German Astrophysical Virtual Observatory Gadget on GAVOGRID AEI-Clustertag, 12.05.2004 GAVO and GridComputing

GAVO Architecture VO-Sites Grid Enabled Sites GAVO WebPortal HTTP, SOAP Secure Protocols WebServices GridServices Temporary DataSpace UserSpace ConeSearch Matcher Abstract View of current architecture: GAVO uses two tiers of services: Access to ConesSearch, Matcher through http and soap-protocols, the services are running within the normal levels of security (provided through the firewalls of the sites, allowing acccess to dedicated machines on known ports The Cone-Search queries archives in local databases and files and VO-archives through http and soap-protocols 2. Access to Grid-managed ressources: The matcher-engine validates itself to the Grid, to get access to computing facilities for parallel-processing and temporary storage Users, who obtained Login, get access to Grid-managed ressources (parallel-computing jobs, runtime information, job-results) Stores virtual data from matcher results or cone-searches in userspace Files DB Computing Tasks Grid security realm Normal security realm AEI-Clustertag, 12.05.2004 GAVO and GridComputing

GAVO-GRID (testbed) using Globus GAVO-Grid AEI-Clustertag, 12.05.2004 GAVO and GridComputing

running MPI-application across site-boundaries: GAVO-GRID Testcase for GAVO: running MPI-application across site-boundaries: Gadget is a widely used particle-code for cosmological simulations Gadget (MPI-version) requires 2n processors Gadget roughly uses for each timestep 80% calculation, 20% communication (GAlaxies with Dark matter and Gas intEracT ) AEI-Clustertag, 12.05.2004 GAVO and GridComputing

Running MPI-applications with Globus / mpichG2 GAVO-GRID Running MPI-applications with Globus / mpichG2 - all nodes communicate with each other (ip-adresses known) - using ssh instead of rsh - requires a range of TCP/IP-ports open (globus-tcp-range) - allocation of bandwidth (GAlaxies with Dark matter and Gas intEracT ) AEI-Clustertag, 12.05.2004 GAVO and GridComputing

Results from tests with uniform nodes 167,05 0,11 GAVO-GRID Results from tests with uniform nodes Wall time Comm time On board 167,05 0,11 Across site 179,69 1,05 (np = 8) 105,3 1,30 (GAlaxies with Dark matter and Gas intEracT ) AEI-Clustertag, 12.05.2004 GAVO and GridComputing

Results from tests with heterogenous nodes 162,03 0,11 GAVO-GRID Results from tests with heterogenous nodes Np Wall time Comm time On site 2/2 AMD/ XEON 162,03 0,11 Across site 4 AMD 97,7 1,16 4/4 AMD/ XEON 85,9 0,15 105,33 1,18 8/8 AMD/ 77,63 1,96 (GAlaxies with Dark matter and Gas intEracT ) AEI-Clustertag, 12.05.2004 GAVO and GridComputing

(GAlaxies with Dark matter and Gas intEracT ) GRID-Collaboration Simulations for cosmological problems improve with the number of particles. There is a clear relation between available computing ressources and the number of particles a simulation can handle. Integration of clusters using grid-technology is an option which can significantly lower the costs of getting bigger simulations running. One of the main issues then is allocation of more bandwidth (GAlaxies with Dark matter and Gas intEracT ) AEI-Clustertag, 12.05.2004 GAVO and GridComputing

GRID-Collaboration in Potsdam: Potsdam has a good net infrastructure, where more bandwidth is relatively easy available For testing purposes, a low cost solution providing more bandwith could be installed, including AEI, AIP, PIK, Uni Potsdam This could be a first step of building part of the D-Grid at Potsdam. (GAlaxies with Dark matter and Gas intEracT ) AEI-Clustertag, 12.05.2004 GAVO and GridComputing

are using grid-technology do demanding cosmological simulations GRID-Collaboration AEI and AIP are using grid-technology do demanding cosmological simulations working towards a grid-integration of their respective clusters working on specific problems (visualization of simulation results, distributed file systems) (GAlaxies with Dark matter and Gas intEracT ) AEI-Clustertag, 12.05.2004 GAVO and GridComputing