RE: [wsrf] Singleton Resource Pattern

[Rich Thompson <richt2@us.ibm.com>]

But with the stateless character of
web services, that UserName property would be shared by all users of the
web service. There may be some usefulness to that, but it becomes far more
useful when the web service interface fronts access to a multiplicity of
state, each storing such a property. 

To make this a concrete example, presume
the UserName property is really a reference to a field in a database. One
could provide a separate web service interface for each record within the
database, but it would be a much lighter (and frequently more useful) definition
if there was a single web service interface that had some well defined
means for indicating what record of the database was the target of the
current invocation. WSRP had this type of need and had to define a means
that is idiosyncratic to our protocol for passing the stateful reference.
Defining a standardized means by which infrastructure can take more of
the load for handling such references is one of the outcomes I would like
to see from the WSRF effort.

Rich Thompson
OASIS WSRP TC Chair

"Sedukhin, Igor S" <Igor.Sedukhin@ca.com>

07/12/2004 03:15 PM

To	Rich Thompson/Watson/IBM@IBMUS, <wsrf@lists.oasis-open.org>
cc
Subject	RE: [wsrf] Singleton Resource Pattern

Like I said, GetProperty would
mean for example:...
 
Web Service implements a UserName
property. Client sends a GetResourceProperty SOAP message with WS-Security
headers containing X.509 certificate. Web Service returns the UserName
after matching the certificate.

-- Igor Sedukhin .. (igor.sedukhin@ca.com)
-- (631) 342-4325 .. 1 CA Plaza, Islandia, NY 11788

 

---

From: Rich Thompson [mailto:richt2@us.ibm.com]
Sent: Monday, July 12, 2004 3:03 PM
To: wsrf@lists.oasis-open.org
Subject: RE: [wsrf] Singleton Resource Pattern


What would get/setProperty mean against the standard stateless character
of the base Web Services definition? Before these become useful, you need
some manner of modeling state. It seems to me the primary thrust behind
defining WSRF is having a standard definition of how to model such stateful
web services and as someone who has needed to idiosyncratically model state
within the WSRP protocol, I see a lot of value in that effort.

Rich Thompson
OASIS WSRP TC Chair

"Sedukhin, Igor S" <Igor.Sedukhin@ca.com>

07/12/2004 02:55 PM

To	Steve Graham/Raleigh/IBM@IBMUS
cc	<wsrf@lists.oasis-open.org>
Subject	RE: [wsrf] Singleton Resource Pattern

Then what value does the implied pattern add to the use case I have included?
  
Why does resource pattern have to depend on WS-Addressing, EPRs and customizations
of those? 
  
Why can't GetProperty/SetProperety be defined independently?

-- Igor Sedukhin .. (igor.sedukhin@ca.com)
-- (631) 342-4325 .. 1 CA Plaza, Islandia, NY 11788

---

From: Steve Graham [mailto:sggraham@us.ibm.com]
Sent: Monday, July 12, 2004 2:44 PM
To: Sedukhin, Igor S
Cc: wsrf@lists.oasis-open.org
Subject: RE: [wsrf] Singleton Resource Pattern


>It seems that whether it is an "implied resource" or an "implied
singleton" has nothing to do with GetResourceProperty (GetProperty
for that sake) operation. In >other words use of WS-Addressing does
not add any semantic value to the fact that one could retrieve a property
by sending a message to a service. 

Unfortunately, I disagree.  The implied resource pattern clarifies
a certain pattern relating a web service and a stateful resource. It is
important that this pattern is clarified to allow a single web service
to act as the Web services message processor for a plurality of stateful
resources. Therefore the pattern of the message is formed to disambiguate
which of the potentially many stateful resources is associated with the
message is very important. 

sgg 

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

"Sedukhin, Igor S" <Igor.Sedukhin@ca.com> 07/12/2004 11:56 AM

To:        Steve Graham/Raleigh/IBM@IBMUS, <wsrf@lists.oasis-open.org>       cc:               Subject:        RE: [wsrf] Singleton Resource Pattern

Steve, 
 
Your example was interesting. How about this one: 
 
Web Service implements a UserName property. Client sends a GetResourceProperty
SOAP message with WS-Security headers containing X.509 certificate. Web
Service returns the UserName after matching the certificate.
-- Is this a singleton or an implied resource pattern? One could claim
that there is a user resource, however this interaction does not use WS-Addressing
and moreover it would not be possible to build WS-RF qualified EPRs for
such interaction. 
 
The same use case could be modified to include UserDiskQuota property,
and the same argument would apply. 
 
It seems that whether it is an "implied resource" or an "implied
singleton" has nothing to do with GetResourceProperty (GetProperty
for that sake) operation. In other words use of WS-Addressing does not
add any semantic value to the fact that one could retrieve a property by
sending a message to a service.

-- Igor Sedukhin .. (igor.sedukhin@ca.com)
-- (631) 342-4325 .. 1 CA Plaza, Islandia, NY 11788