1. WP7: Computation in a shared infrastructure Mark Kettenis JIVE Presented by Norbert Meyer PSNC

2. Partners PSNC ▫ Dominik Stokłosa, Katarzyna Bylec, Szymon Mueller, Mateusz Pabiś OSO ▫ Simon Casey VENT ▫ Karina Krinkele, Normunds Jekabsons JIVE ▫ Aard Keimpema, Mark Kettenis Collaboration with Curtin University in Perth, Australia through CSIRO ▫ …for Global Correlation 2 NEXPReS Period 2 Review – Brussels - September 21, 2012

3. Goals Create an automated, distributed correlator using the global, shared infrastructure of the EVN and its global partners in order to Enable scientists to optimise the use of telescope time to do, for example, surveys and astrometric monitoring programmes realizing that Resources are scarce (staff time, disk pool, correlator time) NEXPReS Period 2 Review – Brussels - September 21, 2012 3

4. How do we realize that? e-VLBI ▫ No impact on disk resources Software correlation ▫ No impact on hardware correlator ▫ Less need for correlator operators Workflow Manager ▫ Limits the impact on telescope operators Distributed computing ▫ Pool resources for larger observations Innovative observation strategies: ▫ Triggers that automatically interrupt background observations NEXPReS Period 2 Review – Brussels - September 21, 2012 4

5. Deliverables NoNo NameTypeDueActualStatus D7.1Workflow Manager requirements from telescope operators Report454 D7.2Workflow Manager requirements from correlator operators Report464 D7.3Workflow Manager implementation Software18194 D7.4Demo of automated correlationDemo24 4 D7.5Real-time middleware components Software24 4 NEXPReS Period 2 Review – Brussels - September 21, 2012 Due in period 1 & 2: 5 Period 1 review: Submit revised project plan addressing initial delay. Submitted end of december: Caught up after D7.3!

6. SFXC: New Features (JIVE) WOLA (Weighted Overlap Add) Windowing ▫ Windowing functions: Rectangular, Hann, Hamming, Cosine Adding other functions is trivial Space Science features ▫ Improved delay tracking for high spectral resolution ▫ Possibility to include Doppler-shift in model Operational tools ▫ weight display, fringe display, clock search tool Webservices ▫ New translation node (data service) for off-line correlation ▫ JSON-based Correlation shifting from Mark 4 correlator to SFXC ▫ All disk-based VLBI correlated on SFXC 6 NEXPReS Period 2 Review – Brussels - September 21, 2012

7. e-VLBI support SFXC supported integrated in jive5ab ▫ Now supports channel dropping, packet reordering jive5ab gained VDIF/VTP support ▫ Accepts the proposed VTP packets ▫ Supports on-the-fly conversion of Mark5B data to VDIF SFXC accepts single-channel multi-thread VDIF ▫ …or single-thread multi-channel VDIF frames Tested at data rates up to 4 Gbit/s ▫ By splitting data into 4 × 1 Gbit/s VDIF/VTP is key to truly distributing correlation over multiple clusters! 7 NEXPReS Period 2 Review – Brussels - September 21, 2012 First e-VLBI fringes at 512 Mbit/s

8. Station Module (OSO) Web service responsible for automating telescope operations Interfaces WfM to VLBI Field System (FS) ▫ Runs on FS PC at each participating station ▫ Written in C ▫ Receives schedules from WfM ▫ Prepares (drudges) ready for FS to use ▫ Starts & stops observations (regular or triggered) ▫ Returns status of FS/antenna Successfully tested at Hartebeesthoek, Onsala, Yebes Sched file PSNC Workflow Manager OSO Station module OSO Station module OSO Station module Field system drudg 8 NEXPReS Period 2 Review – Brussels - September 21, 2012

9. Dynamic schedule creator (OSO) Takes input from several sources ▫ Written in Python ▫ Decider module supplies observation details ▫ Station/antenna details in sets of pre-generated files ▫ Calibrator list parsed from web-form ▫ Produces standard vex file & submits to WfM Some functionality still missing ▫ Logic to select appropriate calibrators & timings Enabler for triggered observations OSO Decider module OSO Schedule writer Calibrator source list Antenna positions Station configs PSNC Workflow Manager Sched file 9 NEXPReS Period 2 Review – Brussels - September 21, 2012

10. E-VLBI Platform (PSNC) e-VLBI Platform – web-based replacement and extension of FABRIC Workflow Manager Simplifies and enhances work of various actors: principal investigators, e-VLBI administrators, correlator operators and telescope operators Dedicated widgets, called portlets, allow to create, submit and monitor e-VLBI observation Build using Liferay portal, which adds out of the box: ▫ Users, authentication and authorization ▫ Roles, permissions, groups, communities ▫ Communication between users (alerts, chat, shared documents) 10 NEXPReS Period 2 Review – Brussels - September 21, 2012

11. Portlets – Experiments (PSNC) Portlet allows to create and submit new experiments Experiment is created based on the provided VEX file 11 NEXPReS Period 2 Review – Brussels - September 21, 2012

12. Portlets – Workflows Graphical presentation of data flow during correlation Based on VEX file and correlator control file; can be edited by user Workflow portlet uses Flex and ActionScript graph library – Flare 12 NEXPReS Period 2 Review – Brussels - September 21, 2012

13. Testbed (PSNC, VENT, JIVE) 13 NEXPReS Period 2 Review – Brussels - September 21, 2012

14. D7.4 Automated Correlation Test on April 18 th (after e-VLBI), with Hartebesthoek and Onsala ▫ Yebes offered to participate as well: wrong frequency ▫ Lots of last-minute fixes Demonstration on May 16 th (after e-VLBI) with Hartebeesthoek, Yebes and Torun ▫ New stations, so some more debugging ▫ Offline correlation happened in June What was demonstrated: ▫ Schedule distribution through e-VLBI platform ▫ Automatically drudged and started by station module ▫ Simultaneous recording and streaming (not yet fully automated) ▫ Real-time correlation; clocks/EOPs inserted in VEX file automatically ▫ Simulated trigger; automatic switch to new schedule Conclusion: ▫ System works but needs to be made more robust 14 NEXPReS Period 2 Review – Brussels - September 21, 2012

15. Conclusions First pilot was run in production environment ▫ Future work will concentrate on higher stability WP7 face-to-face meeting on April 24, 2012 ▫ Between first test and demo; help us fix a lot of issues Deliverables now on schedule 15 NEXPReS Period 2 Review – Brussels - September 21, 2012

16. Research leading to these results has received funding from the European Union's Seventh Framework Programme (FP7/2007 ‑ 2013) under grant agreement n° RI-261525 NEXPReS. This material reflects only the author's views, and the European Community is not liable for any use that may be made of the information contained therein. NEXPReS Period 2 Review – Brussels - September 21, 2012 16