[GRAAP-WG] exception handling in the current wsag spec

[Oliver Wäldrich]

Reviewing the latest spec we have recognized that the fault handling that
occures
if an greement could not be created (currently 1 fault) is not sufficient
for the
protocol. There are several issues related to this:

1. currently only the fault ResourceUnknownFault is defined. That fault
indicates 
   that the in the EPR referenced AgreementFactory (instance) is not known
to the
   server.

2. taking that in mind the createAgreement method should also define a 
   ResourceUnavailableFault indicating that the AgreementFactory instance is
known
   but it experiences problems at the time.

3. There should be a general CreateAgreementError that indicates that the
creation
   of an agreement failed. There was a ContinuingFaultError defined for
this, however 
   it looks to me that the naming of the error produced some problems in the
past and it
   was therefore removed. Perhaps it is feasible to reintroduce this general
error but 
   rename it. (e.g. AgreementCreationError)

4. It would be convenient to have some general error codes defined for
things that 
   can go wrong when creating agreements. I would suggest the following:

	<xs:complexType name="AgreementCreationErrorCodes">
		<xs:sequence>
			<xs:element name="GeneralError" type="xs:int"
fixed="0"/>	
			<xs:element name="TemplateUnknownError"
type="xs:int" fixed="1"/>	
			<xs:element name="InvalidAgreementOfferError"
type="xs:int" fixed="2"/>	
			<xs:element name="CreationConstraintsViolationError"
type="xs:int" fixed="3"/>	
		</xs:sequence>
	</xs:complexType>


Even if the public comment periode is over I would suggest having at least
one separate
exception in the schema that can be thrown if an agreement can't be created.


Regards,
Oliver Waeldrich


-----------------------------------------------------------------------
                          Oliver Wäldrich
  Fraunhofer-Institute for Algorithms and Scientific Computing (SCAI)
         Schloss Birlinghoven, D-53754 Sankt Augustin, Germany
             Tel: +49 2241 14 2830; Fax: +49 2241 14 42830
 
           CoreGRID Network of Excellence   www.coregrid.net
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