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Correlation parameter in an XMLP Block

From: Paul Denning <pauld@mitre.org>
Date: Fri, 30 Mar 2001 17:42:39 -0500
Message-Id: <5.0.2.1.0.20010330171005.04a8d1b0@mailsrv1.mitre.org>
To: xml-dist-app@w3.org
I've been thinking about Marwan's question of why the concept of causality 
is needed.

Its clear to me that it is needed, its just a matter of where you put it.

The XMLP Layer does not need it.

If the correlation id is passed down to the XMLP as a parameter of the 
XMLP_UnitData.send, what is the XMLP Layer supposed to do with it?
If it goes into an XMLP Block, then it should be the XMLP Module that 
constructs the Block (containing the correlation id).  The XMLP Layer does 
not look at or process the Block (or does it?)

If RPC is a module, and RPC requires causality and a correlation id, then 
an XMLP Block seems like the logical place to put the correlation id.

The XMLP Layer needs to provide a conduit for the upper layer modules to 
provide information to the lower layer bindings; otherwise, how would the 
lower layer binding (e.g., for HTTP) know when to send an HTTP response and 
what should go in it?

The "conduit" is something currently missing from the AM.  We need the 
concept of a "Context", which can be defined as
the runtime relationship between the XMLP Layer, the underlying bindings, 
and the upper layer modules.

Discussion?

Paul
Received on Friday, 30 March 2001 17:43:29 GMT

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