Slides - Indico

Basic aliensh
S. Bagnasco, INFN Torino
CNAF Nov 27-28, 2007
Preparing the certificates
Certificates should be stored
under $HOME/.globus
Globus enforces privacy on your private key!
(chmod 400)
Stefano Bagnasco - INFN Torino
INFN Grid School for Users - CNAF Nov 27-28, 2007 - 2 /3475
Changes in environment
Stefano Bagnasco - INFN Torino
INFN Grid School for Users - CNAF Nov 27-28, 2007 - 3 /3475
Getting a GRID proxy
Authentication command
(default is the local username)
Happens every 24 hours
Put certificate password
Stefano Bagnasco - INFN Torino
INFN Grid School for Users - CNAF Nov 27-28, 2007 - 4 /3475
Getting an AliEn token
Stefano Bagnasco - INFN Torino
INFN Grid School for Users - CNAF Nov 27-28, 2007 - 5 /3475
Authentication problems I

Globus related:

Permissions on $HOME/.globus/userkey.pem are not
private to the user
•

chmod 400 userkey.pem
Your certificate authority is exotic and not known to the
server.

Your certificate has expired.

Clock skew:
•
•
Your local computer time is in the future with respect to the server's time.
Your local computer time is more in the past than the certificate life time.
Stefano Bagnasco - INFN Torino
INFN Grid School for Users - CNAF Nov 27-28, 2007 - 6 /3475
Authentication problems II

alien-token-init related:



You have not gone through all 5 steps of the AliEn user
registration.
You have not given the AliEn user name as an argument to
the token-init command and your local user name is not
identical to the AliEn user name.
The script wants to bootstrap the installation but you don’t
have write permissions on the installation path
•

Avoid bootstrapping by setting the GSHELL_ROOT environment variable.
API servers are not working…
Stefano Bagnasco - INFN Torino
INFN Grid School for Users - CNAF Nov 27-28, 2007 - 7 /3475
Try it out!

Upload your certificates to your machines:



Store them under e.g: /afs/cern.ch/user/t/trn2301/.globus/
Check that the key file is read only.
Get a valid alien token.

If asked if you want to compile the gapi and xrootd libs answer YES
(everything is already precompiled)
Stefano Bagnasco - INFN Torino
INFN Grid School for Users - CNAF Nov 27-28, 2007 - 8 /3475
Accessing the shell
Message of the day.
Standard bash shell with grid comands
Main bash features are available.
Not all shell helper programs are available.
Some local commands (like ls, cat etc) are overwritten
with the corresponding GRID commands.
File/path tab completion in the virtual GRID directory.
Stefano Bagnasco - INFN Torino
INFN Grid School for Users - CNAF Nov 27-28, 2007 - 9 /3475
Shell Basic commands I
Tab completion working!!!
Stefano Bagnasco - INFN Torino
INFN Grid School for Users - CNAF Nov 27-28, 2007 - 10 /3475
Shell Basic commands II
Stefano Bagnasco - INFN Torino
INFN Grid School for Users - CNAF Nov 27-28, 2007 - 11 /3475
Shell Basic commands III
Stefano Bagnasco - INFN Torino
INFN Grid School for Users - CNAF Nov 27-28, 2007 - 12 /3475
whereis command
Stefano Bagnasco - INFN Torino
INFN Grid School for Users - CNAF Nov 27-28, 2007 - 13 /3475
Viewing files I
Stefano Bagnasco - INFN Torino
INFN Grid School for Users - CNAF Nov 27-28, 2007 - 14 /3475
viewing files II
Stefano Bagnasco - INFN Torino
INFN Grid School for Users - CNAF Nov 27-28, 2007 - 15 /3475
Editing files
Define your preferred editor via the variable EDITOR:
'emacs'
'emacs -nw'
'xemacs'
'xemacs -nw'
'pico'
'vi' (DEFAULT)
'vim'
The file is temporary in /tmp on your local disk and then is
uploaded once you exit the editor!
Stefano Bagnasco - INFN Torino
INFN Grid School for Users - CNAF Nov 27-28, 2007 - 16 /3475
Clean up old versions
Stefano Bagnasco - INFN Torino
INFN Grid School for Users - CNAF Nov 27-28, 2007 - 17 /3475
Copying out files
GOLDEN RULE
If you want to access your local directory structure while you
are in the shell you should start by having the prefix “file:”
e.g: cp file:/home/pchrist/gshell.sh gshell.sh
Stefano Bagnasco - INFN Torino
INFN Grid School for Users - CNAF Nov 27-28, 2007 - 18 /3475
File catalogue structure

