IVOA Interop April 2022
Operations IG 2: Operational Status
Date: Fri April 29 2022, 20:30 UTC
Participants: (52)
Raffaele D'Abrusco: The VO at the Chandra X-Ray Center
Why did Chandra embrace the VO?
- preexisting local concerns on topic of data and metadata standardization
- leveraging existing &community tools for shared problems
- efficiency - concentrating on implementation and operation instead of design
- interoperability - data, services, interfaces
CXC has been involved in many IVOA-related projects - standards, tools, infrastructure, organization. investments in time&effort
Growth - Chandra operating for >20yrs, pointed obs with small FOV, some areas visited many times
coverage lends to catalogs, classification of objects.
archive VO services provide access to both observation and compiled products - catalogs, area coadds
CXC in some cases has deployed services soon after standards, others have been a little later
Recent usage heavily dominated by ConeSearch on source catalog. large spikes in usage, driven by heavy requests from few users.
TAP and SIAP are more stable levels of usage
Some hints of proposal-related seasonality
some users mining the archive inefficiently, pulling all products for each source, many (~1B) sources
lessons:
- shift focus from in-house interfaces to support of external interfaces - stay more current with changing needs of community
- experience with community interactions has highlighted some potential areas for improvement
- ex: ObsCore doesn't differentiate between "center of obs" vs "target coord", for off-axis observations. class, mode, cycle of observations
- multigenerational IVOA presence
future
- expand services
- housekeeping - keep up to date, improve existing
- feedback to IVOA - improvings standards
- promoting VO practices in parent organization SAO
Sebastien Derriere, Gilles Landais: VOUnits in VizieR
Reporting on usage of VOUnits
Nov 2021 feedback suggested actions to review compliance with standards
Vizier has standards for catalogs: http://vizier.u-strasbg.fr/doc/catstd-3.2.htx
with some additions and flexibility. "style guide" for how best to select units
completeness: 805K columns in VizieR, 442K with non-empty units. 2208 distinct expressions for <<unit>>
VOTable 1.4 requires VOUnits for contents of unit="", need new piece of metadata in METAcol table <<vounit>> column being added (compliant unit)
N.Gray's "unity" library for parsing, M. Taylor "stilts" for validation
parsing errors - grammar too restrictive? some things should be allowed flagged as errors (e.g. Sun, %, log(factorUNIT)
Improvements: translation of exponentiation, numerical factors, some symbols, and changes to parser greatly reduced claimed errors, from 26% to 0.5%
issues with sexigesimal support
issue with units on string-valued quantities (e.g. sexigesimal notation containing colons)
suggest possible erratum to VOUnit standard, also upgrade validators
work in progress - can we get to 99.9% compliance
Renaud Savalle: PADC Web Validators
Web validator: run interactively by user at website
Testing framework - website providing links to results of tests for a class of services
web api - provide test results in a programmatic way
implements tests from rules and constraints, derived from IVOA Recs
should call service respecting IVOA SoftID
Legacy validators - VOT, SCS, SIA, SSA, SLA
Recent changes
- VOTable - COOSYS
- SSA - base URL trailing separator
- SIA (for Datalink) RESOURCE with type="metadata" always allowed, at least one type="results" required
TAP validator has been entirely rewritten
- uses taplint - M. Taylor
- new parser& we validator
- output in color
- ..
New HiPS web validator
- uses Hipslint from CDS P. Fernique
- ..
web frontend https://voparis-validation-reports.obspm.fr/validators/home
new features
- new table display
- SIA2, HiPS added to daily batches
- ...
VOParis validators can be invoked via website, get a report. useful to debug/improve service and see feedback live
Renaud Savalle: PADC Weather Report
Weather report - how are services faring with validator compliance?
seeing general improvement over time with compliance
Cone Search
- common errors with retrieval, timeouts
- also xml compliance
- other things less frequent
SIAV1 common errors
- unsupported namespace, error loading, missing DTD
- again XML formatting/compliance issues
SSA common errors
- warning - only one URI (one provider using wrong schema location)
SIAv2
- XML issues with field attributes
TAP
- many different types of errors happening
- details in presentation
HiPS
- sometimes index and properties don't match
- recommended keywords missing
- other warnings
- list in presentation
- Many known HiPS providers are not listed in VO registry, they should add themselves
Service providers, please be proactive and check compliance
https://voparis-validation-reports.obspm.fr/validators/home <= Web Validators
https://voparis-validation-reports.obspm.fr/ <= Testing Framework
https://voparis-validation-reports.obspm.fr/api/ <= Web API