What to log when there is a problem with the service

Whenever is a problem in the LFCs that has to be understood, you should log some data. The first thing to do is checking if there is a process taking completely one of the CPUs. For this you can use the command:
If it is, and nothing is being logged on /var/log/lfc/log then the service is stuck and you should collect and report the logs. You can start creating a directory with the date YYMMDD and put in it these files:
  • Log the last lines of the LFC log file with:
    tail -999 /var/log/lfc/log > log-YYMMDD.txt
  • Log all the processes running with:
    ps auxwwwfm > ps-YYMMDD.txt
  • Get the lfcdaemon process number with
    ps auxwww|grep lfc
    and log the list of open files with:
    lsof -p lfcdaemon_process_number > lsof-YYMMDD.txt
  • Log the top cpu processes:
    top -b -n 1 > top-YYMMDD.txt
  • The same for the netstat command:
    netstat -a > netstat-YYMMDD.txt
  • Obtain a core image with:
    gcore lfcdaemon_process_number
  • Log a list of the mapped memory regions via:
    cat /proc/lfcdaemon_process_number/maps > maps-YYMMDD.txt
  • Log gdb output:
    gdb -p lfcdaemon_process_number
    (gdb) info threads
    (gdb) set logging file gdb-YYMMDD.txt
    (gdb) set loggin on
    Call macro that does a stack dump of all threads:
    (gdb) allt 42 (42 means num of threads to log/check)
    (gdb) quit
    After running gdb, be sure that the lfcdaemon process is not blocked (does not have the T bit) when running:
    If it has it, make the daemon continue with the command:
    kill -CONT lfcdaemon_process_number

-- Main.dcollado - 18 Dec 2006

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Topic revision: r2 - 2006-12-18 - DavidCollados
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