1. ALICE FAIR Meeting
KVI, 2010
Kilian Schwarz
GSI

2. ALICE Analysis Facilities
is the time for medium sized analysis facilities eventually already over ? For publications people need to do analysis of large scale data sets with good statistics ...
contribution GSIAF
A. Manafov contributes to developing PoD for AliEn
GSIAF resources can be made available via PoD-Grid jobs
number of job slots will be in agreement with resources pledged to WLCG

3. user feedback ALICE GSI community
all in all users are happy :-)
most burning issues have been solved in AliEn v2-18
also AliEn plugin works
merging is still an issue, though. It runs on local machine and fails with too much output
things which could be improved
possibilities to delete data in AliEn and on SEs should be introduced
documentation on Web pages should be updated more frequently
access to OCDB database
reliability of central services
ML transfer request GUI could be made public

4. feedback CBM
central AliEn services at GSI, compiled for local environment, therefore:
generic build system which should be less SL dominated and should work also on other systems without the need to fix problems continuously
why are packages which are available on the local system, not taken from there ? Instead most packages are shipped with AliEn ...
e.g. ssl, ...
advantages:
build system becomes more slim
no old software packages
no missing security updates
not that many users so far

5. AliEn – Oracle interface
needed especially by CBM, since GSI maintains a central Oracle DB which should be used to achieve synergy effects
being developed by Almudena Montiel Gonzalez, GSI
thanks to Pablo Saiz (CERN) and Michael Dahlinger (GSI) for continuous support

6. Current status AliEn interface for Oracle
04/30/10
Current status AliEn interface for Oracle
Interface to the database through the module Database.pm. Implements DBI (Database independent interface for Perl)
Same interface for several drivers
To make this possible we need to use standard SQL , so that all the drivers “understand” the SQL statements
BUT by using the specific SQL from each driver we optimize the use of that driver.
So we need a generic interface, but without sacrificing the performance. 6 6

7. Current status Alien interface for Oracle
04/30/10
Current status Alien interface for Oracle
Abstract class Database, subclasses implemented for Mysql or Oracle according to the driver.
We indicate the driver in LDAP, as well as the database, host and port, for example
Mysql:
hostname:port/mysql/databasename
Oracle:
hostname:port/Oracle/databasename:
schemaname
We need privileged access to the database when creating the bootstrap database for AliEn. 7 7

8. Current status Alien interface for Oracle
04/30/10
Current status Alien interface for Oracle
Changes implied for the code in AliEn application:
Translate SQL into portable SQL, taking into account data manipulation, data definition and administrative statements.
create statements are different, names can be reserved words in Oracle (type, time)
Data storage: (MySQL: databases, Oracle: schemas)
Authentication and privileges: (MySQL: database level, Oracle: object level) 8 8 8

9. Current status Alien interface for Oracle
04/30/10
Current status Alien interface for Oracle
Done:
Translated SQL into “portable” SQL for all the modules related to the File Catalog and the Database:
/Database.pm
/Database/mysql.pm
/Database/Oracle.pm /Database/Catalogue.pm
/Database/Catalogue/Shared.pm
/Database/Catalogue/LFN.pm
/Database/Catalogue/GUID.pm
/Catalogue.pm
/Catalogue/Admin.pm
/Catalogue/Basic.pm
..etc
The bootstrap database can be created in Oracle.
Doing research on the way to implement the Authentication trough Digital Certificates in Oracle.
To be done:
Run the main services with Oracle as driver for the File Catalogue
Translate into “portable” SQL the rest of the modules. 9 9

10. Feedback PANDA tools for data deletion and SE cleanup are missing
wrote our own little scripts to cleanup Ses
bin/view/Computing/CleanSE
installation for LCG type sites not sufficiently documented.
Panda started own documentationhttp://panda- wiki.gsi.de/cgi-bin/viewauth/Computing/LCGSiteSetUpLog
alien-auto-install has been replaced but nobody informed PANDA
modern GUI via which one should be able to
define a project, start jobs, see what jobs run where, copy produced data to local disk, delete projects
ML production manager goes in that direction
most information is actually existing but in too many distributed views
problems encountered in last DC (AliEn v2-17)
if too many jobs try to save in a badly configured SE, many hanging jobs in status SAVING. In the end no new jobs can be inserted anymore.
jobOptimiser had to be restarted several times
site services needed to be restarted to be able to accept jobs again

11. AliEn AliEn interface
being implemented by Szymon Daraszewicz, University College London and GSI
thanks for continuous support by Pablo Saiz
main features:
job can be submitted from VO1 to an interface CE in VO1
interface CE starts JobAgent of VO1 in VO2
job gets assigned to that JobAgent
various open issues:
job does not start yet
kill subroutine in Alien.pm has to be rewritten
getQueueStatus in Alien.pm has to be rewritten

12. AliEn AliEn interface – idea outline
[VO1] submit jdl with Requirements=other.CE=”vo1::to::vo2
This calls submit routine in Alien.pm submitting a different jdl
Changing the environment from vo1 to vo2 in Alien.pm
$ENV{ALIEN_LDAP_DN}="denbp052v001:8389/o=szymon_vo2,dc=gsi,dc=de";
my $jdl="executable=\"runOtherVOJobAgent\";
arguments=\"$env\";
requirements=other.CE==\"usr_vo2::GSI::vo2_ce1\"";
The job “runOtherVOJobAgent” shows up in vo2
following the vo2 numbering convention.
It terminates properly
with output being written to file in vo2.
Contents of runOtherVOJobAgent:
sets the environment variables to VO1
export ALIEN_CM_AS_LDAP_PROXY=denbp052v002.gsi.de :8393
export ALIEN_LDAP_DN=”denbp052v002:8389/o=szymon_vo1,dc=gsi,dc=de”
export ALIEN_ORGANISATION=szymon_vo1
export HOSTNAME=denbp052v002.gsi.de
Starts AliEn RunAgent
Unsets the environment variables (back to vo2)

13. AliEn AliEn interface – current job life-cycle
[VO1] submit jdl with Requirements=other.CE=”vo1::to::vo2
Jobs inserted in both vos
The jobAgent in VO2 times out and,
so that the job in VO2 FINISHES;
the status of VO1 stays as ASSIGNED
[VO1] WAITING usr_vo1/bin/run001
[VO2] WAITING usr_vo2/bin/runOtherVOJobAgent
[VO2] ASSIGNED usr_vo2/bin/runOtherVOJobAgent
[VO2] RUNNING usr_vo2/bin/runOtherVOJobAgent
[VO1] ASSIGNED usr_vo1/bin/run001