I agree that calling out the explicit conflict is a good idea. I guess my question is whether we get any value from an additional normative statement?
-Eric.
David Booz wrote:
OFEF79AEF7.59E7D032-ON85257631.0068138E-85257631.00685AE8@us.ibm.com" type="cite">Maybe, it depends on how the reader might interpret the meaning or purpose of the various intents and config options. We had an interesting debate on the meaning of delivery-mode. I still see value in being explicit about conflicts that we know about. If there are others we should get those addressed as well.
Dave Booz
STSM, BPM and SCA Architecture
Co-Chair OASIS SCA-Policy TC and SCA-J TC
"Distributed objects first, then world hunger"
Poughkeepsie, NY (845)-435-6093 or 8-295-6093
e-mail:booz@us.ibm.com
Eric Johnson ---09/14/2009 02:32:42 PM---Hi Dave If that's the case, isn't the other normative statement equally redundant?
From:
Eric Johnson <eric@tibco.com>
To:
David Booz/Poughkeepsie/IBM@IBMUS
Cc:
sca-bindings@lists.oasis-open.org
Date:
09/14/2009 02:32 PM
Subject:
Re: [sca-bindings] Proposed resolution to BINDINGS-85
Hi Dave
If that's the case, isn't the other normative statement equally redundant?
More below.
David Booz wrote:I guess that's proof enough that I really, really, really, haven't read it!
Eric,
There's this from the policy FW spec:
If the configured instance of a binding is in conflict with the intents and policy sets selected for that instance, the SCA runtime MUST raise an error. [POL30001].
It's the very first normative statement in the spec.
Agreed.
I don't think we need your second normative statement below.
-Eric.
Dave Booz
STSM, BPM and SCA Architecture
Co-Chair OASIS SCA-Policy TC and SCA-J TC
"Distributed objects first, then world hunger"
Poughkeepsie, NY (845)-435-6093 or 8-295-6093
e-mail:booz@us.ibm.com
Eric Johnson ---09/14/2009 01:38:20 PM---Hi Simon, I like the proposal, but I'm wondering whether the text at the end is singling out the pa
From:
Eric Johnson <eric@tibco.com>
To:
Simon Holdsworth <simon_holdsworth@uk.ibm.com>
Cc:
sca-bindings@lists.oasis-open.org
Date:
09/14/2009 01:38 PM
Subject:
Re: [sca-bindings] Proposed resolution to BINDINGS-85
Hi Simon,
I like the proposal, but I'm wondering whether the text at the end is singling out the particular policy intent "atLeastOnce", when, in fact, a more general statement applies - for example, transaction intents, or vendor defined intents that might conflict with a JMS configuration.
That is, something more like this:
This specification does not define a fixed relationship between any intents or combination thereof, and a particular configuration of a JMS binding. For example, this specification does not define any relationship between reliability intents and the persistence of JMS messages. Deployers/assemblers can configure NON_PERSISTENT for @deliveryMode in order to provide higher performance with a decreased quality of service. A binding.jms element configured in this way might not be able to satisfy the "atLeastOnce" policy intent. The SCA runtime MUST raise an error at deployment time if it is unable to support the combination of @deliveryMode=NON_PERSISTENT and the "atLeastOnce" intent [BJM5000X]. More generally, the SCA runtime must raise an error if it is unable to support the intents on a binding in combination with the specific configuration of the JMS binding [BJM5000X].
(I'm not entirely happy with the above, because we would then have two normative statements, where one is just a generalization of the other, but I thought I'd get across my notion for discussion purposes.)
Once again, my unfamiliarity with policy spec strikes again. Are both of these normative statements actually redundant with normative requirements that come from the policy specification? If so, shouldn't we just reference that part of the policy spec?
-Eric
Simon Holdsworth wrote:--------------------------------------------------------------------- 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
Folks, in the interests of moving to a conclusion on this here's my proposed resolution. I think there is also an issue with respect to the lack of defaults defined in the JMS binding for deliveryMode, priority and timeToLive attributes, I believe they should be defined as having the same defaults as on the JMS API (persistent, 4 and unlimited respectively) so I will open a new issue for that.
Proposal:
Keep the deliveryMode attribute as is.
Replace the final paragraph in section 5 (as updated in the resolution to issue 48) to read:
This specification does not define a fixed relationship between the reliability intents and the persistence of JMS messages. Deployers/assemblers can configure NON_PERSISTENT for @deliveryMode in order to provide higher performance with a decreased quality of service. A binding.jms element configured in this way might not be able to satisfy the "atLeastOnce" policy intent. The SCA runtime MUST raise an error at deployment time if it is unable to support the combination of @deliveryMode=NON_PERSISTENT and the "atLeastOnce" intent [BJM5000X].
