AEI-Clustertag, 12.05.2004 GAVO and GridComputing

German Astrophysical Virtual Observatory

Gadget on GAVOGRID

AEI-Clustertag, 12.05.2004 GAVO and GridComputing

WebServices GridServices

GAVO Architecture

GAVO WebPortal

ConeSearch

Files DB

HTTP, SOAP

MatcherTemporaryDataSpace

UserSpace

Computing Tasks

Secure Protocols

Grid Enabled Sites

Normal security realm

Grid security realm

VO-Sites

AEI-Clustertag, 12.05.2004 GAVO and GridComputing

GAVO-Grid

GAVO-GRID (testbed) using Globus

AEI-Clustertag, 12.05.2004 GAVO and GridComputing

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 timestep80% calculation, 20% communication

AEI-Clustertag, 12.05.2004 GAVO and GridComputing

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

AEI-Clustertag, 12.05.2004 GAVO and GridComputing

GAVO-GRID

Results from tests with

-uniform nodes

Wall time

Comm time

On board 167,05 0,11Across site 179,69 1,05(np = 8) 105,3 1,30

AEI-Clustertag, 12.05.2004 GAVO and GridComputing

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

On site 4/4 AMD/XEON

85,9 0,15

Across site 4/4 AMD/XEON

105,33 1,18

Across site 8/8 AMD/XEON

77,63 1,96

AEI-Clustertag, 12.05.2004 GAVO and GridComputing

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 optionwhich can significantly lower the costs of getting biggersimulations running.

One of the main issues then is allocation of more bandwidth

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.

AEI-Clustertag, 12.05.2004 GAVO and GridComputing

GRID-Collaboration

AEI and AIP are using grid-technologydo demanding cosmological simulations

working towards a grid-integration of their respective clusters

working on specific problems (visualization of simulation results, distributed file systems)