NPACI Panel on Clusters

1
NPACI Panel on Clusters

• David E. Culler
• Computer Science Division
• University of California, Berkeley
• http//www.cs.berkeley.edu/culler

2
Clusters have Happened

• IBM
• SGI
• SUN
• HP
• Microsoft
• ...

3
Performance Cost-Performance

• April 1998 T3E vs Intel Pentium II on NAS
  Benchmarks
• http//www.nersc.gov/research/FTG/pcp
• T3E-900 PII-400
• BT 63.5 62.2
• LU 70.2 73.6
• SP 44.7 45.5

4
Berkeley (NPACI) NOW

• 100 Sun Ultra2 workstations
• Inteligent network interface
• proc mem
• Myrinet Network
• 160 MB/s per link
• 300 ns per hop

http//now.cs.berkeley.edu
5
Beowolf Consortium

• LINUX PCs
• Fast ethernet
• Basic stand-alone and batch
• http//www.beowulf.org/consortium.html
• http//www.beowulf.org/
• http//ns.baltzer.nl/cluster/cluster.html
• http//www.cs.orst.edu/swarm/about.html
• cluster cookbook

6
HPVM (NPACE)

• NT PCs
• Myricom Network
• Fast Messages
• LSF start-up

http//www-csag.cs.uiuc.edu/projects/hpvm.html
7
Berkeley Millennium

• PC-based Unix and NT Clusters
• Departmental and Campus
• Shared as Computational Economy

http//www.millennium.berkeley.edu
8
What you get off the shelf

• Go to your favorite web site and order
• Dual PII 450 MHz, 1 GB Mem, 36 GB disk
• 9,563 at Dell
• 4400 CPU Hours per Quarter to your self!
• 1.20 CPU hours (at 30 over 3 years)
• Buy 5?

9
Three Kinds of Clusters

• Throughput Clusters
• Availability Clusters
• High-Performance Parallel Clusters

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Throughput Clusters

• Workstation / PC Farms
• Provide resource pool for large numbers of
  sequential jobs
• Used widely in industry
• toy story on 2000 sparcstations
• ultrasparc on 1000 sparcstations
• Can also include background on desktops
• CONDOR
• Application specific front-ends attractive
• parametric studies, monte carlo
• Fill cracks in parallel clusters
• Big farms require infrastructure

11
Availability Clusters

• Use system redundancy to mask faults
• all big databases do it
• VAX Clusters gt IBM sysplex gt Wolf Pack

12
High-Performance Clusters

• Utilize modern system area networks and
  user-level communication layers to construct
  general purpose parallel machine from commodity
  parts

13
Emerging System Area Networks

• Gigabit Ethernet
• price dropping, widely deployed
• System Area Networks
• Myricom
• ServerNet
• Synfinity
• Virtual Interface Architecture
• Intel/Microsoft/Compaq std based on univ.
  research prototypes

14
MPI Performance
15
Example NAS Parallel Benchmarks

• Better node performance than the Cray T3D
• Better scalability than the IBM SP-2

16
Cluster-Wide Parallel I/O

• Sustain 500 MB/s disk bandwidth and 1,000 MB/s
  network bandwidth by driving all the disks

17
Software Base is Growing

• Technical software moving to Linux and NT
• NAG, matlab, petc, ...
• Cluster prototypes being hardened and packaged
• Cookbooks emerging
• Few cluster-integrator companies

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Summary of the State of the Art

• Cluster designs are emerging in many areas
• throughput, availability, parallel computing
• technology is advancing
• Still immature software base
• strong ties to free software movement
• Many small clusters by spit and baling wire
• Large clusters require engineering
• commercial components improving
• Rapid pace of change presents sys. Admin
  challenge
• not unlike the desktop problem
• Management tools badly needed

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What Does it Mean for NPACI

• Where do clusters fit with computational science
  and engineering needs?
• Cycles vs Software vs Administration vs
  Expertise?
• What role should the center take?
• What role should partner sites have?