backwards compatible but not sure how to do that with web
services and XML.  Do you have any suggestion whether we are doing the
right thing or maybe we should change and remove versioning from the
namespaces? How can you improve the interface without breaking the
clients since not everyone will be at the same rev level at anytime?
 
Gino 
 

Gino G. Crispieri
ISMI 

Intl. SEMATECH Manufacturing Initiative
Member Technical Staff
Office (512) 356-7547
Mobile (512) 751-3550