Last update:
Apr 1, 2000
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Building a large location table to find replicas of physics objects
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Koen Holtman,
Heinz Stockinger
CERN
Speaker:
Koen Holtman
The problem of building a large location table for physics objects
occurs within a number of planned physics data management systems,
like those that control reclustering and wide-area replication. To
satisfy their efficiency goals, these systems have to make local or
remote replicas of individual physics objects, which contain raw or
reconstructed data for a single event, rather than replicas of large
run or ntuple files. This replication implies the use of a table to
resolve the logical, location independent object descriptor into a
physical location where an object replica can be found. For modern
physics experiments the table needs to scale to at least some 10**10
objects. We argue that such a table can be efficiently implemented by
limiting the freedom of lookup operations, and by exploiting some
specific properties of the physics data model. One specific viable
implementation is discussed in detail, and the results of performance
tests are shown.
Presentation: | Short Paper: |
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