GridPP Testbed

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GridPP Testbed
The GridPP Testbed is currently distributed
across 17 High Energy Physics sites in the
UK. The fabric of the physical testbed is
configured to form several logical grids. The
bulk of the fabric is operated as part of the EU
DataGrid (EDG) Application Testbed.
May 2003
Security - The trust infrastructure is built on
digital certificates (eg UK eScience CA) and on
membership lists of Virtual Organisations,
published via LDAP. Local files listing
authorized certificate subject names are
constructed automatically. Attribute certificates
from VOMS servers are also available. Monitoring
- Globus MDS, and GridPP/EDGs R-GMA systems are
used for the monitoring of sites. So Grid
components can make decisions on behalf of the
user as to where best to send jobs or retrieve
copies of data, it is essential that a monitoring
infrastructure be in place, and the R-GMA
infrastructure is designed to be scalable,
flexible and efficient. Fabric Management -
Automated management of gatekeepers, fileserver
and worker nodes is provided by Edinburghs LCFG.
The fabric is also instrumented to publish its
state into the Monitoring system. Resource
Brokering - The Resource Broker uses published
information to match the requirements stated in
the job description file, which can include
sophisticated expressions involving requests for
optimal characteristics (the fastest site with a
copy of this data) This relieves the user from
having to know where data is stored and what the
minute-by-minute current status of each suitable
site is. Storage Management - Storage Element
fileserver provides homogenous Grid access to a
wide variety of bulk data storage systems,
including large disk arrays and tape vaults, but
also single disks on modest local servers. Data
Management - Local Replica Catalogs exist at each
storage resource, and multiple Replica Location
Services may aggregate this information. The
architecture is designed to be scalable and
efficient when deployed on real, production
Grids.