CMS Remote Analysis Builder 2 - CRAB2
Introduction
CRAB is a utility to submit CMSSW jobs to distributed computing resources. By using CRAB you will be able to:
- Access CMS data and Monte-Carlo which are distributed to CMS aligned centres worldwide.
- Exploit the CPU and storage resources at CMS aligned centres.
Before starting to learn about CRAB, you may want to get an overview of the Grid model and of a typical analysis workflow. For that purpose read the following chapters of the
CMS Offline WorkBook:
For detailed documentation about CRAB, see section
Advanced CRAB Documentation further down in this page.
CRAB Client and Server
AS OF AUGUST 2013, CRAB2 SERVER HAS BEEN TURNED OFF, RECOMMENDED SCHEDULER IS REMOTEGLIDEIN.
Getting Started
This section describes how to begin using CRAB to perform your analysis on the Grid.
Prerequisites
To use CRAB to submit your CMSSW job to the Grid you must meet some prerequisites, which you can find in the
CRAB Prerequisites page. There you will also find information on how to setup your environment to use CRAB at CERN and how to do a private installation of CRAB.
Basic Workflows
You can find a guide to the basic functionality of CRAB in the
CRAB Basic Workflows page. If you have never used CRAB before, it is a good place to learn how to use the tool.
Latest Tutorial
Regular tutorials are given on using CRAB. The course material for these tutorials is stored online for future reference, although it refers to specific CRAB and CMSSW versions that may no longer be available.
Advanced CRAB Documentation
The advanced user should refer to the following specific documentation as appropriate.
CRAB Online Manual
The
CRAB Online Manual
provides detailed documentation about CRAB commands and configuration parameters. This is the same documentation you get from the
crab -help
command.
LPC CAF at FNAL is a local analysis facility only accessible to users with a local
account. Like for CERN CAF, data there are not accessible to grid jobs.
To use CRAB on the FNAL LPC CAF, you need to do roughly as you do at CERN:
1) Setup CMSSW
2) Setup CRAB
For SL5 (cmslpc-sl5):
cmsrel CMSSW_X_Y_Z (only first time)
cd CMSSW_X_Y_Z
cmsenv
source /cvmfs/cms.cern.ch/crab/crab.(c)sh
If you want to use CRAB to submit to the local condor batch system, please see the additional instructions at
CRABonLPCCAF. If you created a .no_glite_setup file during the CRAB 26x/27x transition, you can safely delete that file now as it is no longer used.
Setup on other places
Please be aware that CRAB needs gLite_3_2 on sl5 and gLite_3_1 on SL4 (i.e. works with the official gLite UI version for the two operating systems).
FAQ, Troubleshooting, Getting Support
Diagnosing Problems
If a problem is encountered with CRAB you can begin with the following template. This template will help you to identify the nature of the problem and if a solution already exists:
Before contacting the CRAB feedback hypernews, you should consult the
Frequently Asked Questions (FAQ) page.
Getting Support
If you have still not found the solution to your problem, you may wish to consult the CRAB feedback hypernews forum.
If you are running locally in LPC, in case of problems please contact:
lpc-howto@fnalNOSPAMPLEASE.gov
When contacting crabFeedback, you must
- write brief description of the problem and of relevant error messages
- upload all files needed for debug. There is a crab option that provides the upload of your logs:
- if the problem affects some or all jobs, pick one with the issue (jobid) and do
- if jobs are in "done" status:
crab -getoutput <jobid>
so the stdout and fjr will be retrieved, then crab -uploadLog <jobid>
to upload all the necessary files
- if your jobs are aborted:
crab -postMortem <jobid>
so the postMortem file will be generated crab -uploadLog <jobid>
to upload all the files
- report the URL provided by the
crab -uploadLog
command in the email for the support.
- note: of course if your crab working directory is not the default
<username>_0_...
you need to add the -c option like for any other crab command
Useful Links
- CRAB Related
- Certificate Related
- Data Discovery
- Monitoring
- Sites
- Services
- CMSSW
- General
- Editing the twiki
CRAB Releases Notes
- CRAB client - standalone
- currently recommended version of the CRAB client, i.e. the one which is default on lxplus, is available at CRAB_current.tgz
. Release notes here
.
- Older CRAB versions here
- Even older CRAB versions here
CRAB references
CRAB presentations, posters, publications and tutorials page
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AndresTanasijczuk - 07 Oct 2014