Reference: Computing and Storage Attribute Queries (lcg-info)

Last modified: Wed Sep 12 18:11:11 BST 2007
Nick West
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For an introduction, see Interrogating the GRID

The lcg-infosites locates resources but to make more detailed queries, for example finding out what version of our software is installed you need logon to a user interface and use the lcg-info command.

The syntax is:-

lcg-info [--list-ce | --list-se] [--bdii bdii] [--vo vo] [--query <some_query>] [--attrs <some_attrs>]
  where
    --list-ce  query a CE (Computing Element)
    --list-se  query a SE (Storage Element)

    --query <some_query> Query to apply e.g. --query 'TotalCPUs>=10'
    --attrs <some_attrs> Attributes to list e.g. --attrs 'RunningJobs'
To see what attributes are available:-
lcg-info --list-attrs
which produces output like this:-
Attribute name  Glue object class     Glue attribute name

EstRespTime     GlueCE                GlueCEStateEstimatedResponseTime
WorstRespTime   GlueCE                GlueCEStateWorstResponseTime
TotalJobs       GlueCE                GlueCEStateTotalJobs
TotalCPUs       GlueCE                GlueCEInfoTotalCPUs
Use the "Attribute name" in queries and attributes.

A query expression is formed by using the operators =, <, <=, > and >= to compare an attribute to a value.

When checking on string values * is a wildcard e.g.

 --query 'OS=SL*'
Query expressions can be ANDed (but not ORed) by combining using a comma e.g.
--query 'TotalCPUs>10,OS=SL*,FreeCPUs>5'

To list more than one attribute form a comma separated list e.g.

--attrs 'RunningJobs,FreeCPUs'
For example for MINOS:-
lcg-info --list-ce --vo minos.vo.gridpp.ac.uk --query 'CE=*.rl.ac.uk*' --attrs EstRespTime,TotalCPUs,Memory,ClockSpeed
To see how heavily loaded a site is, for example the RAL Tier 2, omit the --vo option to see all VOs:-
lcg-info --list-ce  --query 'CE=heplnx206.pp.rl.ac.uk*' --attrs TotalJobs,WaitingJobs,RunningJobs

For more information see

lcg-info --help
  (press q to quit)
and @ LCG-2 User Guide: lcg-info
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