11:49:12 RRSAgent has joined #wot 11:49:12 logging to https://www.w3.org/2021/03/17-wot-irc 11:50:15 Meeting: WoT-IG/WG vF2F Meeting in March - Day 2 11:50:22 present+ Kaz_Ashimura 11:50:54 agenda: https://www.w3.org/WoT/IG/wiki/F2F_meeting,_March_2021#Wednesday_March_17 11:52:36 present+ Michael_McCool 11:52:54 McCool has joined #wot 12:00:14 present+ Philipp_Blum, Andrea_Cimmino, Chrstian_Glomb 12:00:48 present- Chrstian_Glomb 12:00:51 mjk has joined #wot 12:00:58 present+ Christian_Glomb 12:01:04 ktoumura has joined #wot 12:01:32 present+ Kunihiko_Toumura 12:01:46 could someone please post the webex coordinate for this teleconference? 12:03:11 present+ Ege_Korkan, Farshid_Tavakolizadeh 12:03:37 present+ Michael_Lagally 12:04:15 present+ Daniel_Peintner 12:04:31 present+ Sebastian_Kaebisch 12:04:42 thanks, kaz! 12:04:55 s/thanks, kaz!// 12:04:59 present+ Michael_Koster 12:05:10 zakim, who is on the call? 12:05:10 Present: Kaz_Ashimura, Michael_McCool, Philipp_Blum, Andrea_Cimmino, Christian_Glomb, Kunihiko_Toumura, Ege_Korkan, Farshid_Tavakolizadeh, Michael_Lagally, Daniel_Peintner, 12:05:12 Mizusima has joined #wot 12:05:14 ... Sebastian_Kaebisch, Michael_Koster 12:06:11 sebastian has joined #wot 12:06:13 Ege has joined #wot 12:06:13 topic: Scribe 12:06:18 dape has joined #wot 12:06:19 Sebastian for the 1st part 12:06:32 Daniel for the 2nd part 12:06:48 scribenick: sebstian 12:06:57 scribenick: sebastian 12:07:02 s/scribenick: sebstian// 12:07:11 present+ Ben_Francis 12:07:28 topic: Overview 12:07:41 FarshidT has joined #wot 12:07:54 -> https://www.w3.org/WoT/IG/wiki/F2F_meeting,_March_2021#Wednesday_March_17 agenda for today 12:08:40 present+ Cristiano_Aguzzi, Tomoaki_Mizushima 12:09:04 cris has joined #wot 12:09:32 MM gives an intro about Discovery 12:09:33 https://github.com/w3c/wot/tree/main/PRESENTATIONS/2021-03-online-f2f#wednesday-2021-03-17 12:09:51 mlagally has joined #wot 12:09:51 https://github.com/w3c/wot/blob/main/PRESENTATIONS/2021-03-online-f2f/2021-03-17-WoT-F2F-Opening-McCool.pdf 12:10:13 https://github.com/w3c/wot/blob/main/PRESENTATIONS/2021-03-online-f2f/2021-03-17-WoT-F2F-Discovery-Introduction-Mechanisms-Toumura.pdf 12:10:38 https://github.com/w3c/wot/blob/main/PRESENTATIONS/2021-03-online-f2f/2021-03-17-WoT-F2F-Discovery-Intro-McCool.pdf 12:10:50 s|https://github.com/w3c/wot/blob/main/PRESENTATIONS/2021-03-online-f2f/2021-03-17-WoT-F2F-Discovery-Introduction-Mechanisms-Toumura.pdf|| 12:11:04 rrsagent, make log public 12:11:09 rrsagent, draft minutes 12:11:09 I have made the request to generate https://www.w3.org/2021/03/17-wot-minutes.html kaz 12:11:17 citrullin has joined #wot 12:11:55 MM: the idea is to find devices in the field 12:12:16 present+ Soumya_Kanti_Datta 12:12:46 ... discovery goals have different capabilites such as local / global discovery 12:12:46 Chair: McCool/Sebastian 12:13:16 present+ Ryuichi_Matsukura 12:13:21 ... searching large repositories 12:13:32 ... p2p discovery 12:13:47 present+ Michael_Koster 12:14:01 present+ Sebastian_Kaebisch 12:14:02 ... another goal is to have privacy-preserving architecture 12:14:09 rrsagent, draft minutes 12:14:09 I have made the request to generate https://www.w3.org/2021/03/17-wot-minutes.html kaz 12:14:42 .... this includes lifecycle and user policy 12:15:01 ... we want also to be aligned with existing standards 12:15:38 ... currently we have a two-phase architecture 12:15:56 ... phase 1 is about introduction and phase 2 is about exploration 12:17:06 ... phase 1: first contact protocol which provides addresses of exploration service 12:17:17 i/Sebastian for/scribenick: kaz/ 12:17:27 i/MM gives/scribenick: sebastian/ 12:17:41 s/could someone please post the webex coordinate for this teleconference?