RE: [wsbpel] Issue - 72 - ( was RE: [wsbpel] Issue 47 and WS-I BP 1.0)

From
"Gurniss, Oeter"
Date
2003-10-02T17:03:01+00:00
ID
Thread
RE: [wsbpel] Issue - 72 - ( was RE: [wsbpel] Issue 47 and WS-I BP 1.0)
Title: Message

How on 
earth is that to be enforced ? Are we considering an abstract case, a bpel 
engine, a process script or a particular running instance ?  Does a BPEL 
script that has one BP-compliant partnerlink become illegal if one day it's 
bound (via appropriate WSDL) to MQ ?  Must a BPEL engine fault an attempt 
to use it to map between a non-BP 1.0 client and a differently non-BP 1.0 
service, mangling between the messages to make them acceptable to 
each.

 

Peter

 

 -----Original 
Message-----
From: Ugo Corda [mailto:] 

Sent: 02 October 2003 17:54
To: Furniss, Peter; BPEL 
OASIS
Subject: RE: [wsbpel] Issue - 72 - ( was RE: [wsbpel] Issue 47 
and WS-I BP 1.0)

  
Please keep in 
  mind that saying that BPEL should offer a BP-compliant service 
  only means that at least one WSDL port offered by the BPEL process has to be 
  BPEL-compliant. The BPEL process could provide additional non-compliant ports 
  and still be considered BP-compliant.

  
 

  
Ugo

  
    
-----Original Message-----
From: Furniss, Peter 
    [mailto:]
Sent: Thursday, October 02, 
    2003 2:30 AM
To: BPEL OASIS
Subject: [wsbpel] Issue - 72 
    - ( was RE: [wsbpel] Issue 47 and WS-I BP 1.0)

    

    
I 
    would strongly support Postel's law in general, but I'm not sure it applies 
    so easily to BPEL.

    
 

    
The detailed content and format of particular 
    messages sent from (be conservative) or received by (be liberal) a BPEL 
    process are obviously subject to Postel's law, but that's a matter for the 
    binding and the involved protocols, and their profiles.

    
 

    
The equivalent for BPEL would first appear to be, 
    as Ron says,  be liberal in the web services you use, conservative in 
    the ones you offer.  However, the use/offer polarity is determined by 
    the WSDL MEP's in use. In the case of asynchronous 
    relationships, where there are paired port types one-way 
    operations, there isn't any obvious distinction as to which side 
    is doing the specifying and which is obediently following 
    it. Even for request/response patterns, it isn't invariably the case 
    that the server has freedom to choose (and thus to obey BP 1.0) and the 
    client has to follow the dictates of the server (whether it obeys BP 1.0 or 
    not), which is the basis of Postel's law.

    
 

    
For BPEL, or indeed for business protocols in 
    general, which side has the initiative is probably determined by other 
    features (which side has more economic clout or more deployed implementation 
    or less intelligent developers or got there first). Postel's law applies as 
    something like "be generous in what you demand of others, providing there is 
    unambiguity; be precise in how you follow the demands of others, even if it 
    doesn't seem entirely reasonable".

    
 

    
 

    
Peter

    
      

      
-----Original Message-----
From: Ron Ten-Hove 
      [mailto:] 
Sent: 01 October 2003 
      21:48
To: Eckenfels. Bernd
Cc: BPEL 
      OASIS
Subject: Re: [wsbpel] Issue 47 and WS-I BP 
      1.0

    Perhaps we should invoke 
      Postel's law, with respect to basic profile conformance. To promote 
      interoperability, we should be as permissive as possible when dealing with 
      (other) web services, but as conformant as possible when creating our own 
      (BPEL engine provided) web services.

    I realize 
      this falls mostly on implementations to worry about, but the basic profile 
      does contain a lot of restrictions and clarifications for the "abstract" 
      service model that may be of interest.. The ban on operation overloading 
      might be slightly simplifying, for example. 

    
      Anyway, a quick scan of the BP didn't reveal anything scary to me. It 
      seems to me that WS-I BP 1.0 compliance will be an implementation worry, 
      but as a technology that will rely on interoperation of our SOAP 
      infrastructure, we ought to encourage (but not mandate) BP 
      compliance.

-Ron

Eckenfels. Bernd wrote:

      
        
        

        
Hello Ugo,

        
 

        
I think it is not good to speak about violation if an 
        implementation is able to communicate with an larger number of 
        systems.

        
 

        
Perhaps we should chnage this: "conformant BPEL engines must be 
        able to provide and consume Web Services according to BP 1.0a 
        specification. Engine should not provide Web Services with HTTP SOAP 
        binding other than BP1.0 conformant.

        
 

        
Actually I see the point of requiring BP1.0 support as a 
        conformance rule, but I dont see a point of restricting engines to that, 
        even if it applies.

        
 

        
Mit freundlichen Grüßen
Bernd 
        Eckenfels
Chief 
        Architect
--
SEEBURGER AG - Edisonstr.1 , D-75015 Bretten, 
        Germany
Fax: +49 (0)7252 96-2400 - Phone: +49 (0)7252 
        96-1256
mailto: - http://www.seeburger.de 

        
          
-----Original Message-----
From: Ugo Corda [mailto:]
Sent: 
          Wednesday, October 01, 2003 8:28 PM
To: Satish Thatte; 
          Prasad Yendluri; Eckenfels. Bernd
Cc: BPEL 
          OASIS
Subject: RE: [wsbpel] Issue 47 and WS-I BP 
          1.0

          
Right, RPC 
          literal would be fine, but RPC encoded would be in 
          violation.

