Composability: Do the Emperor's Clothes Fit? (RE: [xml-dev] Costs, benefits, and emperors with wardrobe malfunctions - was Re: [xml-dev] WS-Emperor naked?)

["Bullard, Claude L (Len)" <clbullar@ingr.com>]

I like the emphasis on composability in that overview.

http://lists.xml.org/archives/xml-dev/200203/msg01005.html

As Tim Bray noted, many started this odyssey as document 
geeks.  Some do other forms of composition, but composability 
is a tenet that one should contrast to interoperability and 
ask if the common understanding of interoperability is 
correct.  Composability assumes that portable 
data requires interoperability first because each part of 
the message assumes a reliable, working service which 
shares definitions if not sharing implementations.  One 
can compose nonsense quite easily with portable data 
if one composes statements the system can't reliably 
process.  But the web is NOT one system.  It is lots 
of little systems all in different lifecycles and 
the chaotic behaviors arise because of that.

Is the Emperor naked?  No.  Parts of the WS polyglot 
work reliably.  Is he stylishly attired?  Do we care? 
Probably not.   Is he overdressed?  Possibly.  So I 
ask about the WS-I and the basic profile.  One does 
expect the major companies to get beyond 'basics' 
ahead of the standards. The king and the peasant dress 
differently and the tailors charge accordingly 
and schedules a production run accordingly.

The emperor was naked because the tailors were dishonest, 
the emperor was gullible, and his subjects were 
politically correct.  That isn't a problem here. :-)

In short, the basics work.  WS are following the 
pattern of car manufacturing based on common parts. 
We may not get reliable power brakes as composable parts
until one or two manufacturers assemble and sell 
them for awhile.  So even if slow, the web services 
industry appears to be on track.   Again, in this 
period, we should emphasize specification with an 
eye to standardization.

A question of interest is when does composition 
create an insecure and unreliable service?  Well, 
one should choose their tailors wisely and if they 
promise magic, be dubious.  Once again, the web 
hypeMonster bites.

len


From: Dare Obasanjo [mailto:dareo@microsoft.com]

http://msdn.microsoft.com/library/en-us/dnwebsrv/html/wsoverview.asp