I've just posted to the OASIS documents repository a proposal for
I posted in PDF and Word format:
These documents are *not* in anything close to final form:
However, before I spent many hours trying to get everything perfect, I
figured I should at least know whether the intent is even close to
acceptable to the TC.
- OpenOffice did a number of things to slightly mangle the word
- We need new pictures to show the new channel promotion notion.
I've included my notion of what it would look like below, in the hopes
that it will help, although I should add that so far within TIBCO, I've
gotten the some disagreement about the proposed artwork.
- I haven't vetted the schema changes.
- Obviously this is still a fork of the current spec, based off of
the copy that Anish started from.
P.S. My current conception of a channel might look like - see diamond
at the bottom edge of the component.
On 04/09/2010 01:19 AM, Mike Edwards wrote:
Forwarding to the main sca-assembly
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
----- Forwarded by
Edwards/UK/IBM on 09/04/2010 09:18 -----
Title: Promotion of SCA consumers and producers undermines composibility
In the assembly 1.2 WD 01, consumers and producers are identified as
of the "component type" of a component, whereas "channels"
are limited in scope to the boundaries of a composite. This is
to the rest of SCA, where the indication of the communication between
surfaces in the component type, currently as a service or reference.
When needed, services or references can establish concrete bindings,
otherwise communication needs are exposed at the boundary of a
In the case of producers, consumers, and channels, not only can
be applied, but also "targets", which then either hide endpoints
within a composite, or expose them globally as part of the "global
This makes composition of applications using eventing more difficult.
Further, although producers and consumers can refer to the same target,
this is an awkward way for these two constructs to establish that they
intend to operate on the same "destination". When building
a composite the composite developer may wish for one component to
for a channel, and a different component to publish on the same
and then promote the combination of producer and consumer. If the
developer only promotes the consumer, or only promotes the publisher,
would be misleading to the composites using that component. Perhaps
it is even an error.
Here, then, are two problems:
- "target" channel references are a weak way to
couple the use of the same destination.
- target channel references can be to a domain
thus undermining composability - either by collisions in the naming of
target channels, or by forcing special knowledge of which channels are
Instead of promoting consumers and producers, promote channels. Move
the filter and eventType information on consumers and producers into
Unless stated otherwise above:
IBM United Kingdom Limited - Registered in England and Wales with
Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6