1. NEXPReS Period 3 Overview WP8 FlexBuff High-Bandwidth, High-Capacity Networked Storage Ari Mujunen Aalto University Metsähovi Radio Observatory Finland Research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007- 2013) under grant agreement n° RI-261525. This presentation reflects only the author's views. The European Union is not liable for any use that may be made of the information contained therein.

2. Introduction WP8 leader ▫ Ari Mujunen ▫ Aalto University Metsähovi Radio Observatory, Finland ▫ WP8 FlexBuff  Or originally in DoW “Provisioning High-Bandwidth, High- Capacity Networked Storage on Demand” WP8 FlexBuff explores ways to implement ▫ on-demand ▫ networked Storage to match the ▫ multi-Gbps bandwidth and ▫ petabyte-class capacity Requirements of VLBI of today and tomorrow ▫ in a distributed fashion Slide: 2 NEXPReS P3 Review – Dwingeloo, NL - 19 September 2013 WP8 FlexBuff

3. FlexBuff Concept Recording high-speed 4—8Gbps UDP streams while simultaneously reading the same disks with high-speed remote UDP streaming Run on highly COTS Linux hardware with ▫ Plenty of SATA disks, standard controllers ▫ One or more 10 Gbps Ethernet connections Combines real-time e-VLBI data taking with flexibility in accessing the data Slide: 3 NEXPReS P3 Review – Dwingeloo, NL - 19 September 2013 WP8 FlexBuff

4. Overall Schedule The three periods of the project each have had their own role in the development cycle of FlexBuff ▫ P1: Explore / try /rank / select technical solutions  “Find what probably would work” ▫ P2: Develop sw, deploy, and test proto hw/sw  “Make it work” ▫ P3: Integrate parts into a prototype system  “Make it work smoothly all the time” Slide: 4 NEXPReS P3 Review – Dwingeloo, NL - 19 September 2013 WP8 FlexBuff

5. Overview of deliverables D#TitleTypeLeadDue D8.08Design document of integration system of allocation methods with transparent multi-Gbps access ReportJIVE 26 D8.09Integration test report of LTA and pipeline integrationReportASTRON 32 D8.10Demonstration tests of the integrated systemDemoJIVE 32 D8.11Final report on Networked Storage on DemandReportAALTO 35 Slide: 5 NEXPReS P3 Review – Dwingeloo, NL - 19 September 2013 WP8 FlexBuff All P3 deliverables were completed well before period end

6. D8.08 Design document of integration system of allocation methods with transparent multi-Gbps access Or, in plain language, “Design of Integration & Tests” The title should have been simpler already in DoW… Outlines the design with which the FlexBuff can be integrated into VLBI observation system so that realistic multi-station tests at high data rates can be performed in D8.10 Lead by JIVE, with assistance from AALTO ▫ And from test participants (INAF, OSO, UMAN) Slide: 6 NEXPReS P3 Review – Dwingeloo, NL - 19 September 2013 WP8 FlexBuff

7. D8.09 Integration test report of LTA and pipeline integration Report Includes several tests with a prototype system Can the FlexBuff concept and “vlbi-streamer” software quickly stream out portions of the LOFAR Long-Term Archive (LTA) data to locations closer to data computing facilities? ▫ Yes, it can! Lead by ASTRON, assistance from AALTO ▫ TCP mode added to “vlbi-streamer” Slide: 7 NEXPReS P3 Review – Dwingeloo, NL - 19 September 2013 WP8 FlexBuff

8. D8.09 LOFAR LTA Tests Slide: 8 NEXPReS P3 Review – Dwingeloo, NL - 19 September 2013 WP8 FlexBuff

9. D8.10 Demonstration tests of the integrated system Demonstration An additional brief report was produced Demonstrates that the integrated FlexBuff system works ▫ Two demo setups:  “e-Merlin” test: record 8x 512Mbps, buffer, and transmit the resulting 4Gbps over a slower 1.6Gbps link  5-site “SFXC test”: emulated as closely as possible a typical EVN high-rate station configuration Lead by JIVE, participation of AALTO, INAF, OSO, UMAN Assistance & cooperation with: ▫ WP6: BoD for connections ▫ WP7: SFXC software correlator for verification of transfers Slide: 9 NEXPReS P3 Review – Dwingeloo, NL - 19 September 2013 WP8 FlexBuff

10. D8.10 Setups Slide: 10 NEXPReS P3 Review – Dwingeloo, NL - 19 September 2013 WP8 FlexBuff Setup 1: “e-Merlin” ▫ Multiple simultaneous 0.5Gbps streams ▫ Buffering to overcome limited 1.6Gbps connectivity Setup 2: “Multi-station” ▫ Four stations sending buffered data to JIVE for immediate corr ▫ Simultaneously recording >>4Gbps local data ▫ Verified using WP7 SFXC software correlator

11. D8.11 Final report on Networked Storage on Demand A comprehensive summary report of the ▫ design principles, ▫ development process, ▫ internal architecture, and ▫ experimental performance of the “vlbi-streamer” data acquisition software running on COTS Linux systems Lead AALTO, contributions from all partners ▫ Compiled by the lead author of “vlbi-streamer” software Slide: 11 NEXPReS P3 Review – Dwingeloo, NL - 19 September 2013 WP8 FlexBuff

12. Overall End Results Over the 3-year NEXPReS project, the WP8 FlexBuff team was able to: ▫ Identify suitable COTS Linux systems which  When equipped with “matching” data acquisition software ▫ Can sustain multiple high-rate r/w streams of network data and ▫ Offer substantial amounts of storage to locally buffer acquired data for later processing Multiple concurrent read/write streaming obliterates the need to predetermine (early, during scheduling) whether a given observation will be correlated ▫ Immediately while observing (in e-VLBI mode) or ▫ Later—even reprocessing of an e-VLBI mode observation later  Even with as many recorrelations as may be required Slide: 12 NEXPReS P3 Review – Dwingeloo, NL - 19 September 2013 WP8 FlexBuff

13. Future? Re-evaluation of COTS hardware options ▫ Effectively an update of D8.2 Further integration of “vlbi-streamer” software into other software components of the VLBI observation system ▫ Jive5ab, SFXC, FS,… Looking into ways of optimally taking advantage of multiple FlexBuffs ▫ Both at a given VLBI station and also ▫ Globally, VLBI network-wise Slide: 13 NEXPReS P3 Review – Dwingeloo, NL - 19 September 2013 WP8 FlexBuff

14. Questions/Comments Contact Information: ▫ Ari Mujunen ▫ Laboratory Manager at: ▫ Aalto University Metsähovi Radio Observatory ▫ Ari.Mujunen@aalto.fi Ari.Mujunen@aalto.fi ▫ Additional information available via http://www.nexpres.eu/ NEXPReS is an Integrated Infrastructure Initiative (I3), funded under the European Union’s Seventh Framework Programme (FP7/2007- 2013) under grant agreement no RI-261525. Slide: 14 NEXPReS P3 Review – Dwingeloo, NL - 19 September 2013