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Subject: RE: [wsbpel-spec-edit] Friendly amendments to issue 89 proposal


no, same text same section :-)  i just suggested a minor nit-level correction and a possible move to a different section when we reorg the whole spec.
 
 
 


From: Alex Yiu [mailto:alex.yiu@oracle.com]
Sent: Wednesday, October 27, 2004 3:45 PM
To: Liu, Kevin
Cc: Satish Thatte; ygoland@bea.com; bpel spec; Alex Yiu
Subject: Re: [wsbpel-spec-edit] Friendly amendments to issue 89 proposal


Ok.  I got a bit confused after all these emails. :-)  Just a clarification.
It will be basically the same text from Yaron but just ending up in a different section?
Right?


Regards,
Alex Yiu


Liu, Kevin wrote:
Great. I will apply the changes tonight when I get CVS access at home. 

Best Regards,
Kevin
 

-----Original Message-----
From: Satish Thatte [mailto:satisht@microsoft.com] 
Sent: Wednesday, Oct 27, 2004 02:41 PM
To: Liu, Kevin; ygoland@bea.com; Alex Yiu
Cc: bpel spec
Subject: RE: [wsbpel-spec-edit] Friendly amendments to issue 89 proposal


I am fine with Yaron's text, except for the nit that queryLanguage is
used in WSDL for defining property aliases not properties :-)

OK to put in 6.2 for now.  Later on we probably need to reorganize to
merge this type of stuff with section 3 but that is not something to
take on right now. 

Satish
 

-----Original Message-----
From: Liu, Kevin [mailto:kevin.liu@sap.com] 
Sent: Wednesday, October 27, 2004 12:03 PM
To: Satish Thatte; ygoland@bea.com; Alex Yiu
Cc: bpel spec
Subject: RE: [wsbpel-spec-edit] Friendly amendments to issue 89 proposal

OK, We need to move on with this. 

First, let's see if we can agree on the location. Do we all agree that
section 6.2 is the right place given the change is applicable to both
abstract and executable process (note section 14 is only for executable
process)?

As for the text, personally I like Yaron's version better since it fits
into the context of section 6.2 and re-uses the "processor" term instead
of introduce another one. It also clarifies the case for WSDL. 

Satish, do you agree that we can move on with Yaron's text as the base?


Best Regards,
Kevin
 

-----Original Message-----
From: Satish Thatte [mailto:satisht@microsoft.com]
Sent: Tuesday, Oct 26, 2004 03:18 PM
To: ygoland@bea.com; Alex Yiu
Cc: Liu, Kevin; bpel spec
Subject: RE: [wsbpel-spec-edit] Friendly amendments to issue 89 proposal


The executable/abstract distinction is not relevant here.  The only
point we are trying to make is that you MUST *statically* determine if
you can FULLY understand the process definition before you do anything
with it.  In other words, the various language attributes have
"mustUnderstand" status.

-----Original Message-----
From: Yaron Y. Goland [mailto:ygoland@bea.com] 
Sent: Tuesday, October 26, 2004 3:12 PM
To: Alex Yiu
Cc: Liu, Kevin; bpel spec; Satish Thatte
Subject: Re: [wsbpel-spec-edit] Friendly amendments to issue 89 proposal

When I wrote 89 the status of abstract processes was unclear so I stuck 
to just addressing executable processes. Officially speaking nothing has
changed in the status of abstract processes but I believe that the 
direction we have been heading is to define some level of syntax 
conformance requirement for abstract processes (e.g. it will be possible
to perform non-trivial static analysis of an abstract process). The 
consequence of this is that it makes sense to apply 89 to both abstract 
and executable processes and it therefore makes sense to move the text 
to a section that applies to both types of processes, section 6.2 seems 
like a good candidate.

I also agree with Alex's concerns. I think the proposed language may 
have unintentional implications that could complicate things.

I therefore propose that we edit your proposed language to read:

The value of the queryLanguage and expressionLanguage attributes on the 
process XML element are global defaults and can be overridden on 
specific activities like assign using the mechanisms defined later in 
this specification. In addition the queryLanguage attribute is also 
available for use in defining BPEL properties in WSDL. BPEL processors
MUST:
  * statically determine which languages are referenced by queryLanguage
or expressionLanguage attributes either in the BPEL process definition 
itself or in any BPEL property definitions in associated WSDLs and
  * if any referenced language is unsupported by the BPEL processor then
the processor MUST NOT process the submitted BPEL process definition.

	What do y'all think?

		Yaron

Alex Yiu wrote:
  
Hi Kevin,

Thanks for the update.

The wordings of "the processor MUST stop processing the process" seems
to imply that the BPEL implementation will behave like an interpreter,
when the implementation is an executation engine. It looks like that
    
the
  
processor stops processing only after it discovers the
    
expression/query
  
language support problem.

Does it imply that a BPEL execution engine implementation should not
    
do
  
static analysis?
Or, I am just reading too much into the intention of the sentence?

One way or the other, I think it would be better to put addtional
sentences to explicitly state that whether static analysis may/must be
performed to detect this error condition.

And, if an execution engine implementation is ever allowed to discover
this problem on the fly in the middle of the process execution, then a
runtime fault may be needed.

