Speaker
Mr
Lars Fischer
(Nordic Data Grid Facility)
Description
The Tier-1 facility operated by the Nordic DataGrid Facility (NDGF) differs
significantly from other Tier-1s in several aspects: It is not located one or a few
locations but instead distributed throughout the Nordic, it is not under the
governance of a single organization but instead a "virtual" Tier-1 build out of
resources under the control of a number of different national organizations.
We present the technical implications of these aspects as well as the high-level
design of this distributed Tier-1. The focus will be on computations, storage and
monitoring.
In order to look like a single site some services requires one single entry point.
Most notably is the srm entry point to storage. This is archived using dCache, but
with a number of additional features developed by NDGF and DESY/FermiLab.
Computations are controlled by the NorduGrid ARC middleware, which has proven to be a
reliable and easy to install a the sites and on top of that supports the distribution
of the compute elements very well. Integration happens at the HEP experiment level,
where one or more VO-boxes provide the interface between the experiments and the ARC
middleware.
Finally, diagnosing problems at sites where NDGF staff does not have administrative
access to the machines requires a well developed set of monitoring services. This
includes SAM tests especially tailored to the NDGF setup and use of other standard
monitoring software packages.
Authors
Dr
Josva Kleist
(Nordic Data Grid Facility)
Mr
Lars Fischer
(Nordic Data Grid Facility)
Dr
Michael Grønager
(Nordic Data Grid Facility)
Dr
Oxana Smirnova
(Nordic Data Grid Facility)
