2008 NVO Summer School 1

Finding Services in the NVO Registry

Gretchen Greene

THE US NATIONAL VIRTUAL OBSERVATORY

Session Topics

The first part of this session will be a demonstration and follow-along using the new NVO registry web portal

The second part of the session will be a hands on exercise for following some basic java and python client interfaces to the progammatic registry services

2008 NVO Summer School 2

2008 NVO Summer School 3

Registry Web Portal

• Operational NVO Registry is changing functionality to adopt a new standard IVOA schema model– IVOA Registry Working Group– 1.0 VO Resource schema model

• The Registry web portal is a major component to the NVO Search Portal

• We will be working with the following public web portal URL– http://nvo.stsci.edu/vor10

• NVO Home page reflects an earlier prototype. It will remain in operation yet soon to be phased out as the primary registry

2008 NVO Summer School 4

Out with the old….

In with the New….

2008 NVO Summer School 5

Registry Portal Search

• Keyword Search input– Space separated text input

• Example 1: binary star• Example 2: galex• Example 3: HEASARC

– The default combination of entered keywords is boolean ‘AND’ (‘OR’ future enhancement)

• Full text database index– Scans through all the standard VO Resource

metadata for a contains string match• Newly published resources may not appear

immediately (~ 15 min delay)

• Will not perform direct Spatial query or source name resolution (See NVO Search Portal)

2008 NVO Summer School 6

Registry Advanced Search

• Advanced – very basic search interface that allows sql like predicate query – Allows more refined search criterion– Search for service specific, capability,

resources– Current limitation: partial ADQL

implementation and full compliance will be in the future

• See link for metadata tags available

2008 NVO Summer School 7

Search Results Table

• Keyword search results Tabular View– Reformats VO Resource metadata into VOTable

representation– Subset of full resource metadata in this view

• Tabular information is arranged in a javascript filterable and sortable format– Consistent with NVO Search Portal application views and is

based on a shared library• STScI HLA VOView available via NVO Trac SVN

• Table columns may be changed using the column control list at the bottom of the page

• Each Row represents a single Resource

2008 NVO Summer School 8

Table Filtering and Sorting

• Filtering allows wildcard (*) for partial matching

• Examples using the keyword ‘galex’– Example: *hubble* on title column– Example: *gr1* on shortname– Example: *skynode* on identifier column

• The filter or sort is applied to the full table, not the page only view

• Columns can be sorted before or after the filtering

2008 NVO Summer School 9

Service Metadata

• Service Capabilities are mapped into user friendly service “category” descriptions:– Images, catalog, spectra, http request, web

page, custom, …– Correspond to VO DAL protocols– Note the original NVO registry contains jargon in

VO standard service terms• e.g. simple image access, SIAP, SSAP, skynode,

tabularskyservice….

• Resources may be COMPOSITES of multiple service types

2008 NVO Summer School 10

Service Categories

• Category column represents a generic service type definition– Catalog: Cone Search– Images: Simple Image Access Protocol (SIAP)– Spectra: Simple Spectral Access Protocol (SSAP)

• Additional types of Resource interfaces available:– includes NON STANDARD VO services– Web page, http request, CEA (Astrogrid

Workflow), Custom…

2008 NVO Summer School 11

Service Portal Data Access

• Catalogs and Images are accessible through a link to Simple Data Query– Search Me link appears under Browse/Query

column

• All service types provide interface access URL which are listed in the column accessURL– Invocation requires a priori knowledge of

standard protocol implementation

2008 NVO Summer School 12

Full Resource Metadata

• Click on ‘Full Resource’ link for a row in the Search results table

• Stylized version of the complete set of metadata is viewable under Full Record

• Service data access also available through the Search Me link – under the section on Service Interfaces

• The complete VO Resource XML instance can be viewed by clicking on the View XML link– Need to have associated app for xml viewing

2008 NVO Summer School 13

Results Save or Send Features

• The keyword search results can be downloaded and saved to the desktop in various formats.

• For direct exchange between the Registry search results and other VO Portal Applications, you can “Send Results to” VIM, Datascope or Inventory– Automatically will transfer result table

resources to these web applications

2008 NVO Summer School 14

Developers - Registry Clients

• The registry has 3 sets of web service programmatic interfaces that are based on– IVOA standard Registry Interface 1.0

• http://nvo.stsci.edu/vor10/ristandardservice.asmx

– NVO Registry Portal service interfaces• http://nvo.stsci.edu/vor10/NVORegInt.asmx

– IVOA Registry Open Archives Initiatives (OAI) harvesting service

• http://nvo.stsci.edu/vor10/STOAI.asmx

2008 NVO Summer School 15

Registry Interface 1.0

• A standard IVOA SOAP WSDL defines a set of functions for accessing and querying registry resources – W3C web service protocol

• Client applications can develop code which is independent of IVOA registry implementation– To interface with a fully searchable registry

• Contains harvested resources from all RofR publishing registries

• Additional reference documentation located on the IVOA TWiki site or NVO Book – Registry Client

2008 NVO Summer School 16

NVOSS Registry Client Software

• NVOSS software library contains sample sets for developing registry client software– JAVA version for IVOA Standard Search

Interface:• NVOSS_HOME/java/src/ivoaregistry

– Python version for IVOA Standard Search Interface and NVO Search Portal service interface:

• NVOSS_HOME/python/src/registryClient

2008 NVO Summer School 17

Getting Started

Click on the link for this session program for Client EXERCISE.

2008 NVO Summer School 18