// 12:17:45 rrsagent, draft minutes 12:17:45 I have made the request to generate https://www.w3.org/2021/03/17-wot-minutes.html kaz 12:18:22 phase 2: may use authentication. There can be queryable database or direct retrieval of TD from Thing 12:18:35 s/phase 2/... phase 2/ 12:19:00 ... we address privacy considerations 12:19:13 ... and security 12:19:32 ... like man-in-the-middle attack 12:20:39 ... we like to have a resolution about next WD update in 2 weeks 12:20:58 Kaz: will be April 7th 12:21:14 topic: Introductions - Toumura 12:22:04 s/topic: Overview/topic: Overview - McCool/ 12:22:24 KT: gives an overview about the 2 phase architecture 12:23:42 ... there are 5 meachanism for discovery like a Core Resource Directory, DNS, Direct, well-Known URI, Decentralized Identifier 12:23:58 s/5 mechanism/5 mechanisms/ 12:24:13 q+ to 1st phase talks about TD of thing or TD of directory. Isn't there a 3rd category (missing)? List of TDs of things? 12:24:20 ... compared to last vF2F we not introduced significant changes 12:24:55 ... update the type ussage in CoRE Link 12:25:13 q? 12:25:20 ... and few editorial changes 12:25:48 ack d 12:25:48 dape, you wanted to 1st phase talks about TD of thing or TD of directory. Isn't there a 3rd category (missing)? List of TDs of things? 12:26:15 ack dape 12:26:29 s/Core R/CoRE R/ 12:26:47 DP: Back to slide 2, I'm wondering if there should be another category like list of TDs? 12:27:11 MM: we like to simple as possible 12:27:36 s/we like to simple/we'd like to be simple/ 12:28:47 ... typically you get one URL 12:29:10 s/simple/as simple/ 12:29:39 q+ I don't understand the difference between "direct" introduction and all the other methods. Do all other methods provide multiple URLs? 12:29:49 q? 12:29:56 q+ benfrancis 12:30:53 MM: we should discuss about the well-known approach about this 12:30:58 ack b 12:31:27 Ben: What is the difference between direct and the other methods? 12:32:25 MM: all provide a URL 12:32:29 q? 12:33:22 q? 12:33:25 q+ 12:34:11 Sebastian: How about RFID or QR-Code scan? 12:35:35 MM: will also provide an URL 12:36:18 KT: we need implementations of the different approaches 12:36:19 q+ 12:36:22 ack s 12:37:04 ... so far no implementation of the DID approach 12:37:32 MM: What kind of implementation WebThing has? 12:37:43 dsr has joined #wot 12:38:05 Ben: we have implemented mDNS 12:38:33 q+ 12:38:40 ack m 12:39:04 ack k 12:39:18 kaz: would confirm 12:39:34 s/confirm/confirm implementations by RIOT OS/ 12:39:43 topic: Exploration Mechanism 12:39:53 Please refer to my last F2F presention for draft API design decisions: https://github.com/w3c/wot/blob/main/PRESENTATIONS/2020-10-online-f2f/2020-10-20-WoT-F2F-Discovery-DirectoryAPI-Tavakolizadeh.pdf 12:40:36 mDNS multicast DNS, and DNS-SD id Service Discovery using DNS (or mDNS) 12:40:44 s/id/is 12:41:03 FT: shows Figure 4 in discovery spec 12:41:32 q+ 12:42:05 ... there two TD classes that are called directory description and link description 12:42:15 dezell has joined #wot 12:42:27 present+ David_Ezell 12:42:54 q+ 12:43:16 ... link description uses the link approach with rel=describedBy 12:43:26 q+ 12:43:39 ML: Is the support TM? 12:44:13 s/topic: Exploration Mechanism/topic: Exploration Mechanism - Farshid/ 12:44:14 MM: not yet. A timing issue. 12:44:22 ack ml 12:44:30 ... maybe in the 2nd version 12:45:19 pb: We already implemented that in RIOT. The rt CoRE topic. Even though we haven't tested that yet. 12:45:22 MM: for the Directory Description the consumer has to follow the links 12:45:48 -> https://w3c.github.io/wot-discovery/#exploration-mech wot-discovery - 6. Exploration Mechanisms 12:45:59 q? 12:46:01 FT: if there are fedorated DD then should be one DD 12:46:04 ack m 12:46:04 ack m 12:46:10 ack b 12:46:47 Ben: is it possible to have a public directory? 12:47:03 .. how about local devices? 