OASIS Mailing List ArchivesView the OASIS mailing list archive below
or browse/search using MarkMail.

 


Help: OASIS Mailing Lists Help | MarkMail Help

sca-assembly message

[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]


Subject: RE: [sca-assembly] [ISSUE 132] Rebuttal: Against the use of portability andfunctions as reasons for requiring one of the existing 4 languages



Don,

I think that the central question at issue here is what it means to claim conformance to the SCA Assembly Model spec.

Currently, the requirement essentially covers two things:

a) that the SCA runtime concerned passes the Conformance test suite

b) that an SCA specification exists for the implementation language that is used in the Conformance test suite

At the moment, because we're doing the standardization work at OASIS, both of these requirements are tied to OASIS:

- the test suite is required to be the one that is available from the OASIS website, freely available to all
- the SCA specification for the implementation type is one that is available from OASIS, again freely available to all


I think that the debate that is going on is about modifying these requirements.

I believe that these requirements don't restrict the ability to support any implementation type or implementation language with SCA.
Clearly, it is possible to extend the conformance suite to embrace new implementation types and it is also possible to bring
forward specifications for new implementation types in SCA to OASIS for standardization.  That, in essence, is the approach
embodied in the current conformance statements in the Assembly spec.

I think that the debate is around whether this approach is too onerous and whether it should be relaxed in some ways so as to make it
easier and more attractive for anyone to build an SCA runtime for some new implementation type and then claim conformance for
that runtime.


So far, I believe that it is agreed that passing the conformance test suite is required in order to claim conformance.  The question is
how the test suite can be adapted for a new language. There is also question of the availability of the adapted test suite for anyone to
obtain and run.  If everything is done at OASIS, this is guaranteed.  If it is done elsewhere, how can it be guaranteed?


The issue of the need for some form of SCA specification for a new implementation type has been debated less, although in my
opinion, it does need debate and a clear answer.  First: is it still required to have an "SCA specification document" for some new
implementation type, independent of the venue for the creation and publication of such a document?  Secondly, if there is such
a document, is it required that it is available freely to all? Thirdly, if there is such a document, what requirements are there on its
contents?  I note that we have answers for all of these for SCA implementation type specifications developed at OASIS.  If such
documents are created in some other way, how do we ensure the right content and availability?



Yours,  Mike.

Strategist - Emerging Technologies, SCA & SDO.
Co Chair OASIS SCA Assembly TC.
IBM Hursley Park, Mail Point 146, Winchester, SO21 2JN, Great Britain.
Phone & FAX: +44-1962-818014    Mobile: +44-7802-467431  
Email:  mike_edwards@uk.ibm.com



From: "Ferguson, Donald F" <Donald.Ferguson@ca.com>
To: Mike Edwards/UK/IBM@IBMGB, "OASIS Assembly" <sca-assembly@lists.oasis-open.org>, <sca-assembly-comment@lists.oasis-open.org>
Date: 24/06/2009 11:42
Subject: RE: [sca-assembly] [ISSUE 132] Rebuttal: Against the use of portability and functions as reasons for requiring one of the existing 4 languages





I will reexamine the material. Does your respond mean that you are willing to remove the requirements on supporting certain languages? I have been having a little trouble with the mailing lists and may have missed your comments.
 
Thanks.
 
Dr. Donald F. Ferguson
Distinguished Engineer
Corporate Senior Vice President
Chief Architect Products and Technology
donald.ferguson@ca.com
donff2@aol.com
www.donald-ferguson.net/blog
 
From: Mike Edwards [mailto:mike_edwards@uk.ibm.com]
Sent:
Wednesday, June 24, 2009 6:27 AM
To:
Ferguson, Donald F; OASIS Assembly; sca-assembly-comment@lists.oasis-open.org
Subject:
RE: [sca-assembly] [ISSUE 132] Rebuttal: Against the use of portability and functions as reasons for requiring one of the existing 4 languages

 

Don,


I agree with you that we should define a conformance test for the SCA Assembly Model spec.


Have you had a chance to look at the test suite materials for SCA Assembly, which can be found here:


http://www.oasis-open.org/apps/org/workgroup/sca-assembly-testing/download.php/32963/sca-assembly-1.1-test-assertions-cd01.pdf
http://www.oasis-open.org/apps/org/workgroup/sca-assembly-testing/download.php/32961/sca-assembly-1.1-testcases-cd01.pdf
http://www.oasis-open.org/apps/org/workgroup/sca-assembly-testing/download.php/32967/sca-assembly-1.1-testcases-cd01.zip

I'm interested in your views as to the suitability of this test suite for testing conformance to the SCA Assembly spec.  If you can suggest

improvements, extensions or changes to any of the materials, that would be great.


As I said in my recent note in reply to Jim, one thing we don't say with regard to the current test suite materials is what can and what cannot

be changed in adapting the test materials to suite some new implementation type.  Suggestions for defining this are most welcome.



Yours,  Mike.

