CMS Software at RAL

Fortran Code• Software is mirrored into RAL AFS cell every 24 hours

/afs/rl.ac.uk/cms/

• Binary libraries available for:

HP HP-UX 10.20

Linux Redhat 5.1/5.2

Sun Solaris 2.6

• Includes:

CMSIM versions 113-118

CMSJET

PYTHIA Glenn Patrick, CMS(UK), 30.11.1999

RAL Particle Physics Unix Services

100 Megabit Switched Network

HP LINUX SUN

1 Terabyte Disk

Scratch

NIS

/home userids

FDDI

AFS

Datastore

HP BATCHLINUX BATCH ?

Platforms & ProblemsHP-UX

•PA7000 and PA8000 chip architectures cause problems: Updating is done with PA8000 code which only runs on

5 fastest (newest) CSF nodes. Cannot target particular batch nodes with NQS.

Require special queue or recompile according to node.• HP-UX deprecated within CMS.• HP-UX being phased out at CERN and RAL over the

next year. • Far greater capacity on Linux & future expansion.

Conclusion …... migrate to Linux.

0

50

100

150

200

250

300

HP CSF 1H99 2H99 2Q00

Systems

P450 equiv

P350 equiv

Predicted RAL-CSF Linux Profile

LinuxCMSIM successfully ported onto CSF Linux nodes.

BUT Have to take care to set PATH to pick correct compilers. System compilers are default and these appear in /usr/bin which usually comes before /usr/local/bin which contains the CERN versions of the compilers. Sometimes differences between the CERN compiler versions on csflnx(egcs -1.1.1) & cmslx( egcs -1.1.2). Sometimes the CERN library src directories disappear due to ASIS updating - need for GEANT. Problems with old versions of CMSIM due to different FORTRAN libraries - what do CERN do?

Linux : ATHLON(AMD K7) 600 MHz CPU versus Pentium II 450 MHz CPU Benchmarks

Speedup

H1 Simulation

H1 Reconstruction

1.41

1.24

HERWIG/ LHC 1.25

ATLAS Track reconstruction 1.28

Scattering matrix calculation 1.75

CMSIM 1.35

600MHZ/ 450MHZ 1.333

PYTHIA

CMSIM116GEANT3

DigitisationORCA

Objectivity

Pileup

Analysis

EXISTS FORTRAN

UNKNOWN OO

OO Software

Investigated setting up RAL as remote developer site and implementing developer spaces for OO projects.

• SCRAM installed.

• ORCA environment downloaded - Web to AFS.

Some initial security problems.

Some conflicts with FORTRAN updating.

LHC++ software required to build the code!! Need HTL, Objectivity,OpenGL, ObjectSpace, Iris Explorer, Iris Explorer, etc

CMS Software Components

LHC++ ODBMS Geant4 CLHEPHepExplorer

HTL

C++ standard library

Extension toolkit

LHC++

Of benefit to all experiments, so John Gordon took on main task of installing code in local AFS space:

Institute authority for commercial components

/afs/rl.ac.uk/sw/lhcxx

•Various problems with operating systems.

•Various problems with versions, Exceed, etc.

However, I got to the stage of setting up an LHC++ environment on Linux, defining an Objectivity federation and running Iris Explorer to produce histograms.

Objectivity

Need to understand the technicalities of Objectivity.

Complicated because of number of experiments supported at RAL and possible conflicts over versions and locking mechanisms.

• Lock servers, AMS servers, performance.

• FDID identifiers (using spare BaBar numbers).

• Mass storage and data migration - disk to tape.

BaBar estimate it took 1FTE for their UK work.

Forwards? Yet to emerge from the LHC++ diversion…..

What about GEANT4, OSCAR, IGUANA, etc?

What about user environment?

Only aiming for minimal system and capability.

Work exceeds available effort - not at all what I had in mind.

Need to see benefit by getting to stage of processing physics events beyond CMSIM.

JIF bid is needed if you want to do this seriously on a large-scale!