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Subject: RE: [sca-assembly-comment] Some more comments

I think that answers my question, but raises two more comments:
[12a] this spec should really be part of the main Assembly model ! (definitely in a next version)   I notice that quite a few repeats from the main model were needed anyway to handle the extension, that would not be needed in a merger.
[12b] Is it really necessary to introduce new "Consumer" and "Producer" constructs ? couldn't these be just a particular  profiling of "Service" ? (and maybe also of "Reference" in case the producer function pushes the events). I believe that the main SCA assembly model should still say "something"  about the pub-sub / event connection models. Even if new constructs (producer / consumer / channel) are needed to treat the full extent of these connection modes, end-users may still want to use the "basics" for  simple cases of event-based communication. Some best practice in appendix on how they can use (or profile) Service / Reference, would do the job. 

From: Mike Edwards [mailto:mike_edwards@uk.ibm.com]
Sent: Wednesday, June 24, 2009 1:01 AM
To: Jacques R. Durand
Cc: sca-assembly-comment@lists.oasis-open.org
Subject: Re: [sca-assembly-comment] Some more comments


Regarding Comment 12:

You may like to take a look at the OSOA SCA Event Processing specification which has been submitted to the OASIS Assembly TC
and which forms part of the input to the resolution of Assembly Issue-80:


While not in any way official as far as OASIS is concerned, it does show an SCA model for a more decoupled model for interaction between components using
event sending and pub/sub techniques.

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: "Jacques R. Durand" <JDurand@us.fujitsu.com>
To: <sca-assembly-comment@lists.oasis-open.org>
Date: 23/06/2009 22:48
Subject: [sca-assembly-comment] Some more comments

[Comment 11b] :  The chicken or the egg... (or the COmposite vs. the Component)
(rewording of my previous comment #11)
It is unclear why the Composite is always the outermost construct, as the markup
indicates. It seems that the mark-up does not allow to expose the Component
directly to users, yet the component has the same interfacing constructs
(Services / Properties / References) as the Composite.
Yet apparently SCA implementations will often directly expose Components (which may
or may not be implemented as composites), e.g. in the C++ model.
Couldn't the mark-up reflect this abstraction and make Component top-level (beside or even instead of Composite?)
NOTE: this comment could be modified along my previous comment #9: if some form of "container"
is needed for all kinds of SCA constructs (Services, Rferences, Components, Composites...)
that should probably be something new, different from "Composite".
[Comment 12]: Best practices for most typical architecture patterns?
The control model suggested by Composites, is of Components invoking each others via
references and wires. It is unclear how that plays with more decoupled architecture patterns
between components:
- publish-subscribe async communication between Components
(should a queue manager be itself modeled as a component?)
- event listeners.
[Comment 13]: I don't think there is a clear definition of what an "SCA runtime" is.

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