          
            
-----Original Message-----
From: Satish Thatte [mailto:]
Sent: 
            Wednesday, October 01, 2003 11:23 AM
To: Ugo Corda; Prasad 
            Yendluri; Eckenfels. Bernd
Cc: BPEL 
            OASIS
Subject: RE: [wsbpel] Issue 47 and WS-I BP 
            1.0

            

            
So for 
            instance the RPC encoded services bound to SOAP/HTTP would be in the 
            “in scope but in violation” category?

            

            

            

            
            

            
From: Ugo 
            Corda [mailto:] 
            
Sent: Wednesday, 
            October 01, 2003 11:18 AM
To: Satish Thatte; Prasad Yendluri; 
            Eckenfels. Bernd
Cc: BPEL OASIS
Subject: RE: [wsbpel] Issue 47 
            and WS-I BP 1.0

            

            

            
Let 
            me clarify point 4 (sorry, I mislabeled it as 3) in relation to 
            point 1.

            

            

            

            
I 
            think we should distinguish services that are not compliant with BP 
            1.0 from those that are simply out of scope for BP 
            1.0.

            

            

            

            
If I 
            have a Web service that is not bound to SOAP/HTTP, then I would say 
            it is out of scope for BP 1.0, so it's OK for BPEL to interact with 
            it.

            

            

            

            
My 
            point 4 is about services that are within the scope of BP 1.0 and 
            still do not comply with its requirements.

            

            

            

            
Ugo

            
              
-----Original 
              Message-----
From: Satish Thatte [mailto:]
Sent: Wednesday, October 01, 
              2003 11:09 
              AM
To: 
              Ugo Corda; Prasad Yendluri
Cc: BPEL OASIS
Subject: RE: [wsbpel] Issue 
              47 and WS-I BP 1.0

              
I doubt 
              that we can mandate BPEL to be used with BP 1.0 compliant services 
              only especially given the answer to 1 assuming it is correct, and 
              given that there are many services today that are not compliant 
              (e.g., RPC encoded ones).

              

              

              

              
              

              
From: 
              Ugo Corda [mailto:] 
              
Sent: Wednesday, 
              October 01, 2003 10:55 AM
To: Satish Thatte; Prasad 
              Yendluri
Cc: BPEL 
              OASIS
Subject: 
              RE: [wsbpel] Issue 47 and WS-I BP 1.0

              

              

              
I 
              see a few separate issues/questions connected to the 
              relationship of BP 1.0 and BPEL.

              

              

              

              
1- Would 
              BP 1.0 be restricting BPEL to the point that some of BPEL's 
              functionality would not be available?

              

              

              

              
I 
              cannot think of any such restriction off the top of my 
              head.

              

              

              

              
2- 
              Would the fact that BP 1.0 only addresses the SOAP/HTTP binding 
              imply that also BPEL should be limited to that type of 
              binding?

              

              

              

              
I 
              don't think that anybody would imply that.

              

              

              

              
3- 
              Should a BPEL process be offered as a Web service that is BP 1.0 
              compliant?

              

              

              

              
My 
              answer would be yes.

              

              

              

              
3- 
              Would it be fair to limit BPEL use to interacting with BP 1.0 
              compliant Web services only?

              

              

              

              
My 
              personal answer would be yes. But I am a member of WS-I, and I 
              understand other people might have different 
              answers.

              

              

              

              

              

              
Ugo

              
                
-----Original 
                Message-----
From: Satish Thatte [mailto:]
Sent: Wednesday, October 01, 
                2003 10:39 
                AM
To: Prasad 
                Yendluri
Cc: 
                BPEL OASIS
Subject: RE: [wsbpel] Issue 
                47 and WS-I BP 1.0

                
For the 
                benefit of the non-expert could post a salient example 
                please?  Specifically, a BPEL usage pattern that would not 
                work if BP 1.0 is followed but would work if any WSDL 1.1 
                portType is allowed.  In other words, is BP 1.0 a 
                restriction on the WSDL artifacts we use or potentially on BPEL 
                itself?

                

                

                

                
                

                
From: 
                Prasad Yendluri [mailto:] 
                
Sent: 
                Wednesday, October 01, 2003 10:11 AM
To: Satish Thatte
Cc: BPEL OASIS
Subject: Re: [wsbpel] Issue 
                47 and WS-I BP 1.0

                

                
The sections 5.5 and 5.6 in the basic 
                profile (http://www.ws-i.org/Profiles/Basic/2003-08/BasicProfile-1.0a.htm) 
                are devoted to binding aspects but, several major sections 
                including section 4, other sections of 5 address abstract 
                aspects of WSDL, which is a pretty large portion. All those are 
                applicable BPEL IMO.

Prasad

Satish Thatte 
                wrote:

                
Most of the BP 1.0 
                directives are binding related.  BP also forbids outbound 
                operations which BPEL does not use.  Can someone identify a 
                directive in BP 1.0 that actually affects 
                BPEL?

                

                
Satish