I still see a requirement for scoping the
exchange of events so that it stays encapsulated within a composite. It
has hard to develop and test such a composite if there's a risk that its
internal components can get bombarded with events from who knows where
once it is deployed. That was my understanding for why we had private
channels in the first place.
There are other ways in which you can
reference a genuine external JMS topic
1. Reference a global channel bound
to the JMS topic (global channels seem a much better fit for something
that is external to the whole assembly)
2. Bind the producer or consumer directly
to the JMS topic
3. Promote the producer or consumer
to the composite level, and bind that to the JMS topic.
Of course I could get the functionality
I want from private channels in another way if I were allowed to wire producers
directly to consumers.
Peter Niblett
IBM Senior Technical Staff Member
Member of the IBM Academy of Technology
+44 1962 815055
+44 7825 657662 (mobile)
From:
Anish Karmarkar <>
To:
OASIS Assembly <>
Date:
01/02/2011 15:02
Subject:
[sca-assembly]
Private or local channels
During last week's call Peter and I had a little bit
of back on forth in
the chat regarding private/local channels. I would like to start a
discussion on it on the ML before I file an issue (or not, depending on
the outcome of the discussion).
Peter has pointed out that line 2815 of our spec says:
"Channels within a composite used as an implementation are private
to
the components within that composite. These private channels can only be
the targets for producers existing within the same composite as the
channel. Private channels can only be sources for consumers existing
withing the same composite as the channel. An SCA runtime MAY support
the use of private channels "
Peter's interpretation of this is that composite channels are not
visible to components outside the composite *and* to anyone outside of
the SCA-world. I have a different interpretation of this. I don't think
our spec should talk about what things outside of SCA do or don't do. We
should allow for enough freedom wrt the technology use to implement the
channels. It could be an in-memory channel that is true invisible to
anyone outside the process or a JMS topic, which would have visibility
outside of SCA. We currently allow bindings on a composite channel; that
to me indicates that we intended to allow such variability. If folks
agree with my interpretation, I think we should change the wordings to
replace 'private' with 'local', so as not the give an incorrect impression.
Comments?
-Anish
--
---------------------------------------------------------------------
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