Regards, Simon
Simon Holdsworth
STSM, SCA Bindings Architect; Master Inventor; OASIS SCA Bindings TC Chair
MP 211, IBM UK Labs, Hursley Park, Winchester SO21 2JN, UK
Tel +44-1962-815059 (Internal 245059) Fax +44-1962-816898
Internet - Simon_Holdsworth@uk.ibm.com
From: ashok malhotra <ashok.malhotra@oracle.com> To: Eric Johnson <eric@tibco.com> Cc: David Booz <booz@us.ibm.com>, sca-bindings@lists.oasis-open.org Date: 11/09/2009 22:12 Subject: Re: [sca-bindings] Further thoughts on issue BINDINGS-85
One of the cornerstones of the intent model is that intents can be
satisfied either intrinsically by a binding
or by use of config params on the binding. I see Eric's message and some
of the earlier discussion saying that,
no, intents cannot be satisfied by config params. If this is true, we
need to change the model.
If this is not the case, can we have a few examples of how intents can
be satisfied by configuring a binding.
All the best, Ashok
Eric Johnson wrote:
> I also like Simon's text, but for a different reason.
>
> I just checked with one of our JMS experts, and he pointed out to me
> that PERSISTENT and NON_PERSISTENT have little to do with the policy
> notions of atMostOnce or atLeastOnce. Instead, what matters is the
> particular use of the JMS APIs. Are transactions being used? What
> kind of acknowledgment mode is in play? Does the particular JMS
> vendor provide any extensions that might be used to satisfy the policies?
>
> So I concur - policy settings shouldn't map to a specific delivery
> mode setting, and the proposed text about flagging a conflict between
> delivery mode and policy seems appropriate to me.
>
> -Eric.
>
> David Booz wrote:
>>
>> Simon,
>>
>> I don't like the idea of expanding the meaning of any of the
>> reliability intents beyond their current numerical meaning. It's
>> important (though not required) for intents to have a consistent
>> meaning across bindings to enable binding replace-ability within SCA
>> as much as possible. Therefore, given your concern that
>> NON_PERSISTENT might encompass an implied non-functional requirement
>> for a high speed transport, then I would tend to favor the latest
>> solution that you just proposed.
>>
>> Dave Booz
>> STSM, BPM and SCA Architecture
>> Co-Chair OASIS SCA-Policy TC and SCA-J TC
>> "Distributed objects first, then world hunger"
>> Poughkeepsie, NY (845)-435-6093 or 8-295-6093
>> e-mail:booz@us.ibm.com
>>
>> Inactive hide details for Simon Holdsworth ---09/11/2009 06:05:18
>> AM---Ashok, Comments inline.Simon Holdsworth ---09/11/2009 06:05:18
>> AM---Ashok, Comments inline.
>>
>>
>> From:
>> Simon Holdsworth <simon_holdsworth@uk.ibm.com>
>>
>> To:
>> sca-bindings@lists.oasis-open.org
>>
>> Date:
>> 09/11/2009 06:05 AM
>>
>> Subject:
>> Re: [sca-bindings] Further thoughts on issue BINDINGS-85
>>
>> ------------------------------------------------------------------------
>>
>>
>>
>>
>> Ashok,
>>
>> Comments inline.
>>
>> ashok malhotra <ashok.malhotra@oracle.com> wrote on 10/09/2009 18:41:27:
>>
>> > Simon:
>> > Let me analyze this from the other side i.e. what the reliability
>> > intents map to in terms of the DIMS binding config params.
>> > The Policy Framework defines 4 reliability intents. Here is what,
>> in my
>> > understanding, they map to in
>> > terms of DIMS delivery mode:
>> >
>> > - atLeastOne: Persistent (this is more than what is requested but
>> that
>> > may be OK)
>> > - atMostOnce: Non-Persistent
>> > - exactlyOnce (atLeastOnce+atMostOnce): Persistent
>> > - ordered: No appropriate config param. Supported by the runtime.
>> > So, two questions:
>> > - Simon, is this what you suggested?
>>
>> Yes, that's what I was suggesting. The problem with this
>> relationship is that it is asymmetric - you can't say "atMostOnce
>> implies delivery mode is Non-Persistent" because if exactlyOnce is
>> required, it also requires atMostOnce, and in that case delivery mode
>> is Persistent.
>>
>> The problem for me is that while exactlyOnce satisfies the abstract
>> numerical requirement of atMostOnce, the cost of providing the
>> additional restriction of atLeastOnce doesn't satisfy the (in my
>> opinion expected) non-functional requirement of atMostOnce which is
>> provision of a high performance lightweight message interaction. I
>> think that would be the reason the intent would be selected by people
>> familiar with JMS, expecting to use it to achieve a NON_PERSISTENT
>> deliveryMode for their messages sent by the JMS binding.
