Operations IG, IVOA Interop, 3 Nov 2021

Wed Nov 3, 0630 UTC
Participants: 38

Christophe Arviset: Euro-VO Registry weather report

Upcoming Euro-VO Registry 3.0 - Nov 2021
Simplified approach for service compliance validation runs
twice monthly runs

Validators for SCS v1.03, SIA v1.0&2.0, SSA v1.1
Validating TAP v1.0 & 1.1 using TAPlint

SCS: most services are compliant
SIA v1: ~half services are fully compliant, most are partial
SIA v2: higher percentage of compliance than v1

SIA v1 common problems:
    - exactly one field must have ucd='POS_EQ_RA_MAIN' with datatype double
    - exactly one field must have ucd='VOX:Image_Naxes', datatype int
    - test query gives no results, or are base64 encoded (not yet supported by validator)

MD: arraysize=1 ought to be dropped, but other than that, I´m totally in favour of a list of proposals for dropped requirements.  But how do we get going?

SIA2 common problems:
    - no results and no testquery
    - incorrect error code
SSA common problems:
    - access reference URI used to access the dataset
    - [..?] no data model
    - [?] position specified multiple times
TAP - low percentage of full compliance
    several different error types

Tom D: is EuroVO validator checking VOTable version? yes supports up to v1.3
(Tom D heard consensus that modern versions of VOTable *should* be acceptable in practice for SCS responses even though the standard specifies 1.0 or 1.1.  An erratum could make that explicit.)
Markus D: using the MAST and Paris validators, noting that results can be inconsistent across validators. likes the REST API to the validators, to not have to dig through the web pages.
Christophe A: regarding inconsistencies, not coordinating with other validators, independent interpretation of the standard.
SG: are we not better off to have independent implementations? and when they arent giving the same answers, we should figure out why?. MT made similar comment.
Christophe A: if the validators are reporting errors that are 'too picky' or unimportant, perhaps those issues should be reduced to suggestion rather than requirement.
Pierre L: validator authors might consult one another for areas when issues are not consistently reported, to see where more checking may be desirable

Tamara Civera: Validators in VO services development workflow

Importance of testing automation. 
can IVOA validators be included in automatic tests?
which features should be integrated?

Validators must be machine accessible, errors machine readable (xml, json...)

Validators need to be well documented, and have access to dev environments where services are being developed

MT: re TAPlint, are there features desired that are missing now? (may follow up offline)
Tamara: Yes, TAPlint has the features desired because it can be used easily in the automated test. It can be called by machines and the json result is nice to be read by them. In the next months I want to integrate it in my TAP services tests so after it I can send you my feedback about this process. But there are other services like cone search or SIAP whose validators difficult to be integrated in these automated tests.

Christophe A: thanks for suggestions, will put in list for EuroVO

MD - VO Paris, validator has nice feature for putting test descriptions in JSON files. useful to have a standard for how to express the tests you want to run. Paris toolchain may be a good start.
Tamara: Is there any documentation about the Paris validators REST API?

Mark Taylor: Report on UCD and VOUnit usage in the VO

Column metadata vocabularies used for annotation of columns: VOTable, TAP service metadata, VODataService instance in the registry or TAP /tables endpoints

UCD standards: UCD1 (dated? pre-2004) , UCD1+ rec 2018, endorsed note 2021
UCD1+ is not required, but good practice.

VOUnit standard
VOTable 1.4 encourages use of VOUnits, earlier are less clear.
Use of VOUnit not required, but good practice

Unity: parsing/validation library , Norman Gray, >2014
Ucidy: UCD1+ parsing/validator library, G. Mantelet >2017
Incorporated in STILTS/TOPCAT, TAPlint, votlint
(see slides for useful examples using STILTS/TOPCAT functions)

(example output posted to wiki)

Providers: use diagnostics, review results, impove metadata
Semantics WG: review results, consider standards adjustments?
Authors: make sure that mandated UCDs/Units are legal

In VizieR, units specified in square brackets indicates log(unit) - allowed in VOUnits