Grid Computing

1
Grid Computing

• AEI Numerical Relativity Group has access to
  high-end resources in over ten centers in
  Europe/USA
• They want
• Bigger simulations, more simulations and faster
  throughput
• Intuitive IO at local workstation
• No new systems/techniques to master!!
• How to make best use of these resources?
• Provide easier access noone can remember ten
  usernames, passwords, batch systems, file
  systems, great start!!!
• Combine resources for larger productions runs
  (more resolution badly needed!)
• Dynamic scenarios automatically use what is
  available
• Many other reasons for Grid Computing for
  computer scientists, funding agencies,
  supercomputer centers ...

2
Grand Picture
Viz of data from previous simulations in SF café
Remote steering and monitoring from airport
Remote Viz in St Louis
Remote Viz and steering from Berlin
DataGrid/DPSS Downsampling
IsoSurfaces
http
HDF5
T3E Garching
Origin NCSA
Globus
Simulations launched from Cactus Portal
Grid enabled Cactus runs on distributed machines
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Thorn HTTPD

• Thorn which allows simulation any to act as its
  own web server
• Connect to simulation from any browser anywhere
• Monitor run parameters, basic visualization, ...
• Change steerable parameters
• See running example at www.CactusCode.org
• Wireless remote viz, monitoring
  and steering

4
Users View
5
User Portal

• Find resources
• automatically finds machines with a user
  allocation (group aware!)
• continuously monitor resources, network etc.
• Authentification
• single login, dont need to remember lots of
  usernames/passwords
• Launch simulation
• automatically create executable on chosen machine
• write data to appropriate storage location
• negotiate local queue structures
• Monitor/steer simulations
• access remote visualization and steering while
  simulation is running
• collaborative choose who else can look in
  and/or steer
• performance how efficient is the simulation?
• Archiving
• store thorn lists, parameter files, output
  locations, configurations,

6
Cactus Portal

• KDI ASC Project
• Technology Globus, GSI, Java Beans, DHTML, Java
  CoG, MyProxy, GPDK, TomCat, Stronghold
• Allows submission of distributed runs
• Accesses the ASC Grid Testbed (SDSC, NCSA,
  Argonne, ZIB, AHPCC, WashU, AEI)
• Undergoing testing by users now!
• Main difficulty now is that it requires
  everything to work
• But is going to revolutionise our use of
  computing resources

7
ASC Astrophysics Simulation Collaboratory

• NSF Funded Knowledge and Distributed Intelligence
  project
• Institutes WashU, Rutgers, Argonne, U. Chicago,
  NCSA
• Aim Develop a collaboratory for the astrophysics
  community to provide the capability for massively
  parallel computation including AMR, interactive
  visualization and metacomputing.
• http//www.ASCPortal.org/
• ASC Portal General simulation portal interfacing
  to Cactus
• Globus, GSI, Java Beans, DHTML, Java CoG,
  MyProxy, GPDK, TomCat, Stronghold
• Version 1 included code assembly, compilation,
  job submission
• Version 2 now being developed, based on user
  feedback