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[wot-discovery] minutes - 10 August 2020

From: Kazuyuki Ashimura <ashimura@w3.org>
Date: Tue, 18 Aug 2020 21:33:25 +0900
Message-ID: <87o8n8xhey.wl-ashimura@w3.org>
To: public-wot-wg@w3.org
available at:

also as text below.

Thanks a lot for taking the minutes, Andrea!



      [1] http://www.w3.org/

                               - DRAFT -

                             WoT Discovery

10 Aug 2020


      [2] https://www.w3.org/WoT/IG/wiki/WG_WoT_Discovery_WebConf#10_August_2020


          Kaz_Ashimura, Michael_McCool, Andrea_Cimmino,
          Christian_Kurze, Cristiano_Aguzzi,
          Farshid_Tavakolizadeh, David_Ezell, Kunihiko_Toumura,
          Tomoaki_Mizushima, Michael_Koster



          andrea_cimmino, kaz


     * [3]Topics
         1. [4]Guests
         2. [5]Previous minutes
         3. [6]MongoDB
         4. [7]PR 38
         5. [8]PR 47
     * [9]Summary of Action Items
     * [10]Summary of Resolutions

   <kaz> scribenick: andrea_cimmino


   christian from MongoDB is present

   meeting starts with christian presenting himself

   <kaz> (Christian has read the W3C Patent Policy and understands
   the RF commitment)

Previous minutes

   McCool: minutes from last meeting are reviewed

   <inserted> [11]August-3

     [11] https://www.w3.org/2020/08/03-wot-discovery-minutes.html

   McCool: PR for anonymous TD was created, as stated in the
   ... remind McCool to create issue for the spec issues/43
   ... remind McCool during MongoDB discussion to create an
   idempotent issue
   ... minutes proposed for publication with no further comments

   minutes reviewed and publish, changing topic now to MongoDB


   McCool: Does MongoDB supports JSON-LD? and XPath?

   Christian: it supports Json-LD
   ... regarding XPath, MongoDB supports a similar query language

   McCool: it would be good to have the spec of such language
   ... the place to collaborate is to have a second implementation
   based on MongoDB

   Farshid: current implementation is not based on MongoDB
   ... instead the implementation uses LevelDB

   Christian: how does LevelDB is used?

   Farshid: the key is the ID and the value the TD

   McCool: the TDD have an API to register, and then someone can
   filter the TD. TDs have an id field, which is optional,
   therefore sometimes the ids must have a created on the fly id
   ... there could be other meta-data, also not included.
   Therefore we rely on a wrapper object to support such
   ... ids can be updated, they are not immutable
   ... the general idea is that authorized devices can receive
   notifications, so basically, when the TD changes de id it has
   to be deleted first, re-created, and then notify those devices
   ... when created on the fly, maybe, ids should not be changed
   if TD is updated
   ... bottom line, the draft needs to include how to deal with
   this stuff
   ... implementation time should be until January 2022
   ... candidate recommendation July 2021 (CR)
   ... final for December 2021
   ... ideally, July 2021 we should have two implementations that
   satisfy the requirements

   <kaz> (Implementation report plan by CR transition;
   Implementation Report with concrete results by PR transition)

   McCool: implementations do not need to be Open Source, but they
   must pass the tests

   farshid: our implementation is based on the requirements of a
   project, from which we got involved in this initiative
   ... there are things outside the specifications, like how the
   data is stored, and instead, the specification details the APIs
   ... in this way someone can implement internally the spec with
   the desired technologies, but still implement the same spec

   McCool describes how the current draft is structured

   McCool: the draft does not specifies the internal functioning
   ... one of the issues are the type of search supported: XPath,
   Json Path, and SPARQL
   ... we will need a SPARQL-based implementation if SPARQL is
   ... Xpath and Json path are still under discussion

   <kaz> (Kaz's note: basic expectation is all the features
   including optional features should have more than one
   implementation; but there should be multiple implementations
   given SPARQL is also a W3C Recommendation.)

   McCool: clarification, the project of Farshid was originally
   LinkSmart, from which other projects were derived and this
   component enhanced
   ... having an open SPARQL can be dangerous, therefore, it will
   be used for advanced implementation
   ... the baseline is Json Path and XPath
   ... in general, regarding the architecture, privacy is a
   ... since distributing data can be used to infer information
   and also track people
   ... in the discovery there will be two steps: introducing first
   (only informative), and then the exploration mechanisms
   ... even if christian does not implement a version, your
   contribution and experience will be very valuable
   ... for instance, in the idempotent issue

   Christian: the problem here is how to identify anonymous TD
   ... a hash could be calculated, but the order of the keys is
   ... the full td should be used for the hash, so two TD are
   identical only if their whole content is the same

   McCool: here the thing is that the same device could create
   different TDs that are the same, exactly the same content

   Farshid: some UC may include this beahviour
   ... for these cases maybe a short life span may help
   ... two devices are identical, and publishing the same TD, and
   only their payloads are different
   ... these, once registered, get a unique ID. But this ID is
   unknown during registration. Everything should work fine

   McCool: maybe we should register a special TD, get the ID, and
   then register the right TD with the ID
   ... let's further discuss this
   ... let's create an issue and discuss (assigned to farshid)

   <FarshidT> Issue to discuss how to handle anonymous TD and
   avoid duplicates:

     [12] https://github.com/w3c/wot-discovery/issues/48

PR 38

   <kaz> [13]PR 38

     [13] https://github.com/w3c/wot-discovery/pull/38

   discussion about last befrancis issue, farshid already replied

   Farshid: the comments are outside the scope of directory
   ... like, having a TDD that automatically creates TDs from

   McCool: maybe we could approach this creating micro-services
   that perform different tasks
   ... nevertheless, McCool agrees with Farshid

   McCool replies in the PR

   McCool proposes merging the PR, since no objections are done,
   PR is merged

PR 47

   scribenick: kaz

   <kaz> [14]PR 47

     [14] https://github.com/w3c/wot-discovery/pull/47

   <kaz> [15]diff

     [15] https://pr-preview.s3.amazonaws.com/w3c/wot-discovery/47/5ff4fe9...AndreaCimminoArriaga:0f50db5.html

   <kaz> [16]changes

     [16] https://github.com/w3c/wot-discovery/pull/47/files

   McCool: (captures several issues as comments)

   [17]McCool's comments

     [17] https://github.com/w3c/wot-discovery/pull/47#issuecomment-671409816

   <Zakim> kaz, you wanted to suggest we use <h2> with <section>
   for ReSpec. Please see also:

     [18] https://github.com/w3c/respec/wiki/section

   <kaz> (<h5> surrounded by <section> and </section> is OK,


Summary of Action Items

Summary of Resolutions

   [End of minutes]

    Minutes manually created (not a transcript), formatted by
    David Booth's [19]scribe.perl version ([20]CVS log)
    $Date: 2020/08/17 14:19:26 $

     [19] http://dev.w3.org/cvsweb/~checkout~/2002/scribe/scribedoc.htm
     [20] http://dev.w3.org/cvsweb/2002/scribe/
Received on Tuesday, 18 August 2020 12:33:30 UTC

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