Using ganga with version 14 at Liverpool

What's different from before?

The main issue with using ganga with recent athena releases (14.x.y) is that athena uses a version of python (2.5) that is incompatible with gLite and SL4. This page shows one consistent way of using ganga with athena at Liverpool, based mainly on this TWiki page and various HyperNews discussions. There will be other ways to produce similar effects, this is simply one way that works.

These instructions are still based on ganga 4.4.15. When ganga version 5 is installed at Liverpool, these will be updated.

Step 1: Get a grid certificate

This is documented elsewhere

Step 2: Edit ~/.gangarc

Some changes are needed to the default .gangarc file to get EDG and gLite commands to work properly. If you don't already have a .gangarc file, you need to do Step 3, then run ganga -g from the command line to create one.

Within .gangarc, you need to make the following changes: Under [LCG]:

EDG_ENABLE = True
EDG_SETUP = /batchsoft/atlas/grid/ganga/LivConfig/grid-env.sh
GLITE_ENABLE = True
GLITE_SETUP = /batchsoft/atlas/grid/ganga/LivConfig/grid-env.sh
VirtualOrganisation = atlas

[LCG_Properties]

middleware = GLITE

Under [GridProxy_Properties] (called [defaults_GridProxy] in ganga 5.0.0):

voms = atlas

You need to do the above lines anyway to use this method, even if you've already used ganga before at Liverpool. If on the other hand you haven't (ie you ran ganga -g just now), you'll also need to add the lines below. Most can be edited and uncommented if you prefer. And of course, change the lines containing "flowerdew" as approprate for your own preferred setup.

Section	New line
[Configuration]	RUNTIME_PATH = GangaAtlas
[DefaultJobRepository]	local_root = /hepstore/store1/flowerdew/gangadir/repository
[FileWorkspace]	topdir = /hepstore/store1/flowerdew/gangadir/workspace
[LCG]	VirtualOrganisation = atlas
[LCG] or [LCG_Properties]	DefaultSE  = srm-atlas.cern.ch

Now on to step 3...

Step 3: Setup DQ2 and ganga

Unlike most grid sessions, it is generally recommended to do as little grid/athena setup as possible before starting ganga. I find these two lines sufficient:

source /batchsoft/atlas/grid/dq2/setup.sh
source /user1/flowerdew/bin/setup-atlas.sh

The DQ2 command sets up various "=dq2-=" client commands that you just don't get any other way. Note: I have been informed that the old "=dq2_=" commands are depricated - I have found at least one that doesn't work as expected any more.

The second command is a script that I have unashamedly nicked from the recommended lxplus setup, and I have hacked it to work at Liverpool. This should get moved to a more central location once Carl returns.

Step 4: Go to MyPackage/cmt/ and start ganga

Note this must be cmt/, not run/. For example:

cd testarea/14.1.0/groups/Liverpool/LiverpoolZBosonAnalysis/cmt
ganga

You will be prompted for your grid pass phrase here.

Step 5: Execute the three "magic" commands

These set up athena within ganga. Obviously, change the version to match what you want to do:

config['Logging']['Ganga']='INFO'
cmtsetup 14.1.0,32
setup

The ,32 in the cmtsetup command tells a 64 bit machine to use 32 bit binaries, as many grid machines are apparently still 32 bit.

Step 6: Continue as before

You now (hopefully) have everything set up OK, time to submit a job:

execfile('../share/MyFavouriteJobSubmissionScript.py') ### Or, copy the script into cmt/ first

-- MikeFlowerdew - 23 Jun 2008