Instead of have one vague statements that covers all kinds of BPEL
processors. We may want to have some terms introduced: e.g. BPEL
execution processor and BPEL analysis processor (which do static
analysis and other analysis without executing the BPEL process). Then,
our description against different kinds of processors can be more
    
precise.
  
I think these 2 terms are needed also, when we want to give a context
for Issue 9.


Thanks!


Regards,
Alex Yiu


Liu, Kevin wrote:

 >Hi Yaron and all,
 >
 >There was a brief discussion on 89 in the editors' call last week.
    
Since Yaron 
  
had already been swamped with many issues, the group felt obligated to
    
take some 
  
burden from his shoulder, and somehow I ended up with an AI to come up
    
with new 
  
text to address some concerns Satish brought up.

 >
 >Here is the strawman proposal I would like to you to bring up for
    
your 
  
consideration. Though the changes might appear violent (at least more
    
than I was 
  
thinking), I believe the principal idea is the same as the initial
    
proposal.
  
 >
 >To be honest, I don't have a strong feeling on this issue and am
    
totally open 
  
for any suggestions.  Please just send me (or to the editor's group
    
directly) 
  
your wording if you have a preference.

 >
 >
 >The issue:
 >===============
 >Handling Unrecognized Query/Expression Languages - What is a BPEL
    
engine to do 
  
if the query/expression language identifier given in 
queryLanguage/expressionLanguage attributes are unrecognized?

 >
 >Initial Proposal:
 >================
 >From: "Yaron Y. Goland" <ygoland@bea.com>
 >To: wsbpeltc <wsbpel@lists.oasis-open.org>
 >Date: Wed, 15 Sep 2004 18:16:31 -0700
 >
 >Add the following language to the end of section 14.1:
 >
 >If the value of a queryLanguage or expressionLanguage attribute in a
 >BPEL executable process identifies a language that the execution
    
engine
  
 >does not support then the execution engine MUST NOT execute the BPEL
 >process.
 >
 >Concerns from Satish:
 >====================
 >1. The wording sounds like that it only applicable to "execution
    
engine". 
  
Actually the logic should be applicable to any thing that deals with a
    
BPEL process
  
 >
 >2. Need to clarify that this is not only concerned with the two
    
attributes in 
  
the root element, but to all levels
 >
 >My strawman amendments:
 >==============================
 >The issue called out "BPEL engine", but if I understand Satish's
    
concern 
  
correctly, he thinks the proposal should work for all BPEL processors
    
and to all 
  
levels of BPEL elements. How about the following?

 >
 >1. The location
 >The proposal is to change section 14.1. In the latest draft, section
    
14.1 only 
  
deals with executable extensions for expressions.


http://www.oasis-open.org/apps/org/workgroup/wsbpel/download.php/9094/w
    
sbpel-specification-draft-Sept-08-2004.html#s.Extensions.top
  
 >
 >Since the issue address both query language and expression language,
    
and is 
  
general for both abstract and executable processes, I feel section 6.2
    
is a 
  
better place to address this general issue.

 >
 >2. The text
 >
 >Change the following section in 6.2 to add a paragraph (proposed
    
changes 
  
marked with [[...]])
 >
 >The top-level attributes are as follows:
 >
 >*         queryLanguage. This attribute specifies the default XML
    
query 
  
language used for selection of nodes in assignment, property
    
definition, and 
  
other uses. The default value for this attribute is XPath 1.0,
    
represented by 
  
the URI of the XPath 1.0 specification: 
http://www.w3.org/TR/1999/REC-xpath-19991116.

 >
 >*         expressionLanguage. This attribute specifies the
    
expression language 
  
used in the process. The default for this attribute is XPath 1.0,
    
represented by 
  
the URI of the XPath 1.0 specification: 
http://www.w3.org/TR/1999/REC-xpath-19991116.

 >
 >*         suppressJoinFailure. This attribute determines whether the
    

  
joinFailure fault will be suppressed for all activities in the
    
process. The 
  
effect of the attribute at the process level can be overridden by an
    
activity 
  
using a different value for the attribute. The default for this
    
attribute is 
  
"no" at the process level.  When this attribute is not specified for
    
an 
  
activity, it inherits its value from its closest enclosing activity or
    
from the 
  
process if no enclosing activity specifies this attribute.

 >
 >*         abstractProcess. This attribute specifies whether the
    
process being 
  
defined is abstract (rather than executable). The default for this
    
attribute is 
  
"no".

 >
 >[[
 >The value of the querLanguage attribute and the value of the 
expressionLanguage attribute at the process level can be overridden by
    
an 
  
activity using a different value for that attribute. If the specified
    
query or 
  
expression language is not supported by a processor which has to deal
    
with the 
  
relevant query or expression, the processor MUST stop processing the
    
process.
  
 >]]
 >
 >...
 >
 ></new>
 >
 >Please note the term "processor" is already used in section 6.4, so
    
I am not 
  
inventing a new term for this issue, though a separate issue might be
    
opened for 
  
defining what a "processor" is.

 >
 >Thoughts?
 >
 >Best Regards,
 >Kevin
 > 
 >


    



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