1. EGEE NA4 Lofar Lofar Information System Design OmegaCEN
Kapteyn Institute
TARGET- Computing Center
University Groningen
Orsay, 10 June 2008
Fokke Dijkstra
(most slides by Edwin Valentijn)
EGEE: Lofar

2. LOFAR in short Large distributed radio telescope Two main bands
In NL 2008: initial roll out 20 stations
In NL 2009: 18 central (24 Gbps) + 18 remote (2 Gbps) phased array antenna stations each ~4 soccerfields size
Full scale aperture synthesis array, extends 100 km
Two main bands
High Band ~ 7,500 tiles 120 – 240 MHz
Low Band ~ 7,500 dipoles 20 – 80 MHz
Fibre network, Software Correlator
Run as a broad common-user observatory
Making the transition now from “project” to “observatory”
EGEE: Lofar

3. E-LOFAR Participants
• GLOW:
-- Effelsberg station delivered
-- Garching, Potsdam, Tautenburg stations ordered
--Jülich station federal funding proposal submitted
• LOFAR-UK:
– Chilbolton, Cambridge, Jodrell, Edinburgh
– 1 station funded, site to be chosen
--3 more stations
• Sweden:
– Onsala station funded
+ Poland, Italy, Austria, Bulgaria, Ireland, France
EGEE: Lofar

4. Wires in the field
EGEE: Lofar

5. Station based processing
Input data rate: ~ 460 Gbps
Output data rate: ~ 2 Gbps
Processing capacity: ~ 1.5 Tmul/s
Storage capacity: Gbyte
Receiver
Filter
Beamformer
Buffer
10 GbE
1 GbE
Used for 1 beam & station cross correlation
EGEE: Lofar

6. Lofar: Data Stream EGEE: Lofar
The streams from each station are processed in CIT, Blue Gene/L is a core element of the processing and the data compressed and archived is stored in the Long Tern Archive. The Long Term Archive will increase up to 4TB each year and the target – the Lofar Information System has to store data and supply users with the data as well as provide the data storage for data reprocessing.
The Astro-WISE is an informational system which provides both data storage and data reprocessing for wide field astronomical instruments.
The Astro-WISE is an ideal prototype for the Lofar Information System which must be transferred and adopted to Lofar requests. The main problemis that Astro-WISE works with TB of data – up to 100 TB and we need to make possible to store and operates PB instead of TB.
EGEE: Lofar

7. Lofar Storage
EGEE: Lofar

8. LoWISE design
EGEE: Lofar

9. LoWise- concepts All Tier 1s on an equal footing
Centrally operated GPFS distributed filesystem
File retrieval
Db viewer (web)
Prompt (db query)
Pathname – data server
gLite – Grid ftp
Single distributed db- with all Meta and source data
Valid --Quality -- ready for publication flags
Visibility of data
Owner –Project –Archive --EURO-VO
Authentication / Assigned resources
AstroWISE Oracle system
EGEE: Lofar

10. Processing - options Tier 0 – CP Tier 1 – re-processing Tier 2
Local clusters
EGEE GRID
Tier 2
On Tier 1
Local anarchy
EGEE: Lofar

11. AstroWISE-Up
EGEE: Lofar

12. VST - Virtual Survey Telescope
EURO-VO: GRID and VO

13. TARGET diagram
Extreme data lineage!
EGEE: Lofar

14. Astro-WISE: Services EGEE: Lofar
Astro-WISE interfaces includes CLI, dbviewer, external interfaces, target processor.
EGEE: Lofar

15. Astro-WISE: Grid Computing
The target procesor interface allow the user to reprocess data from the beginning. Here you can see the selection of the computing element which will be used for the processing.
selection of Target in Astro-Wise
storage element defined a priori
EGEE computing
EGEE: Lofar

16. LoWise and Euro-VO
EGEE: Lofar

17. NA4 areas of work Improve integration with EGEE Authentication
Use of Grid certificates through whole chain
Portable client tools
Computing
Portability of software (Python)
Coherent and fast execution of subtasks
Storage
SRM interfaces to Lofar archive
StoRM ?
EGEE: Lofar