Re: [wsn] Multiple endpoints in IRP?

[David Hull <dmh@tibco.com>]

Load-balancing seems like a likely counterexample.  One could imagine an NP delegating actual management to several physical SM servers.  This would be particularly likely if refreshes were expected to somewhat frequent, meaning that a subscription might be refreshed several times during its lifetime.  There would then be several times as many refresh messages as subscription messages, justifying multiple SM servers.

Vambenepe, William N wrote:

It's not in any way required by the spec. Because of how people might
choose to implement it I wouldn't be surprised if it is often the case
that all the subscription created by one NotificationProducer share the
same address element in their EPR, but as far as the spec is concerned
it is irrelevant.

Regards,

William

-----Original Message-----
From: Patil, Sanjay [mailto:sanjay.patil@sap.com] 
Sent: Thursday, August 05, 2004 3:49 PM
To: Vambenepe, William N; Steve Graham; David Hull
Cc: wsn@lists.oasis-open.org
Subject: RE: [wsn] Multiple endpoints in IRP?


I have a related question here  --

Does the IRP require that multiple WS Resources of the same type share a
single endpoint? For example, is it required that the EPRs for all the
Subscriptions created by a NotificationProducer have the same endpoint
address. Or would it simply be considered as a common practice (isn't
that really a pattern)?

Thanks,
Sanjay

  

-----Original Message-----
From: Vambenepe, William N [mailto:vbp@hp.com]
Sent: Thursday, Aug 05, 2004 2:59 PM
To: Steve Graham; David Hull
Cc: wsn@lists.oasis-open.org
Subject: RE: [wsn] Multiple endpoints in IRP?


(with my TC member hat on, not my chair hat)

The statement you pointed out is really just a reinforcement of the 
rules of the IRP. And, as Steve says, it doesn't imply any capability 
to address WS-Resources as groups. Or did I misunderstand your 
question David?

William


________________________________

From: Steve Graham [mailto:sggraham@us.ibm.com]
Sent: Thursday, August 05, 2004 1:43 PM
To: David Hull
Cc: wsn@lists.oasis-open.org
Subject: Re: [wsn] Multiple endpoints in IRP?



hi David: 
I would think that one of our WSDM colleagues could comment further.
But from my read of the statement you quoted from WSDM MUWS, it was 
simply observing that a manageability endpoint (eg a Web service
endpoint) may be the front end for multiple resources.  Therefore the 
IRP must be used to identify any single one of those resources.  I 
didn't get the read that there was any capability implied to access a 
group of more than one resource with a single EPR.  This is not 
possible from what I understand of WS-Addressing.

sgg

++++++++
Steve Graham
(919)254-0615 (T/L 444)
STSM, On Demand Architecture
Member, IBM Academy of Technology
<Soli Deo Gloria/>
++++++++




	David Hull <dmh@tibco.com>

08/05/2004 04:14 PM

	        
        To:        wsn@lists.oasis-open.org 
        cc:         
        Subject:        [wsn] Multiple endpoints in IRP?



While reading through WSDM MUWS, I ran across this interesting
statement:

"If the manageability endpoint corresponds to a variable number (zero 
or

more) of manageable resources, then the WSRF Implied Resource Pattern 
MUST be followed.  This means that the element(s) listed in the 
ReferenceProperties of a WS-Resource qualified EPR must be included in
    

the header of messages sent to such manageability endpoints."

This seems to imply a WS-Address with multiple ReferenceProperties 
elements, one for each EPR.

Does the IRP allow for multiple resources to be addressed as a group?
Does this have to be done via repeated ReferenceProperties elements, 
or could one give a predicate instead, or bake something magic into 
the Address URI?

I realize that the IRP is in a fluid state at the moment, but I'd be 
interested to know current thinking.  Is this the sort of issue the 
WSRP

subgroup is trying to address?