tap service at esac - votap carlos rios diaz science archives team (sat) esa-esac, madrid, spain...
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TAP service at ESAC - VOTAP
Carlos Rios Diaz
Science Archives Team (SAT)
ESA-ESAC, Madrid, Spain
VOTAP
Presentation Overview
Getting started
Architecture
Service Capabilities
Use cases
Future expectations
References
VOTAP – Getting started (1 / 2)
• http://code.google.com/p/opencadc
• Adaptation to our needs and solving some issues during the process
• Building of our own TAP service to make (in principle) 2XMMi and AKARI catalogues available
Starting point: published code from the Canadian Astronomy Data Centre (CADC)
ESAC Aerial view
http://www.esa.int/SPECIALS/ESAC/
Planning to make more catalogues available in a future
VOTAP – Getting started (2 / 2)
Added some extensions and new functionality, such as the following items:
• Set of mathematical and trigonometrical functions (100% ADQL compliant) supported
• 100% geometrical functions ADQL compliant supported
– Related to asynchronous performance (optional within TAP spec):
• Modifiable parameters for a job ( MAXREC, LANG, QUERY and FORMAT)
• Job deletion from user request
• Daemon checking destruction dates for every job to delete the expired ones
Our source code is available at: http://code.google.com/p/esavogpl (VOTAP)
Remaining features to offer this source code as a toolkit
• Pending of a collaboration with other groups
• Automation of data ingestion
• Abstracting it from dependence on a specific database
Presentation Overview
Getting started
Architecture
Service Capabilities
Use cases
Future expectations
References
VOTAP - Architecture
Web service using Apache Axis 2 v1.4.1
Java JDK 1.6
Tomcat application server v6.0 with Java Virtual Machine 1.6
Database: PostgreSQL 8.3 with PgSphere extension
Easy access to the service (sync and async ways) and asynchronous job management, simply typing the proper URL in your favorite web browser
Easy addition of new catalogues
Only a data ingestion of the sources and their parameters are needed to subscribe a new catalogue
VOTAP - Architecture
Asynchronous performance schematics
Presentation Overview
Getting started
Architecture
Service Capabilities
Use cases
Future expectations
References
VOTAP – Service Capabilities
The service offers the following capabilities:
– Checking of the service availability (if up or down)
– Published schemas
– Published tables on each schema
– Published columns for each public table
To launch queries:
Synchronous (sync) performance
Asynchronous (async) performance
All of this can be consulted on http://193.147.153.158/votap/services/TapService/capabilities
Presentation Overview
Getting started
Architecture
Service Capabilities
Use cases
Future expectations
References
VOTAP – Use case on 2XMMi catalogue
Use case #1
• Search sources in a circle over 2XMMi catalogue
[ using synchronous performance and an output restricted to 10 items ]
http://193.147.153.158/votap/services/TapService/sync?REQUEST=doQuery&LANG=ADQL&QUERY=select c.ra, c.dec from tap_schema.source_cat_epic as c where ( INTERSECTS(CIRCLE('ICRS GEOCENTER', 10.5, 41, 1),POINT('ICRS GEOCENTER', c.ra,c.dec))=1)&MAXREC=10
VOTAP – Use case on AKARI catalogue (1 / 2)
Use case #2
Positional crossmatch between 2XMMi and II_298_FIS AKARI
[ using asynchronous performance and an output restricted to 10 items ]
1st step: create the job (*)
• http://193.147.153.158/votap/services/TapService/async?REQUEST=doQuery&LANG=ADQL&QUERY=select c.ra, c.dec, f.RAJ2000, f.DEJ2000 from tap_schema.source_cat_epic as c, tap_schema.II_298_fis as f where(INTERSECTS(CIRCLE('ICRS GEOCENTER', f.RAJ2000, f.DEJ2000, .1),CIRCLE('ICRS GEOCENTER', c.ra, c.dec, .1))=1)&MAXREC=10
• * Annotate the JOB ID given as the result of the job creation
2nd step (optional) : Check the new job is already included into the job list for the servicehttp://193.147.153.158/votap/services/TapService/async
3rd step (optional) : Watch the parameters for the job (**)
http://193.147.153.158/votap/services/TapService/async/JOB_ID/parameters
** substituting JOB_ID for the given ID
VOTAP – Use case on AKARI catalogue (2 / 2)
4th step: Running the job• http://193.147.153.158/votap/services/TapService/async/JOB_ID/phase?PHASE=RUN
5th step : Checking the job execution phase (until it will be COMPLETED or ERROR)• http://193.147.153.158/votap/services/TapService/async/JOB_ID/phase
6th step : According to the updated execution phase, view the result for the process:
– If COMPLETED without errors:http://193.147.153.158/votap/services/TapService/async/JOB_ID/result
– If ERROR:http://193.147.153.158/votap/services/TapService/async/JOB_ID/error
Presentation Overview
Getting started
Architecture
Service Capabilities
Use cases
Future expectations
References
VOTAP - Future Expectations
• Idea of releasing to the community a developer-friendly project as a toolkit to be able to construct TAP services
– Abstracting it from dependence on the PostgreSQL database (and its geometrical extension Pgsphere)
• Initiate a collaboration as a three-party enterprise
– Involved CADC – Spanish VO – ESAVO
– Sharing resources
– Avoiding many distinct branches
– To unify in a single way
Presentation Overview
Getting started
Architecture
Service Capabilities
Use cases
Future expectations
References
VOTAP - References
International Virtual Observatory Alliance (IVOA)
www.ivoa.net
Astronomical Data Query Language (ADQL) version 2.0, IVOA recommendation 30th October 2008
www.ivoa.net/Documents/ADQL/2.0
Table Access Protocol (TAP) version 1.0, IVOA recommendation 27th March 2010
www.ivoa.net/Documents/TAP/1.0
STC Space-Time Coordinate Metadata for VO version 1.33, IVOA recommendation 30th October 2007
www.ivoa.net/Documents/cover/STC-20071030
VOTable Format Definition version 1.2, IVOA recommendation 30th November 2009
www.ivoa.net/Documents/VOTable/1.2