Scribe
- Andrew Berezovskyi (KTH)
Attendees
- Andrew Berezovskyi (KTH)
- Jim Amsden (IBM)
- Martin Sarabura (PTC)
- Nick Crossley (IBM)
- David Honey (IBM)
Resolutions
- Propose that the spec say a query result MUST be an LDPC - and that the subsequent requirements fit in with that (for example, by using appropriate LDPC properties to use rdfs:member as a membership predicate
by default)
Actions
Chat transcript from room: oslc
[14:06] Martin Sarabura: Minutes from previous meeting: https://wiki.oasis-open.org/oslc-core/Meetings/Telecon2018.07.12
[14:08] Andrew Berezovskyi (KTH): Scribe: Andrew
[14:08] Andrew Berezovskyi (KTH): Minutes approved
[14:10] Andrew Berezovskyi (KTH): Jim: Nick's question about the CM domain spec being standardised before Core should be discussed.
[14:11] Andrew Berezovskyi (KTH): CM mostly introduces optional things
[14:12] Andrew Berezovskyi (KTH): no objections
[14:12] Andrew Berezovskyi (KTH): Jim: statements of use anything specific on that?
[14:12] Andrew Berezovskyi (KTH): Martin: v2 compliant servers being compliant with v3 can qualify as statements of use
[14:13] Andrew Berezovskyi (KTH): most of the optional features do not need the ref impl
[14:15] Andrew Berezovskyi (KTH): Jim: we had these conversations with the steering comm, mostly regarding LDP related items not being exercised; StC was OK with that
[14:15] David Honey (Persistent/IBM): https://tools.oasis-open.org/version-control/browse/wsvn/oslc-core/trunk/specs/oslc-query.html
[14:15] Andrew Berezovskyi (KTH): last week we finished section 7, starting with section 8
[14:20] Andrew Berezovskyi (KTH): Q. Result Containers needed to be backwards compat, even though the spec was unclear. If there is no resource shape on the ResCont, the rdfs:member is the membership
predicate. If there is a shape, then a new membership predicate can be declared with oslc:isMemberProperty true. LDP was is to declare a separate container with the membership resource.
[14:21] Andrew Berezovskyi (KTH): JIm: so these are three methods for the memb. predicate, this is an overkill
[14:22] Andrew Berezovskyi (KTH): Jim: why care about LDPC adoption in case of the Query (only)?
[14:23] Andrew Berezovskyi (KTH): RQM is one of the tools using a custom predicate
[14:24] Andrew Berezovskyi (KTH): ^(NIck)
[14:26] Andrew Berezovskyi (KTH): one option is that we make LDPC method a must, the oslc predicate can be a MAY; Martin thinks it would be good to have a "clean" implementation example. Jim: in reality most clients & servers would have to implement all options.
[14:27] Andrew Berezovskyi (KTH): Jim: we can adopt LDP as the memb pred specification mechanism, then express the default rdfs:member and oslc predicate as membership predicate and an equiv predicate membership declaration method respectively
[14:29] Andrew Berezovskyi (KTH): David: if nothing is provided, rdfs:member MUST be used. If a shape is given, a given predicate MUST be used. If we make LDPC a must, all v2.0 implementation will not be compliant with v3.0.
[14:30] Andrew Berezovskyi (KTH): Nick: that would not be the end of the world. we want compat for clients, not necessarily for the servers!
[14:31] Andrew Berezovskyi (KTH): David: the 2.0 spec was vague on some statements and just by clarifying them in 3.0, many servers may be incompatible with the 2.0 clients
[14:34] Andrew Berezovskyi (KTH): David: LDPC still can be a MUST and the clients will still be able to consume the results via shapes
[14:34] Andrew Berezovskyi (KTH): David: this will make the section simpler
[14:34] Andrew Berezovskyi (KTH): Jim: I don't see the much demand for LDPC in this context.
[14:35] Andrew Berezovskyi (KTH): David: I don't think SHOULD will be of any help to promote the use of LDPCs.
[14:37] Andrew Berezovskyi (KTH): Jim: MUST has risk of forcing some constraints that have no value prop
[14:39] Andrew Berezovskyi (KTH): OPC-UA
[14:41] Andrew Berezovskyi (KTH): strong points: strong specs of profiles and certification
[14:42] Andrew Berezovskyi (KTH): downside: 1200 pages+ in the ISO standards
[14:42] Andrew Berezovskyi (KTH): Jim: OSLC has a different philosophy
[14:43] David Honey (Persistent/IBM): https://www.w3.org/TR/ldp/#ldpbc
[14:44] Andrew Berezovskyi (KTH): Jim: is the LDPC MUST and no explicit membership predicate are incompatible
[14:44] Andrew Berezovskyi (KTH): Nick: again, that will make existing 2.0 servers non-3.0 compliant
[14:45] Andrew Berezovskyi (KTH): Jim: it will inhibit integration
[14:45] Andrew Berezovskyi (KTH): David: it would be just a few more triples
[14:45] Andrew Berezovskyi (KTH): Jim: products will be slow adopting this
[14:47] Andrew Berezovskyi (KTH): Andrew: I believe we should consider OSLC version header, as HTTP, TLS and others do
[14:50] Andrew Berezovskyi (KTH): Nick: versioning would allow gradual improvement. Jim: we need to encourage compatibility and have clients discover new capabilities.
[14:50] Andrew Berezovskyi (KTH): Andrew: what if we do two different capabilities and support discovery
[14:51] Andrew Berezovskyi (KTH): Nick: but that would place a lot of burden on the impl: new predicate, new endpoint etc. + old clients won't discover
[14:52] Andrew Berezovskyi (KTH): Andrew: agree, just trying to accomod Jim's discovery requirement
[14:54] Andrew Berezovskyi (KTH): Jim: what if we had the LDPC MUST, clients would check for LDPC and if none exists, you check for the oslc membership, finally, go for rdfs. Nick: RQM, DNG apps differ in the predicates; clients are already complicated because
the spec was imprecise.
[14:56] Andrew Berezovskyi (KTH): David: would require verbose triples in the response. Jim: nothing esp. bad with this, there are some cases.
[14:57] Andrew Berezovskyi (KTH): Jim: is MUST/SHOULD on LDPC consistent here with the rest of the document?
[14:57] Andrew Berezovskyi (KTH): Jim: LQE uses rdf:member
[14:57] Andrew Berezovskyi (KTH): Nick: LQE is not a reference here
[14:58] Andrew Berezovskyi (KTH): David: the Q is whether LDPC requirement should be upgraded to a MUST or remain a SHOULD.
[14:59] Andrew Berezovskyi (KTH): David proposes a vote whether whether the LDPC requirement should be upgraded to a MUST.
[15:01] Nick Crossley (IBM): Propose that the spec say a query result MUST be an LDPC - and that the subsequent requirements fit in with that (for example, by using appropriate LDPC properties to use rdfs:member as a membership predicate by default)
[15:02] David Honey (Persistent/IBM): +1
[15:02] Jim Amsden: 0
[15:02] Andrew Berezovskyi (KTH): 0
[15:02] David Honey (Persistent/IBM): Seconded
[15:02] Nick Crossley (IBM): Nick: +1
[15:02] Martin Sarabura: +1
[15:03] Andrew Berezovskyi (KTH): Motion carried
[15:04] Andrew Berezovskyi (KTH): Jim: now we have the framework to approach similar issues in TRS
[15:04] Andrew Berezovskyi (KTH): the meeting is adjourned
Dr. Martin Sarabura
Technical Fellow, Office of Research & Architecture
+1 (519) 502-4819
msarabura@ptc.com
ptc.comâ