sca-assembly message
[Date Prev]
| [Thread Prev]
| [Thread Next]
| [Date Next]
--
[Date Index]
| [Thread Index]
| [List Home]
Subject: Re: [sca-assembly] [Issue 253]: (1.2) Must a global domain channel bedeployed before it can be used?
- From: Mike Edwards <mike_edwards@uk.ibm.com>
- To: "OASIS Assembly" <sca-assembly@lists.oasis-open.org>
- Date: Mon, 7 Feb 2011 11:39:20 +0000
Eric,
My view is that global channels - indeed
any channels - are more than a name - they have configuration associated
with them. A system which does
not require them to be declared makes it difficult to provide required
configuration.
Yours, Mike
|
|
Dr Mike Edwards
| Mail Point 146, Hursley
Park
|
|
STSM
| Winchester, Hants SO21
2JN
|
SCA & Services
Standards
| United Kingdom
|
Co-Chair OASIS SCA
Assembly TC
|
|
|
IBM Software Group
|
|
|
Phone:
| +44-1962 818014
|
|
|
Mobile:
| +44-7802-467431 (274097)
|
|
|
e-mail:
| mike_edwards@uk.ibm.com
|
|
|
|
|
From:
| Eric Johnson <eric@tibco.com>
|
To:
| Anish Karmarkar <Anish.Karmarkar@oracle.com>
|
Cc:
| sca-assembly@lists.oasis-open.org
|
Date:
| 04/02/2011 17:14
|
Subject:
| Re: [sca-assembly] [Issue 253]: (1.2)
Must a global domain channel be deployed before it can be used? |
On 2/4/11 1:37 AM, Anish Karmarkar wrote:
> I don't see this being different than say requiring that a variable
be
> declared before it is used.
<eej>
Which might be a perfect analogy.
If the only point of a global channel is to establish a name, then
there's actually minimal value to declaring it before it is used. Many
dynamic languages work this way - Python & Ruby. In the case of global
domain channels, for many use cases, filters and bindings don't make
sense, so the channel just becomes a name. At which point, declaration
before use looks like ceremony over substance.
</eej>
>
> -Anish
> --
>
> On 2/1/2011 10:11 AM, Danny van der Rijn wrote:
>> An interesting argument for tight coupling...
>>
>> On 2/1/2011 6:19 AM, Anish Karmarkar wrote:
>>> I think this is a fine issue to raise, but I don't quite support
the
>>> auto-creation proposal. The only global channel that is
>>> 'auto-deployed' or always exists is the default channel.
>>>
>>> I would want the runtime to tell me if I referenced a channel
that has
>>> not been deployed (unless it is the default channel, which
is the
>>> exception). If I want a producer and consumer (especially
if they are
>>> in different composites) to communicate over a common channel,
I would
>>> want the system to catch typos. For example, if the producer
is
>>> connected to the channel "//omg" and the consumer
is connected to
>>> "//zomg", they would be deployed fine but my application
would not
>>> work correctly.
>>>
>>> -Anish
>>> --
>>>
>>> On 1/31/2011 10:19 AM, Eric Johnson wrote:
>>>> Hi Peter,
>>>>
>>>> On 1/31/11 10:02 AM, Peter Niblett wrote:
>>>>> Eric
>>>>>
>>>>> You said..
>>>>>
>>>>> Neither of the above indicate whether or not the global
domain
>>>>> channel
>>>>> can be used before it is referenced.
>>>>
>>>> Ah yes, the joys of a muddled brain on Monday morning.
You're
>>>> correct -
>>>> the question is whether or not the global domain channel
can be used
>>>> before it is *created* via a contribution.
>>>>
>>>> Thanks for catching my circularity.
>>>>
>>>> -Eric.
>>>>>
>>>>> I'm not sure how you can "use" a channel
without referencing it (I
>>>>> assume "reference" means "wire to/from"),
but I think the question
>>>>> you
>>>>> are asking is the one in the title - "can you
reference a channel
>>>>> that
>>>>> hasn't been defined to the SCA assembly?". I
think this is one place
>>>>> where the current spec is clear.. you can't reference
a domain
>>>>> channel
>>>>> that hasn't been defined.
>>>>>
>>>>> So it looks as though your issue is to say that we
should change the
>>>>> spec to say that it permits (in fact requires) autocreation
of domain
>>>>> channels. Presumably these channels would have to
be created with
>>>>> default attributes (though I know you think they shouldn't
have
>>>>> attributes at all).
>>>>>
>>>>> Regards
>>>>>
>>>>> Peter Niblett
>>>>> IBM Senior Technical Staff Member
>>>>> Member of the IBM Academy of Technology
>>>>> +44 1962 815055
>>>>> +44 7825 657662 (mobile)
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> From: Eric Johnson<eric@tibco.com>
>>>>> To: OASIS SCA Assembly<sca-assembly@lists.oasis-open.org>
>>>>> Date: 31/01/2011 17:19
>>>>> Subject: [sca-assembly] NEW ISSUE: (1.2) Must a global
domain channel
>>>>> be deployed before it can be used?
>>>>> ------------------------------------------------------------------------
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> Title: Must a global domain channel be deployed before
it can be
>>>>> used?
>>>>>
>>>>> Target: Assembly 1.2 WD 03
>>>>>
>>>>> Description:
>>>>>
>>>>> Via the "@target" and "@source"
attributes defined on a consumer&
>>>>> producer, the assembler can reference global domain
channels.
>>>>>
>>>>> In section 5.8, the presumed to be normative text
reads "SCA runtimes
>>>>> MUST support the use of domain channels [ASM????]."
That is followed
>>>>> by:
>>>>>
>>>>> "To create a Domain Channel, deploy a composite
containing a channel
>>>>> directly to the SCA Domain (i.e., do not use that
composite as the
>>>>> implementation of some component in the Domain)."
>>>>>
>>>>> Neither of the above indicate whether or not the global
domain
>>>>> channel
>>>>> can be used before it is referenced.
>>>>>
>>>>> Proposal:
>>>>>
>>>>> General theme: do not require the global domain channel
to exist
>>>>> before
>>>>> it can be used.
>>>>>
>>>>> Specific text (needs refinement?):
>>>>>
>>>>> In section 5.8, Paragraph #2, append:
>>>>>
>>>>> When contributing artifacts to a domain that contain
references to
>>>>> global domain channels that have not been created,
the SCA runtime
>>>>> MUST
>>>>> automatically create said global domain channels,
and cannot reject
>>>>> such
>>>>> contributions [ASM????].
>>>>>
>>>>>
>>>>>
>>>>> ---------------------------------------------------------------------
>>>>> 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/
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>
>>> ---------------------------------------------------------------------
>>> 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
>>
>
> ---------------------------------------------------------------------
> 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
---------------------------------------------------------------------
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
[Date Prev]
| [Thread Prev]
| [Thread Next]
| [Date Next]
--
[Date Index]
| [Thread Index]
| [List Home]