12:47:45 dsr has joined #wot 12:48:17 MM: needs security consideration and needs clearify this in this spec. I will create a issue about this 12:48:53 FT: self description is new in the spec 12:49:01 -> https://w3c.github.io/wot-discovery/#exploration-self 6.1 Self-description 12:49:28 ... is an exploration mechanism in which a Thing hosts its own TD 12:50:31 ... TDs can be also provided in partial manner (e.g., for constrained devices) 12:50:38 q+ 12:51:10 -> https://github.com/w3c/wot-discovery/issues/132 wot-discovery - Issue 132 12:51:30 s/Issue 132/Issue 132 - Peer-to-Peer Queries Endpoint in Producers/ 12:52:08 ... there is also a way to query TD elements 12:52:32 q+ 12:53:03 sebastian: In profile discussion it would be good that a consumer can discovery TD with specific TD size 12:53:15 q+ 12:53:16 ack s 12:53:17 q? 12:53:26 ack citrullin 12:53:27 s/haven't tested that yet./haven't tested that yet @@@ (to be moved later)/ 12:53:39 ack m 12:53:41 MM: would be good to cover this. I will provide an issue 12:54:41 Philip: The range is only for HTTP. We want to cover other protocols in the future 12:54:54 -> https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Range Range 12:55:13 s/Range Range/Range Range HTTP request/ 12:55:23 s/request/request header/ 12:55:45 q+ 12:55:55 FT: I cover this topic later in my presentation. 12:56:05 FT: shows the information model of the directory 12:56:26 q+ 12:56:31 -> https://w3c.github.io/wot-discovery/#exploration-directory 6.2 Directory 12:56:35 ... based on a TD https://w3c.github.io/wot-discovery/#directory-thing-description 12:56:48 s/... based/FT: based/ 12:58:24 ... shows the different operation like createTD, updateTD, deleteTD, etc 12:58:25 (I created an issue about allowing HTTP in some cases: https://github.com/w3c/wot-discovery/issues/139) 12:58:34 thanks 12:58:39 -> https://w3c.github.io/wot-discovery/#directory-thing-description Farshid goes through Example 3 12:58:40 q? 12:58:54 q+ 13:00:01 -> https://w3c.github.io/wot-discovery/#exploration-directory-api-registration-listing 6.2.2.1.5 Listing 13:00:24 ... the last part of the dirctory section is Listing 13:01:06 q+ 13:01:10 https://w3c.github.io/wot-discovery/#exploration-directory-api-registration-listing 13:01:50 ... shows an example with content-range 13:01:56 i|the last part|-> https://pr-preview.s3.amazonaws.com/farshidtz/wot-discovery/pull/130.html#exploration-directory-api-registration-listing 6.2.2.1.5 Listing from the preview of PR 130| 13:02:30 s|-> https://w3c.github.io/wot-discovery/#exploration-directory-api-registration-listing 6.2.2.1.5 Listing|| 13:02:45 s/... the last/FT: the last/ 13:02:49 q+ to 10-12 range seems wrong, should be probably 10-11 (for 12 items) 13:02:59 ... there is also some news about validation 13:03:11 s/... shows/FT: shows/ 13:03:13 https://w3c.github.io/wot-discovery/#validation 13:04:34 q+ 13:04:34 -> https://tools.ietf.org/html/rfc7807 RFC7807 Problem Details for HTTP APIs 13:05:06 Ben: I like the approache of pagenation. 13:05:20 ... there some discussion what are properties and what are actions 13:05:20 s/approache/approach/ 13:05:58 ... shall we standardized the interaction names? 13:06:12 ... like "createTDs" ... 13:06:49 s/standardized/standardize/ 13:06:52 ack b 13:07:20 MM: recommend we should standardized the TD / TM. 13:07:32 i|like the|-> https://github.com/w3c/wot-discovery/issues?q=is:issue+is:open+pagination wot-discovery issues related to Pagination| 13:07:42 s/standardized/standardize/ 13:08:12 ack dape 13:08:12 dape, you wanted to 10-12 range seems wrong, should be probably 10-11 (for 12 items) 13:08:23 Ben: disadvantage with current approach is that may multiple interactions needed 13:09:26 MM: this is right, that the current TD approache is quite long. Maybe we should point to a TM. Simpler TD for constrained devices would be good 13:10:46 FT: there are many optional definitions. You do not need to implement all 13:10:55 s/approache/approach/ 13:10:56 q? 13:10:58 ack ml 13:11:30 ML: you define status codes, are thos normativ? 