FileStager

Introduction to the FileStager package

Copying of a file should start at the same time that the previous file is opened for processing. Under normal circumstances (network not saturated, amount of event processing ~10ms, file sizes ~2GB) staging finishes earlier than processing, so the stager effectively performs like processing over local files. If staging of a file is not finished before it is necessary for processing, the FileStager will block until the transfer is completed. The input files specified in the job options should be picked up by the FileStager package and translated to local URLs which the EventSelector will pick up for the job.

Requirements for using the File Stager

• A valid grid certificate

• Grid environment setup correctly:

     source /global/ices/lcg/glite3.2.4/external/etc/profile.d/grid-env.sh

Troubleshooting

    Error with lcg_cp utility!Error message: Some error message from the Lcg_util middleware
    Checking file size:File does not exist, or problems with gfal library.

This is usually indication that no valid certificate exists, or that the grid environment is not setup correctly. Try:

    echo $LCG_LOCATION

to see if this environment variable is set correctly. It should point to some directory like

   /global/ices/lcg/glite3.2.4/lcg

Also try:

  lcg-cp -v --vo lhcb srm://aFiletoStage file:/tmp/localFileCopy

If this isn't working correctly, ask a grid expert to solve the problem.

   No permission to write in temporary directory <someusername>. Switching back to default <$TMPDIR>, or else </tmp>.
   Default tmpdir set to <someusername>

The temporary directory is where the staged Grid files are stored, in the course of the job execution.

You can override the default location by including the following line in the jobOption file

   FileStagerSvc().BaseTmpdir="/some/temp/directory/with/sufficient/space"