Strategist - Emerging Technologies, SCA & SDO.
Co Chair OASIS SCA Assembly TC.
IBM Hursley Park, Mail Point 146, Winchester, SO21 2JN, Great Britain.
Phone & FAX: +44-1962-818014    Mobile: +44-7802-467431  
Email:  mike_edwards@uk.ibm.com

From: "Ferguson, Donald F" <Donald.Ferguson@ca.com>
To: "Jim Marino" <jim.marino@gmail.com>, "OASIS Assembly" <sca-assembly@lists.oasis-open.org>, <sca-assembly-comment@lists.oasis-open.org>
Date: 23/06/2009 18:40
Subject: RE: [sca-assembly] [ISSUE 132] Rebuttal: Against the use of portability and functions as reasons for requiring one of the existing 4 languages

 







I do not see any reason to believe that we cannot define a conformance test for SCA Assembly. If we are able to do so, we would not need to require support for the core languages. I assert that 1) We should not assume that we cannot define a compliance test until we have tried. 2) An assembly spec that places requirements on internal implementation languages is flawed.

 
Finally, I was present in IBM when we started work on SCA. Language independence and encapsulation of implementation was an explicit objective.  The IBM architecture leadership would have vetoed any assembly spec with this requirement.

 
Dr. Donald F. Ferguson

Distinguished Engineer

Corporate Senior Vice President

Chief Architect Products and Technology

donald.ferguson@ca.com
donff2@aol.com
www.donald-ferguson.net/blog
 
From:
Jim Marino [
mailto:jim.marino@gmail.com]
Sent:
Tuesday, June 23, 2009 1:06 PM
To:
OASIS Assembly; sca-assembly-comment@lists.oasis-open.org
Subject:
Re: [sca-assembly] [ISSUE 132] Rebuttal: Against the use of portability and functions as reasons for requiring one of the existing 4 languages

 
Mike,
 
You did not addressed the points I was hoping you would. In fairness, I probably did not explain them clearly. Here's another try.
 
As background, I think we all agree on the value of strong, verifiable conformance and clear tests that can perform that task. No one is arguing that point. And no one is claiming vendors should be allowed to "invent" or otherwise modify portions of the conformance test suite with abandon :-). I'm sure we can safely assume everyone understands the virtues of conformance test suites and avoid rehashing them here.
 
Given that, my point is that a vendor should be able to claim conformance to the SCA Assembly specification without being required to be conformant with one of the official languages. One of the reasons given for not accepting Microsoft's request to change this requirement was, "
If there were no requirement to support one of the implementation types covered by the Open CSA Member Section, this would mean that end users could have no assurance that the SCA runtime concerned really provides the functions laid down by the SCA specifications"[1]. In a nutshell, I don't think the statement is accurate and I believe conformance tests that do not rely on a specific implementation type (other than composites) can be developed for Assembly. The purpose of my email was to outline how that could be accomplished.
 

I would not characterize this approach as more "open" since it still hold vendors (or open source projects) accountable in very defined and verifiable ways. It is perhaps more "modular" and arguably will promote portability, which is lacking with SCA.

 

What would I like to see? Basically, I would like a runtime to be able to claim conformance to the SCA Assembly Specification without having any requirements by way of a programming language. In other words, it should be possible for a runtime to pass the Assembly conformance suite without having to support any of the sanctioned programming language specifications. One proviso which could be attached to claim conformance is that a vendor (or open source project) would be required to make any artifacts required to run the tests (excluding the runtime) available under the same license terms as the OASIS tests. Given the current test suite requires vendor-specific code, this probably should be a requirement regardless of the present proposal.

 

I believe this approach would address the concerns raised by a number of parties during the public review. What issues do you see with this approach or is it acceptable in your view?

 

Jim

 
 

[1]
http://lists.oasis-open.org/archives/sca-assembly-comment/200905/msg00001.html.  
 
On Jun 23, 2009, at 4:03 PM, Mike Edwards wrote:



Jim,


Thanks for your comments.


First, I would like to point out that we have built the Assembly testcase suite along the lines that you

want to see.  It is built in a way that is language independent with all top level materials being

wholly composite based, and then with replaceable language-specific implementations at the

bottom.


Availability of the testcase suite in each of the OASIS supported language types is not a "convenience"

- it is a requirement.  We already have Java, and C, C++ and BPEL are well advanced.  Others will be

added as their specifications come forward to public review.


The second point about the testcase suite is that it is not just a matter for the SCA runtime implementers.

The idea is that the conformance testcase suite is available to all - anyone can take it and use it to
verify that some SCA runtime conforms to the specifications.  It is the open nature of the test suite that

is the biggest guarantee that SCA runtime vendors will take it seriously - no one can bend their way

around it without facing the possibility that users will catch them out.



The second question to address is what you really think it means to "conform" to the SCA specifications.


One important thing is that SCA is extensible and can accommodate the use of pretty well any implementation

technology and implementation language.  Any vendor can do this at any time.  So SCA is very much open,

as you desire.


However, claiming conformance is something else.  What does "claiming conformance" really mean?

