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SKA The worlds largest Radio Telescope streaming data processor. Dr Paul Calleja Director Cambridge HPC Service. Overview. Introduction to Cambridge HPCS Overview of the SKA project SKA streaming data processing challenge The SKA SDP consortium.
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SKA The worlds largest Radio Telescope streaming data processor Dr Paul Calleja Director Cambridge HPC Service
Overview • Introduction to Cambridge HPCS • Overview of the SKA project • SKA streaming data processing challenge • The SKA SDP consortium
The University of Cambridge is a world leading teaching & research institution, consistently ranked within the top 3 Universities world wide Annual income of £1200M - 40% is research related - one of the largest R&D budgets within the UK HE sector 17000 students, 9,000 staff Cambridge is a major technology centre 1535 technology companies in surrounding science parks £12B annual revenue 53000 staff The HPCS has a mandate to provide HPC services to both the University and wider technology company community Cambridge University
Four domains of activity Driving Discovery Advancing development and application of HPC HPC R& D Commodity HPC Centre of Excellence Promoting uptake of HPC by UK Industry
Cambridge HPC vital statistics • 750 registered users from 31 departments • 856 Dell Servers - 450 TF sustained DP performance • 128 node Westmere (1536 cores) (16 TF) • 600 node (9600 core) full non blocking Mellanox FDR IB 2,6 GHz sandy bridge (200 TF) one of the fastest Intel clusters in he UK • SKA GPU test bed -128 node 256 card NVIDIA K20 GPU • Fastest GPU system in UK 250 TF • Designed for maximum I/O throughput and message rate • Full non blocking Dual rail Mellanox FDR Connect IB • Design for maximum energy efficiency • 2 in Green500 • Most efficient air cooled supercomputer in the world • 4 PB storage – Lustre parallel file system 50GB/s • Run as a cost centre – charges our users – 20% income from industry
Dell | Cambridge HPC Solution Centre • The Solution Centre is a Dell Cambridge joint funded HPC centre of excellence, provide leading edge commodity open source HPC solutions.
SA CHPC collaboration • HPCS has a long term strategic partnership with CHPC • HPCS has been working closely with CHPC for last 6 years • Technology strategy, system design procurement • HPC system stack development • SKA platform development
Square Kilometre Array - SKA • Next generation radio telescope • Large multi national Project • 100 x more sensitive • 1000000 X faster • 5 square km of dish over 3000 km • The next big science project • Currently the worlds most ambitious IT • Project • First real exascale ready application • Largest global big-data challenge
SKA location A Continental sized Radio Telescope • Needs a radio-quiet site • Very low population density • Large amount of space • Two sites: • Western Australia • Karoo Desert RSA
SKA phase 1 implementation + SKA1_Mid incl MeerKAT SKA1_AIP_Survey incl ASKAP SKA1_Low
SKA phase 2 implementation SKA2_AIP_AA SKA2_Low SKA2_Mid_Dish
What is radio astronomy s Astronomical signal (EM wave) Detect & amplify B 1 2 Digitise & delay Correlate X X X X X X Integrate SKY Image Process Calibrate, grid, FFT
SKA – Key scientific drivers • Evolution of galaxies • Exploring the • dark ages • Pulsar survey • gravity waves • Cosmic Magnetism • Cradle of life
But…… Most importantly the SKA will investigate phenomena we have not even imagined yet
SKA timeline 2022 Operations SKA1 2024: Operations SKA2 2023-2027 Construction of Full SKA, SKA2€2 B 2017-2022 10% SKA construction, SKA1€650M 2012 Site selection 2012 - 2016 Pre-Construction: 1 yr Detailed design€90M PEP 3 yrProduction Readiness 2008 - 2012 System design and refinement of specification 2000 - 2007 Initial concepts stage 1995 - 2000 Preliminary ideas and R&D
SKA project structure SKA Board Director General Advisory Committees (Science, Engineering, Finance, Funding …) Project Office (OSKAO) Locally funded Work Package Consortium n Work Package Consortium 1 …
Work package breakdown • System • Science • Maintenance and support /Operations Plan • Site preparation • Dishes • Aperture arrays • Signal transport • Data networks • Signal processing • Science Data Processor • Monitor and Control • Power SPO UK (lead), AU (CSIRO…), NL (ASTRON…) South Africa SKA, Industry (Intel, IBM…)
The SDP consortium led by Paul Alexander University of Cambridge 3 year design phase has now started (as of November 2013) To deliver SKA ICT infrastructure need a strong multi-disciplinary team Radio astronomy expertise HPC expertise (scalable software implementations; management) HPC hardware (heterogeneous processors; interconnects; storage) Delivery of data to users (cloud; UI …) Building a broad global consortium: 11 countries: UK, USA, AUS, NZ, Canada, NL, Germany, China, France, Spain, South Korea Radio astronomy observatories; HPC centres; Multi-national ICT companies; sub-contractors SKA = Streaming data processor Challenge
Discussions under way with DelI, NVIDIA, Intel, HP IBM, SGI, l, ARM, Microsoft Research Xyratex, Mellanox, Cray, DDN NAG, Cambridge Consultants, Parallel Scientific Amazon, Bull, AMD, Altera, Solar flare, Geomerics, Samsung, CISCO Apologies to those I’ve forgotten to list SDP –strong industrial partnership
SKA data rates 20 Gb/s 4Pb/s 16 Tb/s 24Tb/s 1000Tb/s 20 Gb/s
Science data processor pipeline Corner Turning Course Delays Fine F-step/ Correlation Visibility Steering Observation Buffer Gridding Visibilities Image Storage Imaging: Imaging HPC science processing Switch Buffer store Switch Buffer store Bulk Store Incoming Data from collectors Image Processor Correlator Beamformer UV Processor … Corner Turning Course Delays Beamforming/ De-dispersion Beam Steering Observation Buffer Time-series Searching Search analysis Object/timing Storage Non-Imaging: 10 Tb/s 200 Pflop 10 Eflop 10 Pflop 1 Eflop 100 Pflop SKA 1 1 EB/y 50 PB 10/1 TB/s 1 Eflop SKA 2 10 EB/y 1000Tb/s 10 Tb/s Software complexity
