[wsia] RE: [wsrp] WSXL paper update

From
Eilon Reshef <>
Date
2002-04-12T21:13:56+00:00
ID
000101c1e267$ae3f08c0$ed0aa8c0@eilon
Thread
[wsia] RE: [wsrp] WSXL paper update
Title: Message

Thanks. 

 

BTW, I really liked the new 
write-up.

 

Another question or two (I hope it's 
OK...):

 

The getServiceDocument and hasPortType seem to be very 
"generic" in the sense that they could apply to essentially every Web Service 
(not necessarily a WSIA one). Pragmatists may even argue that it's somewhat of a 
more sensible model than the registry model (UDDI) (especially the 
getServiceDocument one, and especially if it can be provided via a simple HTTP 
GET request). Do those definitions come from other IBM work (is this related to 
IBM's dynamic Web Services invocation stuff?)? Do you know if such an approach 
has been actively promoted anywhere else in the Web Services "world"? 

 

How do you think that WSIA should handle this topic - 
should we define such interfaces and state that they should be propagated to the 
lower parts of the stack? Should we wait for the lower parts of the stack to 
support it (I hope not)?

 

Any particular thoughts on the lifecycle management 
along the same lines? Were you guys aware of any "generic" Web Services notion 
that captures stateful Web Services? Should we define those interfaces and 
basically explicitly note that we expect the lower part of the stack to adapt or 
refine them? Or maybe are we (WSIA) the right part of the 
stack?

 

  

  
-----Original Message-----
From: Rich Thompson 
  [mailto:] 
Sent: Friday, April 12, 2002 3:55 
  PM
To: Eilon Reshef
Cc: ; 
  
Subject: RE: [wsrp] WSXL paper 
  update

  
The framework does assume the Producer has a stateful service. 
  The case of 
a stateless service can be indicated by 
  returning null from createInstance 
() or possibly via 
  setting of some read-only property (may even just be in 
the property schema. A Producer that acts in a stateless manner 
  doesn't 
have a different interface, it ignores the 
  incoming handle and the values 
in the propertyList can 
  be viewed as scoped to the request. It would be 
appropriate to throw a fault on calls to setProperties() as 
  well. 

  
It is an interesting question as to whether there is a WSIA 
  Property schema 
that a property document must conform 
  too as well as the Producer's schema. 
The flavor of 
  discussions has been toward resisting such a restriction with 
the understanding that it may become necessary for the more advanced 
  use 
cases. 

  
The Adaptation Description Language has been going through a 
  significant 
rewrite as the fundamental nature of 
  properties has evolved and this 
rewrite is not 
  reflected in this version. The current definition has the 
URI indicated as metadata for the service and there has been 
  discussion 
about allowing this to be more dynamic both 
  to cover the cases you site and 
those where different 
  business partners are provided with different 
authorizations to customize the output. 

  
                                                                                                                
  
                      
  Eilon 
  Reshef                                                                              
  
                      
  <eilon.reshef@webc        
  To:       Rich 
  Thompson/Watson/IBM@IBMUS                        
  
                      
  ollage.com>               
  cc:       
                               
  
                                                
  Subject:  RE: [wsrp] WSXL paper 
  update                          
  
                      
  04/12/2002 
  03:32                                                                          
  
                      
  PM                                                                                        
  
                                                                                                                
  
                                                                                                                
  

  
Looks very interesting. I had some questions regarding the 
  WSXL document: 

  
Am I correct in my understanding that the framework assumes 
  that the 
Producer has a stateful service (portlet) 
  end, that can store and return 
the property values? Is 
  this something you have been debating internally? 
Did 
  you also consider a hybrid model in which the Producer doesn't have to 
  
store the property list, but rather receives it in the 
  
getOutput/invokeAction calls, but still able to publish a 
  schema for those 
properties? Were there any 
  interesting other approaches and pros and cons? 

  
Regarding properties, did you envision that any schema would 
  be legal, or 
did you envision a model where the scheme 
  is constrained in some way (e.g., 
name value pairs, 
  ...)? 

  
You chose to have a semi-dynamic model for adaptation points, 
  so they are 
not specified as part of the WSDL (makes 
  sense, since they might change 
with versions of the 
  implementation), but are the same for all instances 
(i.e., not on a per-instance basis). Did you have discussions around 
  cases 
where the WSXL service is itself highly 
  customizable or personalized (based 
on user / 
  configuration / sequence of pages / properties) so that the page 
  
layout changes significantly, and how to address that within 
  the framework? 

  
Eilon 
      
  -----Original Message----- 
      From: Rich Thompson [mailto:] 
      Sent: Friday, April 12, 2002 12:17 
  PM 
      To: 
   
      Subject: [wsrp] WSXL paper update 
  

  
      Here is the update that will be 
  appearing soon on developerWorks: 

  
      (See attached file: 
  WSXL_Position_Paper.zip)