13:11:59 FT: Yes they are normative 13:12:13 ML: are we prepare to handle all of them? 13:12:15 zolkis has joined #wot 13:12:26 FT: there are minimum required 13:13:00 ML: important for the profile discussion 13:13:24 [note the example 3 within this the WoT Discovery spec is informative, the normative codes are defined by RFC7807] 13:13:45 s/normativ?/normative?/ 13:13:45 FT: we have 40x and 50x codes so far 13:13:50 q? 13:14:36 q+ 13:15:07 sk: more protocol specific topics 13:15:15 ... you have syntactic XPath there as well 13:15:26 MM: we should have error codes in seperate section 13:15:26 q+ 13:15:38 ... serialization format for TD is basically JSON-LD 13:15:45 sebastian: wondering about XPath, also working for JSON? 13:17:28 ack s 13:17:31 ack c 13:17:36 FT: its mainly syntactic search with XPath. JSONPath not standardized yet, XPath is just fallback 13:17:46 ack cr 13:17:49 q+ citrullin 13:19:52 zkis has joined #wot 13:20:17 cris: question about pagenation. this approach should take into account different protocols. 13:20:43 q? 13:20:46 ack m 13:21:35 FT: there some discussion in a issue (xxx) about URL approach 13:21:49 ack k 13:22:00 kaz: having a separate section for error 13:22:19 s/different protocols./different protocols. Also it might have impacts to the current design of the scripting api./ 13:22:43 s/error/error definition is fine, but we should be careful about how to deal with the error definition there because we'd like to import the definitions from RFC7807./ 13:23:02 Philipp: I do not see big deal with CoAP. Im worried that your API may kind of complicated to other protocls then HTTP and CoAP. 13:23:02 q? 13:23:08 ack c 13:24:18 MM: currently concentration on HTTP 13:25:12 present+ Zoltan_Kis 13:25:56 Zoltan: there is also discovery in scripting API which is not alligned with WoT discovery yet 13:26:27 ... scripting is only phase 2 and filtering 13:26:37 q? 13:27:43 scribenick. Dape 13:27:52 scribenick: dape 13:28:19 AC: [SLIDES] Syntactic discovery in directories 13:28:49 ... could be semantic not only (syntactic) 13:29:22 ... TD discovery answer: array of TDs 13:29:45 ... JSONPath, mandatory 13:29:57 ... not standard, but widely used 13:30:29 ... e.g., ../jsonpath?query={query} 13:30:47 ... XPATH, version 3.1 13:30:52 ... supports JSON 13:30:56 ... W3C standard 13:31:17 ... e.g., ../xpath?query={query} 13:32:20 ... XPath more complete than JSONPath 13:32:26 ... Pros and Cons 13:32:40 ... Pro 13:32:52 ... - short and expressive 13:33:04 ... - passed as URL 13:33:08 ... Cons 13:33:18 ... - TD fragments 13:33:27 ... - complex queries 13:33:36 ... - JSONPath not standard 13:33:39 q? 13:33:53 MCC: JSONPath on path being an IETF standard 13:33:54 s/issue (xxx)/PR (https://github.com/w3c/wot-discovery/pull/130)/ 13:34:25 AC: ... - JSONPath may lead to security 13:34:52 ... Conclusion: MUST JSONPAth, SHOULD XPath 13:35:18 AC: Semantic Discovery in Directories 13:35:34 ... same idea, answer is JSON 13:35:39 ... result is same 13:35:47 ... SPARQL is optional 13:35:55 q+ 13:35:57 ... SPARQL is W3C standard 13:36:04 .. returns JSON-lD 13:36:20 ... support for: SLECT; ASK; CONSTRUCT, and DESCRIBE 13:36:30 ... *no* support for: UPDATE 13:36:37 s/SLECT/SELECT 13:37:34 ... SPARQL query can be codified as URL 13:37:49 q+ 13:38:01 ... for GET we need codified, for POST we send it in body (without codified) 13:38:05 ... answer is JSON 13:38:09 q+ 13:39:19 ... ASK used to query whether somethnig exists -> results in boolean 13:39:36 q+ 13:39:42 ... DESCRIBE & CONSTRUCT returns JSON-LD 13:40:16 ... DESCRIBE & CONSTRUCT have a problem... are JSON-LD frame documents 13:40:45 ... SPARQL allows us to use query federation 13:41:08 ... e.g., specify to forward it 13:41:49 ... we