SDP processing rack – feasibility model GGPU, MIC,…? 42U Rack Processing blade 1 Processing Blade: Processing blade 2 Processing blade 3 Disk 1 ≥1TB Disk 2 ≥1TB Disk 3 ≥1TB Disk 4 ≥1TB Processing blade 4 M-Core - >10TFLOP/s M-Core - >10TFLOP/s Processing blade 5 Processing blade 6 56Gb/s Processing blade 7 Processing blade 8 Host processor Multi-core X86 Processing blade 9 To rack switches Processing blade 10 Leaf Switch-1 56Gb/s Leaf Switch-2 56Gb/s Processing blade 11 Processing blade 12 PCI Bus Processing blade 13 Processing blade 14 Blade Specification Processing blade 15 • 20 TFlop • 2x56 Gb/s comms • 4 TB storage • <1kW power • Capable host (dual Xeon) • Programmable • Significant RAM Processing blade 16 Processing blade 17 Processing blade 18 Processing blade 19 Processing blade 20
SKA feasibility model 1 2 16 HPC 1 … AA-low Data 1 1 2 3 N … Imaging Processor … 280 … 56Gb/s each … 1 … AA-low Data 2 … … 280 … Switch … … 1 AA-low Data 3 … … 280 … Bulk Store … 1 … Dishes Data 4 … … 250 Further UV processors Corner Turner switches Correlator/ UV processor
SKA Open Architecture Lab • HPC development and prototyping lab for SKA • Coordinated out of Cambridge and run jointly by HPCS and CHPC • Will work closely with COMP to test and design various potential compute, networking, storage and HPC system / application software components • Rigorous system engineering approach, which describes a formalised design and prototyping loop • Provides a managed, global lab for the whole of the SDP consortium • Provide touch stone and practical place of work for interaction with vendors • First major test bed in the form of a Dell / Mellanox / NVIDIA GPU cluster has been deployed in the lab last month and will be used by consortium to drive design R&D
SKA Exascale computing in the desert • The SKA SDP compute facility will be at the time of deployment one of the largest HPC systems in existence • Operational management of large HPC systems is challenging at the best of times - When HPC systems are housed in well established research centres with good IT logistics and experienced Linux HPC staff • The SKA SDP could be housed in a desert location with little surrounding IT infrastructure, with poor IT logistics and little prior HPC history at the site • Potential SKA SDP exascale systems are likely to consist of 100,000 nodes occupy 800 cabinets and consume 30 MW. This is very large – around 5 times the size of one today largest supercomputer –Titan Cray at Oakridge national labs. • The SKA SDP HPC operations will be very challenging
The challenge is tractable • Although the operational aspects of the SKA SDP exacscale facility are challenging they are tractable if dealt with systematically and in collaboration with the HPC community.
SKA HPC operations – functional elements • We can describe the operational aspects by functional element • Machine room requirements ** • SDP data connectivity requirements • SDP workflow requirements • System service level requirements • System management software requirements** • Commissioning & acceptance test procedures • System administration procedure • User access procedures • Security procedure • Maintenance & logistical procedures ** • Refresh procedure • System staffing & training procedures **
Machine room requirements • Machine room infrastructure for exascale HPC facilities is challenging • 800 racks, 1600M squared • 30MW IT load • ~40 Kw of heat per rack • Cooling efficiency and heat density management is vital • Machine infrastructure at this scale is both costly and time comsuming • The power cost alone at todays cost is £30M per year • Desert location presents particular problems for data centre • Hot ambient temperature - difficult for compressor less cooling • Lack of water - difficult for compressor less cooling • Very dry air - difficult for humidification • Remote location - difficult for DC maintenance
System management software • System management software is the vital element in HPC operations • System management software today does not scale to exascale • Worldwide coordinated effort to develop system management software for exascale • Elements of system management software stack:- • Power management • Network management • Storage management • Workflow management • OS • Runtime environment • Security management • System resilience • System monitoring • System data analytics • Development tool
Maintenance logistics • Current HPC technology MBTF for hardware and system software result in failure rates of ~ 2 nodes per week on a cluster a ~600 nodes. • It is expected that SKA exascale systems could contain ~100,000 nodes • Thus expected failure rates of 300 nodes per week could be realistic • During system commissioning this will be 3 or 4 X • Fixing nodes quickly is vital otherwise the system will soon degrade into a non functional state • The manual engineering processes for fault detection and diagnosis on 600 will not scale to 100,000 nodes. This needs to be automated by the system software layer • Vendor hardware replacement logistics need to cope with high turn around rates
Staffing levels and training • Providing functional staffing levels and experience at remote desert location will be challenging • Its hard enough finding good HPC staff to run small scale HPC systems in Cambridge – finding orders of magnitude more staff to run much more complicated systems in a remote desert location will be very Challenging • Operational procedures using a combination of remote system administration staff and DC smart hands will be needed. • HPC training programmes need to be implemented to skill up way in advance
Early Cambridge SKA solution - EDSAC 1 Maurice Wilkes