>>
>> Another way of saying this is that I don't believe
>> deliveryMode=PERSISENT satisfies the requirements of
>> deliveryMode=NON_PERSISTENT so I don't believe we can say that the
>> JMS binding always satisfies atLeastOnce, which I think Anish was
>> questioning.
>>
>> My take on this issue is that if we can't come up with a clear
>> relationship between the intents and delivery modes that we can
>> explain in the JMS binding so that JMS-savvy people know what to
>> expect from their JMS binding, or if we retain the purely numerical
>> interpretation of the reliability intents, then we should retain the
>> current deliveryMode attribute and resolve the issue by weakening the
>> current statement of incompatibility along the lines:
>>
>> Deployers/assemblers can configure NON_PERSISTENT for @deliveryMode
>> in order to provide higher performance with a decreased quality of
>> service. A binding.jms element configured in this way might not be
>> able to satisfy the "atLeastOnce" policy intent. The SCA runtime MUST
>> raise an error at deployment time if it is unable to support the
>> combination of @deliveryMode=NON_PERSISTENT and the "atLeastOnce"
>> intent [BJM5000X].
>>
>> > - Others, does this make sense?
>> > All the best, Ashok
>> >
>> >
>> > Simon Holdsworth wrote:
>> > >
>> > > The JMS 1.1 specification has the following to say about the
>> > > deliveryMode attribute (Section 4.7, Message Delivery Mode):
>> > >
>> > > A JMS provider must deliver a NON_PERSISTENT message /at-most-once.
>> > > /This means that it may lose the message, but it must not deliver it
>> > > twice.
>> > > A JMS provider must deliver a PERSISTENT message
>> /once-and-only-once/.
>> > > This means a JMS provider failure must not cause it to be lost,
>> and it
>> > > must not deliver it twice.
>> > >
>> > > So it seems quite reasonable to map the SCA atMostOnce intent to JMS
>> > > delivery mode of NON_PERSISTENT, and exactlyOnce to PERSISTENT,
>> > > although exactlyOnce is a profile intent that combines atMostOnce
>> and
>> > > atLeastOnce, which would imply to me that atLeastOnce maps to a JMS
>> > > delivery mode of PERSISTENT. Although this does make life quite
>> > > difficult, because bindings that require exactlyOnce do also require
>> > > atLeastOnce.
>> > >
>> > > The only question I have left with regards to removing the
>> > > deliveryMode attribute as the resolution to this issue is whether we
>> > > should mandate in the JMS binding spec a specific mapping of these
>> > > intents to deliveryMode values, or remain silent and leave that
>> > > interpretation up to the SCA runtime.
>> > >
>> > > If we were to mandate the mapping, then the resolution to the issue
>> > > would be to remove the deliveryMode attribute, and replace the
>> > > following paragraph in section 5:
>> > >
>> > > Deployers/assemblers can configure NON_PERSISTENT for
>> @JMSDeliveryMode
>> > > in order to provide higher performance with a decreased quality of
>> > > service. A binding.jms element configured in this way cannot satisfy
>> > > the "atLeastOnce" policy intent. The SCA runtime MUST raise an error
>> > > for this invalid combination at deployment time.
>> > >
>> > > with:
>> > >
>> > > The JMS delivery mode used to send messages from a JMS binding
>> > > instance which requires the atMostOnce intent and not the
>> atLeastOnce
>> > > intent MUST be NON_PERSISTENT [BJM5000X]
>> > > The JMS delivery mode used to send messages from a JMS binding
>> > > instance which requires the atLeastOnce intent MUST be PERSISTENT
>> > > [BJM5000Y]
>> > >
>> > > Given the deliveryMode default is PERSISTENT, we could also say:
>> > >
>> > > The JMS delivery mode used to send messages from a JMS binding
>> > > instance which does not require either of these intents MUST be
>> > > PERSISTENT [BJM5000Z]
>> > >
>> > > In fact these could all be collapsed into a single statement:
>> > >
>> > > The JMS delivery mode used to send messages from a JMS binding
>> > > instance MUST be NON_PERSISTENT if it requires the atMostOnce intent
>> > > and not the atLeastOnce intent, and PERSISTENT otherwise [BJM5000X]
>> > >
>> > > Comments?
>> > >
>> > > Regards, Simon
>> > >
>> > > Simon Holdsworth
>> > > STSM, SCA Bindings Architect; Master Inventor; OASIS SCA Bindings
>> TC Chair
>> > > MP 211, IBM UK Labs, Hursley Park, Winchester SO21 2JN, UK
>> > > Tel +44-1962-815059 (Internal 245059) Fax +44-1962-816898
>> > > Internet - Simon_Holdsworth@uk.ibm.com
>> > >
>> > >
>> > >
>> ------------------------------------------------------------------------
>> > >
>> > > /
>> > > /
>> > >
>> > > /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
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