Runtime Environment for DZero

1
Runtime Environment for D-Zero

• Jonathan Hays
• Imperial College
• Thursday 13th September 2001

2
Introduction

• Why?
• Why do we need a common runtime environment?
• What?
• What is meant by a runtime environment?
• How?
• How could it be implemented?
• Use Cases
• How might it be used?

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Why?

• Make it easier to run the major exes
• A major problem with configuration files,
  parameters, scripts
• Simplify generation of (mini)tarfiles for export
• Remove need for custom scripts for each release
• Solve maintenance problem
• Spread support load out among the developers

4
What?

• A common user interface for executing the major
  executables (Reco, sim, trigsim, d0gstar etc.)
• An environment which does not require the source
  code trees to be present.

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How?

• Use d0tools to provide the common interface (it
  already does this to a large extent)
• createRuntimeEnv --releaset01.60.00 --dirmydir
  --d0distyes tarfilenone
• runScriptRunner, runD0TrigSim, runD0Reco etc
• Generalise d0tools by removing the package
  specific components out of d0tools
• These are mainly scripts which set up various
  configuration files. These tasks can be moved
  into the packages themselves. This is made
  possible by defining a specific directory
  structure that d0tools will assume.

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How?

• myRuntimeDirectory_v1/
• bin/Linux-2_KCC_4_0/myExe
• lib/Linux-2_KCC_4_0/myLib.so
• rundata/
• d0trigsim/
• myconfig.dat
• trigger_lists/
• trig-mcc3-1.2.xml
• d0reco/
• coor/
• sam/
• etc. etc. etc.

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How?

• This directory tree should contain every file
  needed to successfully run the desired
  executable.
• On systems where d0 code distribution is
  available use symbolic links.
• This is necessary for compatibility with the
  build environment
• Creating minitarfile becomes almost trivial
• Tar up the directory tree resolving all links and
  add a simple bootstrap script

8
Use cases

• User running on d0mino
• Use symlinks to point back to the release to be
  efficient with disk space and time required to
  initialise the environment
• Problems
• Should they be allowed to edit configurations? If
  so, how would this be implemented?

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Use Cases

• Running on the farms
• Tarfile is created on a system where the release
  is present probably as part of the build
  process and then shipped to appropriate place
• Does not require d0 code release to be present
• Problems
• What exactly should go in the tarfile?
• How much can be assumed about target node?
• What problems are there associated with moving
  across similar platform eg. RedHat 6 -gt RedHat 7?

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Use Cases

• Running on d0mino as a developer
• At any point during code development should be
  able to set up the runtime environment and test
  their local copy of the executable
• Problems
• Runtime scripts have to be aware of existing
  build environment and act intelligently
• Have to be able to edit configurations and RCPs
  without problems.