Registry Working Group

Kickoff Meeting: London: 19-20 March, 2003

Contents:

Registration

Please register at: WhosComingToRegistry19032003

Agenda

Date Time
19th March 2003 10:00 COFFEE/TEA available
  11:00 Introduction Tony Linde
  11:15 Scope - discussion TL
  12:00 GLU Andre Schaaff
  12:20 OAI Andy Powell
  13:00 LUNCH
  14:00 JINI Marco Leoni
  14:20 Metadata Requirements Anita Richards
  14:40 'Must have' Requirements - discussion TL
  15:30 COFFEE/TEA
  16:00 Coverage Clive Page
  16:20 AstroVirtel Alberto Micol
  16:40 AstroGrid Registry Elizabeth Auden, Keith Noddle
  17:00 Work Packages - discussion TL
  17:30 FINISH
 
20th March 2003 09:00 COFFEE/TEA available
  09:45 Introduction TL
  10:00 WP1 - discussion all
  10:30 WP2 - discussion all
  11:00 WP3 - discussion all
  11:30 WP4 - discussion all
  12:00 WP5 - discussion all
  12:30 Next Steps (May meeting) TL
  13:00 FINISH

Note:
40 min presentations will include 15 mins for Q&A
20 min presentations will include 5 mins for Q&A

Location

London e-Science Centre, 19-20 March 2003
South Kensington Campus
Imperial College London
SW7 2AZ
United Kingdom


Travel info

Notes

The meeting kicked off on time but was delayed by problems in getting the telecon working. In the end, Bob set up a NASA telecon link which we used for the rest of the two days. Because of the delays, we fudged the above agenda, dropping all discussions and running the presentations one after the other.

19 March 2003: Presentations

A number of people made presentations on topics related to the VO Registry. I scribbled down a few notes during a couple of the presentations and have added them here. Maybe others who attended can add to these.

GLU

presented by Andre Schaaff: download presentation from below

If we apply the GLU paradigm to REGISTRIES:

The structure would be:

  • there can be several DOMAINS
  • there are a number of running registries (CLIENTS and/or SERVERS for one or several domains, each running a GLU-like deamon)
  • each registry uses as a hook, or entry point to the system
  • the different servers for a domain are listed/authenticated by a MANAGER

Each client has a local dictionary (list of items in its local registry) and also a local copy of all the other definitions in other registries for the domains he has subscribed to.

Update mechanism and propagation:

  • when a server updates its local dictionary, a synchronization mechanism propagates the modification on all dedicated clients

In this scheme:

  • Each data center can be in charge of maintaining locally the description of its own services in its local registry.
  • Services could also be registered via a web interface, on a dedicated deamon, for people who don't want to run a local deamon.
  • When a change is done locally, it is automatically propagated to other registries sharing the same domain.
  • Each registry has a copy of other registries' definitions in the same domain.
  • The system can work whatever the metadata adopted for the actual description of the registry are.

  • questions about UDDI:
    v2 is better and is worth looking at
    there are not enough hooks in it for extensions

OAI

presented by Andy Powell: download presentation from below

  • Andy was member of the Tech Committee which came up with OAI-PMH
  • not comparable to GLU but might be used in conjunction with it
  • its roots are in e-print archives
    • now a more generic standard
  • goal was to harvest metadata into central services
  • 10 key points (see slides)
  • terminology: resource, item, record
  • protocol describes 6 request types
  • utilises Dublin Core (DC)
    • DC very flexible
  • JIESR: JISC Information Environment Service Repository: more akin to VO Registry

In the following discussions, Andy mentioned the idea of using a harvesting method for portals to maintain a cache of registry information so that they do not have to interogate the Registry for every query.

JINI

presented by Marco Leoni: download presentation from below

  • approach to 'self-healing' network
  • lookup service akin to registry
  • metadata can be associated as an object
  • allows search templates
  • issues are that it is Java-specific and is designed for local context

It was agreed that, whether the technology can be deployed as a Registry solution or not, the design may have features that we can adapt or adopt.

Metadata Requirements

presented by Anita Richards: download presentation from below

  • archive catalogs can refer to tabular data, images, spectra
  • key issue: how do we get metadata from the catalogues, headers etc into the registry
  • need extension of UCDs to cover eg frequency resolution
    discussion here determined that the resolution should be a value associated with a UCD rather than each resolution having a separate UCD
  • data quality is another issue: how is it determined and recorded
  • UCDs can evolve from use cases and usage

Coverage

presented by Clive Page: download presentation from below

  • even finest grained registry will only require 1.0E+07 entries (per observation per instrument)
  • how to categorise wavelength: low/high?
  • need to manage unit conversion
  • sparse coverage: ranges, bitmaps, ...

AstroVirtel

presented by Alberto Micol: download presentation from below

  • Science Case (De Grijs)
  • developed work plan
  • constraints based on distance, data quality (how to define quality)
  • need creation of data model for registry

AstroGrid Registry

presented by Elizabeth Auden: download presentation from below

I was out of the room for most of this presentation: perhaps others can contribute. My notes relate to the following discussion.

