RE: [sca-assembly] [NEW ISSUE] Wiring from a reference with no binding to a service with a binding

["Peshev, Peter" <peter.peshev@sap.com>]

Hi,

 

when looking at the description, it seems that this is closely connected (maybe even classified as duplicate) to the already raised ASSEMBLY-1  (http://www.osoa.org/jira/browse/ASSEMBLY-1),  which has the following description :

 

It is not clear whether presence of binding.sca can always be assumed for internal wires, specifically when standard bindings are associated with either end of that internal wire

 

 

Although the suggested proposal in ASSEMBLY-1 (adding binding.sca implicitly to each service/reference  and thus satisfying the wiring algorithm requirements for the case "reference with no binding to a service with a binding")  seems to be different than the currently suggested proposal (changing the algorithm).

 

 

 

Best Regards

Peter

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From: Mike Edwards [mailto:mike_edwards@uk.ibm.com]
Sent: Tuesday, 27. November 2007 17:43
To: OASIS Assembly
Subject: [sca-assembly] [NEW ISSUE] Wiring from a reference with no binding to a service with a binding

<This issue is transferred from 
the SCA Policy TC where it was dubbed POLICY-34> 

RAISER  Michael Rowley (original) 

TARGET:  SCA Assembly 
Specification 

DESCRIPTION: 

The algorithm in the policy spec says that 
it is _not_ possible to wire from a reference that does not declare a binding 
(i.e. uses binding.sca) to a service that declares one or more bindings. 
However, I think this should be possible. 

It is an unreasonable requirement to say that a service with a binding 
can only be the target of a reference that has that same binding. The default 
binding (binding.sca) should be treated as the "I don't care" binding, and 
should work with any binding available within the domain. Or, more precisely, 
any binding that can satisfy the required intents. 

Section 4.8.1 of  the Policy frmework spec 
states: 

The wiring compatibility 
algorithm below determines the compatibility of a wire by a pairwise choice of a 
binding instance and the corresponding policySets on each side of the 
wire. 

This should be changed to the 
following: 

If either side of a wire 
does not specify a binding (or explicitly specifies binding.sca) the wire is 
considered to be valid for the purposes of policy processing. If both sides of 
the wire use binding.sca then the policies will be determined by the union of 
the required intents of both sides (policy sets aren't used with binding.sca). 
Otherwise, the bindings and policies used for the wire will be determined by 
adding the intents that are required by the binding.sca end of the wire to the 
other end of the wire and then following the section 4.10 algorithm in the Polcy 
Framework. 

If neither side of the 
wire uses binding.sca, then the wiring compatibilty algorithm below is used for 
determining compatibility. Note that there may be many binding instances present 
at each side of the wire. This algorithm determines the compatibility of a wire 
by a pairwise choice of a binding instance and the corresponding policySets on 
each side of the wire. 

PROPOSAL: 

The following 
should be added to the Wires section of the Assembly specification: 

If either end of a wire does not specify a 
binding (or explicitly specifies binding.sca) the wire is regarded as valid. 
 In other words, binding.sca is regarded as being compatible with 
any other type of binding.  Where other 
types of binding are applied to each end of a wire, compatibility of the two 
bindings is determined by the specifications for the two bindings 
involved, allied to the intent and policies 
attached at each end.  In general, a wire which has two different binding 
types at each end (non binding.sca) is likely not to be valid. 

If both ends of the wire use binding.sca 
then the policies will be determined by the union of the required intents of 
both ends (policy sets aren't used with binding.sca). 
Otherwise, where one end of the wire uses binding.sca, 
the bindings and policies used for the wire will be determined by adding the 
intents that are required by the binding.sca end of the wire to the other end of 
the wire and then following the algorithm defined in the Policy Framework 
specification section 4.10. 

If 
neither end of the wire uses binding.sca, then the wiring compatibilty algorithm 
described in section 4.10 of the Policy Framework specification is used for 
determining compatibility. Note that there may be many binding instances present 
at each side of the wire. This algorithm determines the compatibility of a wire 
by a pairwise choice of a binding instance and the corresponding policySets on 
each side of the wire. 


Yours, 
 Mike.

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  
Email: 
 mike_edwards@uk.ibm.com

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