To me, it means that the SCA runtime meets the requirements of the relevant SCA specifications.  

I am sure there is real value to end users in a claim of conformance - the end users can have  expectations

of a conforming system that it will work in a certain way - and that the end users knowledge of SCA will apply

to the conforming system.  It is clear that vendors also attach importance to claiming conformance too.


If conformance is to have any real meaning, I believe that this must mean adhering to the letter of the spec.

Our current approach to this is to require the passing of the test suite - as a minimum check.  There will always

be things that the test suite does not check - and for those, the wording of the conformance points in the spec

is the tool that people can use.


So, let us say that we want a more "open" approach to claiming conformance for a runtime that supports
one or more implementation languages not specified by any of the OASIS TCs.  How might we do this while

still retaining some meaning to the term "conformance"?  Some thoughts:


- Might we allow a claim of conformance for language "X" as long as there is a Test Suite for Assembly that

uses implementation language "X"?


- Might we allow a claim for conformance for language "X" as long as there is a specification for SCA component

implementations written in lnaguage "X"?  Without such a specification and in particular without a definition of

how the componentType is calculated for an implementation artifact written in language "X", how would it be

possible to know that the test suite was a valid test suite?


- Should it be required that the test suite and the specification for language "X" is available publicly with some

form of open terms?  I note that the current OASIS TC specs and test suite are available to anyone on open

terms - so that anyone can take them and run them.



What are your thoughts on this?


Yours,  Mike.

Strategist - Emerging Technologies, SCA & SDO.
Co Chair OASIS SCA Assembly TC.
IBM Hursley Park, Mail Point 146, Winchester, SO21 2JN, Great Britain.
Phone & FAX: +44-1962-818014    Mobile: +44-7802-467431  
Email:  
mike_edwards@uk.ibm.com

From: Jim Marino <jim.marino@gmail.com>
To: sca-assembly-comment@lists.oasis-open.org
Cc: OASIS Assembly <sca-assembly@lists.oasis-open.org>
Date: 10/06/2009 02:07
Subject: [sca-assembly] Rebuttal: Against the use of portability and functions as reasonsfor requiring one of the existing 4 languages


 


 






Hi,

I haven't had much time lately to participate in TC discussions on  
language conformance due to other commitments. However, I did have the  
opportunity to discuss the technical merits of this issue at length  
with people from Microsoft. I think I understand where they are coming  
from and believe there may be a way to accommodate Microsoft's  
concerns while also improving the SCA specifications.

Coupling conformance to the Assembly specification with one of the  
"official" TC languages places an unneeded and expensive burden on  
potential implementors that may not support one of those languages.  
This is particularly evident given the OASIS requirement for two  
independent conformant implementations. The original spirit of  
assembly was language independence and that can be maintained. It  
seems the main sticking point is with conformance testing: namely, how  
can language independent tests be created that verify assembly  
assertions?

As a proposal, I believe it is feasible to use composite  
implementations to create language independent verification tests. The  
tests would make extensive use of the implementation.composite type as  
well as service and reference promotions. The actual implementations  
would be contained in a separate contribution (or contributions) and  
made available to the using composite via the contribution import/
export mechanism. The verification tests would be run against the  
components using the composites and their promoted services, which  
would result in language independent conformance checks.

As a convenience, composites which used "official" language types such  
as implementation.java or implementation.bpel could be made available.  
However, it would also be possible for a vendor to supply their own  
composites that used a proprietary language.

Making assembly truly language independent would have two significant  
benefits, specifically portability and expanding SCA's relevance.  
Realistically, the best chance of achieving portability for SCA is at  
the assembly level. The further one goes "down" - e.g. into policy,  
component implementations, and actual application code - portability  
becomes problematic. For example, policy is not likely to be portable  
given the ability to use different policy languages. The Java  
specification also does not address many of the areas required to  
write portable applications such as database access and using managed  
threads. If Java EE is any indicator, achieving portability of  
application code is likely to require years of effort, and even then  
the results are likely to be incomplete. However, in my opinion,  
portability at the assembly level is a realistic goal and should be  
pursued by making it as language independent as possible.

Language independence would also expand the relevance of assembly to  
areas Java EE could never touch. Assembly can be used across a host of  
proprietary programming languages, essentially providing a portable  
blueprint of systems, regardless of the technologies they run on. In  
my opinion, this may prove to be the most important contribution SCA  
has to make.

Jim


---------------------------------------------------------------------
To unsubscribe from this mail list, you must leave the OASIS TC that
generates this mail.  Follow this link to all your TCs in OASIS at:

https://www.oasis-open.org/apps/org/workgroup/portal/my_workgroups.php



 



 

Unless stated otherwise above:
IBM United Kingdom Limited - Registered in England and Wales with number 741598.
Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 3AU





 





 

Unless stated otherwise above:
IBM United Kingdom Limited - Registered in England and Wales with number 741598.
Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 3AU











Unless stated otherwise above:
IBM United Kingdom Limited - Registered in England and Wales with number 741598.
Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 3AU








[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]