need to know endpoints ahead of time 13:43:02 ... JSON-LD frames -> translating -> JSON-LD/RDF 13:43:29 ... back to JSON-LD frame is not possible. (needs framing rules) 13:43:46 ... Pros and Cons for SPARQL 13:43:49 ... Pros 13:43:58 ... - expressive 13:44:49 ... - query language with functions etc (W3C standard) 13:45:04 ... - federated queries 13:45:07 ... Cons 13:45:30 ... - simple queries are more verbose tan JSONPath/XPath 13:45:42 ... - consumes more resources 13:45:49 ... Conclusion 13:46:00 ... SPARQL is optional 13:46:16 ... semantic discovery is very flexible 13:46:37 q? 13:47:25 MMC: class-names are visible? And do not match names in spec... cleaning-up? 13:47:28 q? 13:47:30 ack McCool 13:49:05 AC: Yes, if they do not match we should align 13:49:46 q? 13:49:48 SK: Compile SPARQL to URL? is there a limitation in size? 13:49:52 ack se 13:50:02 AC: I am not sure. 13:50:18 ... SPARQL standard defines it 13:51:07 FT: No limit... but there is response code 13:51:17 AC: 100% aligned with SPARQL 13:51:35 CA: Limitation on client-side also? 13:51:50 ... e.g. browser can not handle any length 13:52:28 CA: Which is the difference between what we have and SPARQL 13:52:46 AC: 1. there is no difference 13:52:52 q? 13:53:07 ... 2. the aspect is about framing 13:53:21 ... RDF can be returned 13:53:31 q+ 13:54:16 ... the problem is not SPARQL, we are adding something on top of the standard 13:54:47 SK: Normalized TD. We need to define what we mean by that 13:55:06 ... could be Turtle 13:55:18 ... information is the same 13:55:30 ... form is different 13:55:41 q+ 13:55:44 ... TD task force topic 13:55:58 AC: I created issue w.r.t. that in TD repo 13:56:11 ... normalized for me is RDF 13:56:35 ... simpler form is (framed) JSON-LD 13:56:47 .... problem: framed JSON-LD is not RDF 13:57:05 ... we lack framing rules 13:57:37 MMC: API changes required with such a change? 13:57:48 ... need framing document 13:58:00 AC: mime-type could be used 13:58:08 q? 13:58:43 CA: Could we standardize the process? 13:59:16 AC: worked on this translation 13:59:27 ... did not find generic algorithmn 13:59:34 ack cris 14:00:01 acimmino has joined #wot 14:00:04 https://github.com/w3c/wot-thing-description/issues/1015 14:00:09 PB: Url topic, can we stick do POST only? 14:00:44 ... length/limits 14:01:05 AC: disocvery not mandatory to be used with browser? 14:01:26 MMC: Sometimes we need URL encoding 14:01:40 .. suggest to keep it but put note about length 14:01:58 AC: user can choose 14:02:17 q? 14:02:26 ack citrullin 14:02:34 ack m 14:02:42 ML: Canonical representation 14:03:13 ... we need to seperate the discussion 14:03:19 ... look at it in profile spec 14:03:25 ... just heads-up 14:03:38 MMC: normalized =!= canonical 14:04:07 ... need to clarify what "validation" means.. e.g. SHACL 14:04:22 AC: SHACL should not be applied in queries 14:04:56 MMC: need error response (besides JSON validation) 14:05:29 AC: SHACL/SHAPE ... different with SAREF 14:05:42 ... more ontologies.. more changes 14:06:27 q? 14:06:31 ack McCool 14:06:54 https://github.com/w3c/wot-discovery/issues/143 14:07:22 [10min break] 14:07:23 MMC: --> 9 minute break -> 15 past 14:07:34 s/[10min break]// 14:08:01 rsagent, draft minutes 14:14:45 kaz has joined #wot 14:15:16 rraagent, draft minutes 14:15:18 rrsagent, draft minutes 14:15:18 I have made the request to generate https://www.w3.org/2021/03/17-wot-minutes.html kaz 14:15:22 s/rraagent, draft minutes// 14:15:32 s/rsagent, draft minutes// 14:16:33 TOPIC: Discovery issues 14:17:45 MMC: We talked about framing and pagination already 14:18:06 ... will update slides with links later 14:19:04 MMC: Signing and Canonicalization 14:19:13 ... signing to preserve TD integrity 14:19:23 ... important for directory 14:20:10 ... re-structere TD might break signing 14:20:36 ... canonicalized JSON exists 14:20:53