are fault-replaces-message (FRM) and message-triggers-fault (MTF) equivalent

• From: Sanjiva Weerawarana <sanjiva@watson.ibm.com>
• Date: Sun, 2 Nov 2003 16:07:37 +0600
• To: <www-ws-desc@w3.org>
• Message-ID: <009f01c3a12a$da26a550$10266a20@lankabook2>

We currently have two fault patterns:

- FRM which can be used *after* the first message (since it doesn't
  make sense to start a MEP with a fault :-))
- MTF which can be associated with the first message even, but of
  course the fault follows the message since its the occurrence
  of the mesasage which triggers the fault.

Now, can we not just stick to MTF? FRM seems like just a special
case when the fault is associated with the first message but
defined with MTF.  

With FRM, we'd specify a simple in-out scenario with faults
as follows:
    <operation name='foo'>
        <input messageReference='A' body='x:e1'/>
        <output messageReference='B' body='x:e2'/>
        <outfault messageReference='B' details='f:f1'/>
        <outfault messageReference='B' details='f:f2'/>
    </operation>

If we switch the in-out to use MTF instead, this would look like
this:
    <operation name='foo'>
        <input messageReference='A' body='x:e1'/>
        <output messageReference='B' body='x:e2'/>
        <outfault messageReference='A' details='f:f1'/>
        <outfault messageReference='A' details='f:f2'/>
    </operation>

The only difference is the value of outfault/@messageReference.

I can't think of a case where an FRM scenario couldn't be expressed
using MTF thus.

So, shall we drop FRM and stick to MTF??

Sanjiva.

Received on Sunday, 2 November 2003 05:19:19 UTC