The path name will be:



for ‘real’ data: /data/<Year>/<AcceleratorPeriod>/<RunNumber>/
for simulated data: /sim/<Year>/<ProductionType>/<RunNumber>/
Subdirectories will be called:





Raw/
cond/
reco/<PassX>/ESD/
reco/<PassX>/AOD/
…

File names will look like this: <xxxx>.AliESD.root

For further information see:


http://indico.cern.ch/conferenceDisplay.py?confId=3280
http://cern.ch/Oldenburg/MetaData/MetaData.doc
Stefano Bagnasco - INFN Torino
INFN Grid School for Users - CNAF Nov 27-28, 2007 - 19 /3475
Querying the File Catalogue
aliensh:[alice] [1] find -x pp
/alice/cern.ch/user/p/pchrist/Tutorial/PDC06/*
*Merged*tag.root > pp.xml
Redirect the output to
the xml collection.
Stefano Bagnasco - INFN Torino
INFN Grid School for Users - CNAF Nov 27-28, 2007 - 20 /3475
Querying the File catalogue
aliensh:[alice] [1] find -x pp
/alice/data/2008/LHC08a/*/reco/Pass3/*
*Merged*tag.root
Run:collision_system=”pp” and
Run:stop<"2008-03-20 10:20:33" and
Run:start>"2008-03-19" > pp.xml
Stefano Bagnasco - INFN Torino
INFN Grid School for Users - CNAF Nov 27-28, 2007 - 21 /3475
Try it out I



Access the alien shell and try some simple
commands:

Check your user name by typing ‘whoami’.

List the contents of your home directory.

Print the working directory.
Create the following directory structure in your AliEn
space:

$HOME/bin (if it is not there)

$HOME/GridSchool
Get the information of the file with ‘whereis’:
/alice/cern.ch/user/s/sbagnasc/GridSchool/GridSchoolNov2007.tgz
Stefano Bagnasco - INFN Torino
INFN Grid School for Users - CNAF Nov 27-28, 2007 - 22 /3475
Try it out II

Copy the AliEn file /alice/cern.ch/user/s/sbagnasc/GridSchool/GridTutorialNovember2007.tgz to your local $HOME/GridSchool

Exit the shell and unpack the file locally by typing: tar xvzf
GridSchoolNov2007.tgz

Enter again the shell and register:


The .csh files in your AliEn $HOME/bin

The .jdl files in your AliEn $HOME/GridSchool
Try the -v option!
Stefano Bagnasco - INFN Torino
INFN Grid School for Users - CNAF Nov 27-28, 2007 - 23 /3475
Try it out iII


Play with the ‘find’ command:
Access the shell again and query the f.c. and get all the tag
files (*.tag.root) under:
/alice/sim/2007/LHC07c/pp_minbias/8268/*

Get the output on your terminal (find /alice/…)

Get the output on your terminal in a xml format (find -x tag /alice/…)


Redirect the results to the tag.xml collection: the output will not be stored in
your AliEn working directory but rather in your local working directory.
Repeat the previous exercise limiting the number of output
files to 5 (find -l 5 ...).
Stefano Bagnasco - INFN Torino
INFN Grid School for Users - CNAF Nov 27-28, 2007 - 24 /3475
Tomorrow

Whatever is left over from today…

Write a JDL to generate some file
Submit the job and check its progress
Check the job’s output
Write a JDL to look at the output
Submit it to run wherever the file is
Get the result






If there is some time left, do the same actually
generating MC events and reconstructing them, or
even analyzing some PDC data…
Stefano Bagnasco - INFN Torino
INFN Grid School for Users - CNAF Nov 27-28, 2007 - 25 /3475