  • need a registry data model
  • should be able to refer to other entities: non-services

Discussion

We began discussing 'Scope' of the Registry WG.

First thing agreed was what the Registry registered: services or resources. We went for Resources as a more generic name for the entries.

The scope discussion didn't get much further so we agreed to continue the next day with discussion of the seven work packages that I'd defined at the end of my first set of slides.

20 March 2003: Work Packages

The discussion of Day 2 concentrated on each work package, what it should cover and some initial goals. As it happened we dropped from the initial seven WPs to five, as follows. I tended to update the Day 2 slides as we went along so they reflect what was agreed for each WP.

Rwp01: Management, Policy & Documentation standards

Scope:
  • produce documentation template
  • act as liaison with IVOA exec
  • coordinate WP plans and publish integrated set
  • look after policy issues (eg how do Data Centres join the VO registry)

Rwp02: Requirements, Science Cases, Use Cases, Test Cases

Scope:
  • 5-6 science scenarios
  • use cases
  • requirements

Discussion about testing focused on issue of how to 'validate' a registry implementation. Can it be done with a script of tests and expected results or can it be more specific, ie have set of test resources which are added to the registry and baseplate queries are expected to produce set results?

Rwp03: Metadata specs

Scope:
  • define data model (structure and content) for information entered into registry
    • need accompanying explanation
  • define xml schemas for minimum but extensible information in registry (like DC)

Rwp04: Registry replication and interfaces

Scope:
  • security/privacy of metadata
  • how is metadata harvested (into registry & from registry into eg portal cache)
  • query schema
  • maintenance (add/change/delete) schema

There was some discussion about how data centres 'join' the VO registry (or set of registries); this prompted the extension of Rwp01 to include policy issues.

Rwp05: Implementation coordination

This WP began life as one to create a relatively simple reference implementation. It was felt that this was unnecessary given the number of projects underway.

Scope:

  • coordinate implementation of registry standards among VO projects
  • ? create software library
  • ? develop components

Conclusion

  • all communications should be via the Registry mailing list
  • any message on the list should be prefixed with the wp code, eg 'Rwp03: look at my data model'
  • wp leads need to be assertive about getting others to work on topics
  • all Scope documents and Plans to be produced by 11-April
  • TL to update wiki with notes from this meeting (DONE: finally)

Attachments

see below
Topic attachments
I Attachment Action Size Date Who Comment
PowerPointppt AM-IVOA_Registry.ppt manage 67.5 K 2003-03-19 - 11:35 TonyLinde Alberto's slides
PowerPointppt IVOARegistry_Jini.ppt manage 286.5 K 2003-03-19 - 12:04 MarcoLeoni Marco Leoni's slides
PowerPointppt IVOA_Registry.ppt manage 283.5 K 2003-03-19 - 10:20 ElizabethAuden Elizabeth Auden's Astrogrid Registry slides
PowerPointppt IVOA_Registry_oo.ppt manage 103.5 K 2003-03-24 - 23:36 AlbertoMicol Alberto's slides (more compatible?)
PowerPointppt JINIDemo.ppt manage 2495.0 K 2003-03-19 - 21:45 WilliamOMullane Poster about JINI work at STScI
PowerPointppt RegMeeting_1903.ppt manage 307.0 K 2003-03-19 - 11:11 TonyLinde Andre's slides
PowerPointppt RegistryMetadata.ppt manage 35.5 K 2003-03-19 - 18:10 AnitaRichards Anita Richards' slides .ppt
Unknown file formatsxi RegistryMetadata.sxi manage 11.7 K 2003-03-19 - 18:11 AnitaRichards Anita Richards' slides .sxi
PDFpdf ResourceServiceMetadataV6.pdf manage 212.0 K 2003-03-19 - 18:25 BobHanisch V6 of Resource and Service Metadata Definition Doc
PowerPointppt TL-IVOARegistry-Day2.ppt manage 247.5 K 2003-03-20 - 12:12 TonyLinde Tony's slides for Day 2: updated as we went along
PowerPointppt TL-IVOARegistry.ppt manage 260.5 K 2003-03-19 - 16:31 TonyLinde Tony Linde's slides
Unknown file formatxsd VOResource.xsd manage 16.5 K 2003-03-19 - 18:38 RayPlante An XML Schema for the RS metadata
PowerPointppt coverage.ppt manage 49.5 K 2003-03-19 - 16:13 ClivePage Slightly revised 2003 Mar 19 16:15 UT.
PowerPointppt ivoa-ap.ppt manage 189.5 K 2003-03-19 - 11:06 TonyLinde Andy Powell's slides
PDFpdf jini_firewall.pdf manage 151.8 K 2003-03-27 - 14:16 MarcoLeoni http://howto.jini.org/public/howtos/firewalls/
PDFpdf ochsenbein-2000.pdf manage 210.0 K 2003-03-27 - 09:55 SebastienDerriere See part 5.5 for Sky partitioning in VizieR
Topic revision: r35 - 2003-07-04 - MarcoLeoni
 
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