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    User name R. Michaels

    Log entry time 00:57:50 on June25,2000

    Entry number 44845

    keyword=re: delayed end-run entries

    Here is some reasoning for why some end-run halog updates
    are delayed by several hours. I credit M. Rvachev for figuring
    out much of this, though nobody was able to solve it.

    Problem seems to be with 'caget' used in scripts to get EPICS
    variables. If you look at the process list on adaqs2, you typically
    see at least one 'caget' command which is hanging. If you kill it
    with 'kill -9', it will end (and data appear normal), but the next
    'caget' command in the script's list will hang. Apparently, as long
    as one 'caget' command is hanging, all others function. No particular
    variable or network destination is affected; all are the same.

    Now, every end-run we clean up processes by killing caget's, among
    other things. So, after enough runs the entire list of variables is cycled
    through, and the hung up end-run script finishes (and then the next one
    gets hung up for hours).

    We thought caget might get hung up because it has something to
    print to stderr or stdout which it cannot inside the scripts. But piping
    these to /dev/null did not help. Other things were tried too. If
    someone has a good idea how to fix this, let me know (and not just
    a band-aid fix).

    Finally, I point out that all start-run, end-run, halog-com, and halog-end
    files are written in obvious format to /home/adev/epics/runfiles and will
    be saved at end of experiment. It is another (and trivial) database.