MW clients in CVMFS(ATLAS perspective)

Simone Campana (on behalf of many)

CERN IT-ES

Simone Campana – Nov 2012 GDB 2

• MW clients are installed in CVMFS– Each release on a dedicated path– With a setup.sh script on that path

• Sites can install clients locally or use CVMFS ones– The setup.sh script should overrule the existing configuration

• Panda will instruct the pilot about which setup to source– Global configuration, with the possibility to overwrite per queue and per

job

• This would allow flexibility in commissioning new clients and deploy rapidly bug fixes

Desired Scenario

Simone Campana – Nov 2012 GDB 3

• “MW Clients” on the WN means– The Data Management stuff– VOMS clients

• 32 vs 64 bits– The default should be using 64 bits– We need also 32 bits libraries (for Athena)– Having both in LD_LIBRARY_PATH should be enough

• Python version– Multiple python versions of clients should be in CVMFS (2.6,2.7 ..

will be reduced)– setup.sh should allow an argument to specify the python version to

use

Some More Details

4

• ATLAS installed MW clients in CVMFS (ATLAS RootBase)

• Stop-gap solution to simplify the EMI-2 testing– Build a tarball from RPMs

• http://walkerr.web.cern.ch/walkerr/emi_maketar.sh

– Unpack in CVMFS– Add the setup scripts for the environment

• Tried in UK, several iterations needed. Finally got to work– A thread of 53 emails, with 10 people

• Rod Waker (tarball builder)• Asoka Da Silva (installation and configuration in CVMFS)• A. DeSalvo (ATLAS Grid SW installation)• UK site managers (particularly Cambridge), Alessandra and Wahid

– And this to configure ATLAS only… Simone Campana – Nov 2012 GDB

What has been done

Simone Campana – Nov 2012 GDB 5

• This is not just about making a tarball with rpm2cpio– The configuration is the hard part– And whichever solution needs to be maintained

• We should discuss– If we need this– Who can participate to the effort and how

• ATLAS can offer some effort and an infrastructure for commissioning/testing– through Panda+HammerCloud

• ATLAS does not have the right expertise nor manpower for client release management and configuration– So can not commit to WLCG for maintaining MW clients in CVMFS

Conclusions