Speaker
Caitriana Nicholson
(University of Glasgow)
Description
Simulations have been performed with the grid simulator OptorSim using the expected
analysis patterns from the LHC experiments and a realistic model of the LCG at LHC
startup, with thousands of user analysis jobs running at over a hundred grid sites.
It is shown, first, that dynamic data replication plays a significant role in the
overall analysis throughput in terms of optimising job throughput and reducing
network usage; second, that simple file deletion algorithms such as LRU and LFU
algorithms are as effective as economic models; third, that site policies which allow
all experiments to share resources in a global Grid is more effective in terms of
data access time and network usage; and lastly, that dynamic data management applied
to user data access patterns where particular files are accessed more often
(characterised by a Zipf power law function) lead to much improved performance
compared to sequential access.
Primary authors
Prof.
A. T. Doyle
(University of Glasgow)
Caitriana Nicholson
(University of Glasgow)
