1. Gridifying the LHCb Monte Carlo simulation system
Eric van Herwijnen, Joel Closier
Friday, 1 march 2002
WP8 Demo for DataGrid Review

2. Contents LHCb distributed computing environment
Demonstration of DataGrid middleware
Authentication
Job submission to DataGrid
Monitoring and control
Data replication
Resource scheduling – use of CERN MSS

3. LHCb LHC collider experiment 109 events * 1Mb = 1 Pb
We have a distributed computing model
Need to create, distribute and keep track of data automatically
We need the Grid to handle our distributed computing environment

4. Submit jobs
remotely
viaWeb
Update bookkeeping
database
Transfer data to
Mass store
Execute
on farm
Data Quality
Check

5. 1. Authentication
grid-proxy-init

6. 2. Job submission
dg-job-submit /home/evh/sicb/sicb/bbincl jdl -o /home/evh/logsub
bbincl jdl: #
Executable = "script_prod";
Arguments = " ,v235r4dst,v233r2";
StdOutput = "file output";
StdError = "file err";
InputSandbox = {"/home/evhtbed/scripts/x509up_u149","/home/evhtbed/sicb/mcsend","/home/evhtbed/sicb/fsize","/home/evhtbed/sicb/cdispose.class","/home/evhtbed/v235r4dst.tar.gz","/home/evhtbed/sicb/sicb/bbincl sh","/home/evhtbed/script_prod","/home/evhtbed/sicb/sicb dat","/home/evhtbed/sicb/sicb dat","/home/evhtbed/sicb/sicb dat","/home/evhtbed/v233r2.tar.gz"};
OutputSandbox = {"job txt","D ","file output","file err","job txt","job txt"};

7. 3. Monitoring and control

8. 3. Monitoring and control
dg-job-status
dg-job-cancel
dg-job-get-output

9. CERN testbed
Compute Element
Storage Element
data
Local disk
Job
globus-url-copy
data
register-local-file
publish
replica
catalog (Nikhef)
replica-get
Rest-of-Grid
Job
data
Storage Element

10. 4. Publish data on storage element
Copy data file to storage element:
globus-url-copy file:///${chemin}/L69999
gsiftp://lxshare0219.cern.ch/flatfiles/SE1/lhcb/L69999
Register stored data in the catalog:
/opt/globus/bin/globus-job-run lxshare0219.cern.ch /bin/bash -c "export
GDMP_CONFIG_FILE=/opt/edg/lhcb/etc/gdmp.conf;/opt/edg/bin/gdmp_register_local_file -d /flatfiles/SE1/lhcb"
Publish catalog:
/opt/globus/bin/globus-job-run lxshare0219.cern.ch /bin/bash -c "export GDMP_CONFIG_FILE=/opt/edg/lhcb/etc/gdmp.conf; /opt/edg/bin/gdmp_publish_catalogue -n"

11. 5. Resource scheduling – use of CERN MSS
Copy output to MSS:
rfcp L /castor/cern.ch/lhcb/mc/L
JDL to specify use of CERN MSS:
Executable = "script_prod";
Arguments = " ,v235r4dst,v233r2";
StdOutput = "file output";
StdError = "file err";
OutputSE = "lxshare0219.cern.ch";
InputSandbox = {"/home/evhtbed/scripts/x509up_u149","/home/evhtbed/sicb/mcsend","/home/evhtbed/sicb/fsize","/home/evhtbed/sicb/cdispose.class","/home/evhtbed/v235r4dst.tar.gz","/home/evhtbed/sicb/sicb/bbincl sh","/home/evhtbed/script_prod","/home/evhtbed/sicb/sicb dat","/home/evhtbed/sicb/sicb dat","/home/evhtbed/sicb/sicb dat","/home/evhtbed/v233r2.tar.gz"};
OutputSandbox = {"job txt","D ","file output","file err","job txt","job txt"};

12. 6. Inspection of replica catalog
Inspect replica catalog

13. Data Quality
Analysis of testbed data histograms on web