Atlas Metadata Interface
James Walder
Lancaster University
http://ami.in2p3.fr/
AMI
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http://ami.in2p3.fr/
The Atlas Metadata Interface
Used for ‘dataset discovery’:
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Necessary for Monte Carlo searches,
It is faster than RQT, if you know what you are after;
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Doesn’t perform explicit data quality or conditions queries
Dataset are also produced with specific Athena releases, geometry tags,
conditions tags. These are coded into special config tags that appear in the
dataset name.
data09_900GeV.00142406.physics_L1CaloEM.merge.DESD_COLLCAND.r988_p62/
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Eg: r988_p62 means reconstructed under tag r988 from which a DPD was
made using tag p62
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AMI also contains the tag nomenclature ( r, p, e,s,f,m... )
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And the exact meaning of each individual tag definition: e.g. r988.
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James Walder
Data processing chain
Reconstruction
Detector & trigger
Digits
ESD
Digits
Monte Carlo
James Catmore
Physics analysis
AOD & TAG building
ESD
AOD
TAG
dAOD/dESD building
ATLAS offline software tutorial, CERN, 21st - 23rd October 2009
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Physics analysis
James Walder
Data Formats
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RAW -> Originates from the detector. Large, specialised usage.
ESD -> Still large -> used for performance and detector studies.
DESD; As ESD, but skimmed in some way; performance studies
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DESDM: As DESD, but includes trimming / thinning / slimming
AOD; For use with analysis. ESD format important for first data.
DPD; Derived Physics Data.
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Number of varieties exist. some are in pool.root Athena format
Names and definitions recently changed.
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DAOD: As AOD but skimmed according to some algorithm
DAODM: As DAOD, with additional trimming / thinning / slimming
DAODM2: new name for D2DPD. pool.root format data made by groups
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Others; the D3PDs are ROOT-ntuples produced by individual groups for common analysis within the
group.
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All will exist on the Grid;
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RAW and ESD will in general not be easily accessible.
Useful formats for first data:
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DESD_COLLCAND. As ESD, but only events that satisfy collision timing cuts.
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To be phased out.
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James Walder
Anatomy of a dataset name
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Dataset names hold much of the immediately useful metadata within it’s own
name.
Project name: data / mc 08/09...
energy: 900,GeV 2TeV
Type: physics,
calibration
File Type: RAW, ESD, DESD, AOD,DAOD
Stream
data09_900GeV.00142406.physics_L1CaloEM.merge.DESD_COLLCAND.r988_p62/
Run number or MC
dataset number
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File status: merged / recon
Production/
reconstruction tags:
Quickest way to find your data is through AMI, using specific parts of the
dataset name, and wildcards.
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(Container)
James Walder
AMI – Search examples
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https://ami.in2p3.fr
AMI Dataset Search
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Dataset search through wildcarded name search, or through use of keywords.
Also will translate the meaning of the reconstruction/production tags.
Use % as wildcard.
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eg: mc08%AOD%
data09%Min%AOD%r988%
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James Walder
AMI: tag interpretation
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Need to know the meaning behind the production tags?
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Key information: Geometry, Athena Releases, Conditions tags
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James Walder
Advanced Search
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Advanced search is a more ‘intelligent’ method of searching for specific sets
of data.
AMI
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James Walder
Tasks in this session
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Find the datasets you are interested in, and investigate their metadata
For this tutorial choose AOD format from the Minbias stream
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Try and find its provenance, locations where it is stored in the world, and the
number of events it contains.
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What (minimum) Athena release is needed to read it?
Look for similar datasets:
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of the same stream (e.g. the same dataset name, but with a different set of tags).
of the same set of config tags (eg the r988_p62).
What are the reasons for the differences?
Find out what information the config tags (eg. r988) hold and what they mean?
How many types of config tags are there - do you know what they all stand for?
Some Monte Carlo data has been recently produced, it can be found with
mc09_900%minbias%AOD%
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Try to understand the tags that are provided here and the
provenance related to MC.
Further details on how to use AMI are at the tutorial page:
http://ami.in2p3.fr/opencms/opencms/AMI/www/Tutorial/FastTrackTutorial.html
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James Walder