Issue 30 - Is the policy (specified in intentMap) from all of multiplequalified intents in effect? - PROPOSAL

[David Booz <booz@us.ibm.com>]

Here's the issue (http://www.osoa.org/jira/browse/POLICY-30) text taken
from JIRA
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Consider a policySet that provides intent A with default A.X in an
intentMap. The SCDL contains:

<binding.myBinding requires="A.Y A.Z" policySets="PolicySetThatProvidesA"/>

Clearly we override A.X but with A.Y or A.Z, or is it an error? The spec
does not say. The decision comes down to

a) additive (A.Y and A.Z)
b) mutually exclusive (A.Y or A.Z)

We don't have a mechanism to express either (a) or (b).

Once we have the mechanism laid down, then the rule gets clear:

a) For additive intents, the default intent is replaced by all the
specified intents and all of the selected policies
get applied

b) For exclusive intents, it is an error for A.Y and A.Z to be specified
together.


PROPOSAL:

Issue 39 (http://www.osoa.org/jira/browse/POLICY-39) was resolved by adding
mutual exclusivity to an intent definition.
Here is the jist of the issue 39 resolution:

<spec fromBulletList = "true">
- @mutuallyExclusive attribute (optional) with a default of “false”.  If
this attribute is present and has a value of “true” is indicates that the
qualified intents defined for this intent are mutually exclusive.
<spec>

With the resolution of Issue-39, the resolution to Issue 30 does become
more clear as stated in the issue 30 text.

However, I believe that more text needs to be added to the spec. Therefore
I would propose to change the spec text shown above to the following (as
the resolution of Issue 30):

- @mutuallyExclusive attribute (optional) with a default of “false” which
means that the qualified intents defined for this intent are additive.  If
this attribute is present and has a value of “true” then the qualified
intents defined for this intent are mutually exclusive.



Dave Booz
STSM, BPM and SCA Architecture
Co-Chair OASIS SCA-Policy TC
"Distributed objects first, then world hunger"
Poughkeepsie, NY (845)-435-6093  or  8-295-6093
e-mail:booz@us.ibm.com