Mark McKeown <zzalsmm3@nessie.mcc.ac.uk> wrote on 08/31/2005 09:53:39 AM:
Hi Tom,
If so, then a unique AbstractName is needed in order to accurately resolve EPRs, especially considering the potential service migration.
I think that AbstractName is certainly one approach to solving this problem. Remember that ReferenceParameters are used to provide
information
to the RECEIVER(wsa:to) to disambiguate the resource for dispatch.
I am confused by this - according to the WS-Addressing working group ReferenceParameters are designed to support stateful interactions (similar to the use of cookies with HTTP) - not to identify resources. They CAN be used to identify resources but this is not best practice according to the working group.
Ok, so what is confusing you is the use of 'disambiguate the resource for dispatch'. So, change that sentence to: Remember that ReferenceParameters are used to provide required information to the RECEIVER(wsa:to) interaction. And the spec ultimately wound up saying: [reference parameters] : xs:any (0..unbounded). A reference may contain a number of individual parameters that are associated with the endpoint to facilitate a particular interaction. Reference parameters are namespace-qualified element information items that are required to properly interact with the endpoint. Reference parameters are provided by the issuer of the endpoint reference and are assumed to be opaque to other users of an endpoint refernce. The binding of reference parameters to messages depends upon the protocol binding used to interact with the endpoint - Web Services Addressing 1.0 - SOAP Binding[WS-Addressing-SOAP] describes the default binding for the SOAP protocol. and additionally says: 2.3 Endpoint Reference Comparison This specification provides no concept of endpoint identity and therefore does not provide any mechanism to determine equality or inequality of EPRs and does not specify the consequences of their equality or inequality. However, note that it is possible for other specifications to provide a comparison function that is applicable within a limited scope.
see http://www.w3.org/2002/ws/addr/wd-issues/#i001 and http://lists.w3.org/Archives/Public/public-ws-addressing/2004Dec/0051
thanks Mark