Handling a Hung or Stalled Userid

Contributed by Mike Walter (mwalter@hewitt.com)

When a userid becomes hung with LOGOFF/FORCE PENDING, the following alternatives may be tried, some require more than class "G" privileges.

  • If you have the time, simply waiting 15 minutes for CP to perform housecleaning chores might free the userid, completing the LOGOFF or FORCE.
  • Use the public domain utility "TRACK" to determine if the userid is awaiting completion of an I/O to a particular unresponsive device.

    Use the commands:
    TRACK hungid DEV CLASS * IO PENDing
    TRACK hungid DEV CLASS * IO ACTIVE

    Note bene: As of June 2003 TRACK can be obtained from: http//vm.marist.edu/track

  • Sometimes a simple message frees up the "hungid" without further ado. From a privclass A, B, or C userid, issue:
    CP WNG hungid Hello
  • If you can (consider communication time-outs which may occur that could affect other users) before muddying the waters, get a current system dump for IBM to diagnose later. From a privclass "A' user:

    CP QUERY DUMP (then ensure that it is going to disk)
    Then: CP WNG ALL This system may be non-responsive for a few minutes while diagnostic information is obtained.
    Then: CP SNAPDUMP

  • If the ID was awaiting I/O to a terminal, simply connecting from a working terminal may free the ID. From a free terminal, issue: CP LOGON hungid HERE
  • For users logged on via TELNET terminals, issue:
    NETSTAT TELNET

    Find the matching tn3270 connection, and issue:
    NETSTAT DROP conn_num

  • "CPHX" is reported to cancel pending CP commands: ATTACH, LOCATE, LOCATEVM, and VARY ONLINE|OFFLINE (see HELP for more detail). From a privclass "A" userid, issue:
    CP CPHX hungid
  • If TRACK (above) showed an active I/O which cannot be remedied (e.g. by making a tape drive "Ready"), the I/O may be able to be cancelled. From a privclass "A" userid, issue:
    CP HALT rdev

    Due to queued I/Os or recalcitrant devices, HALT may need to be issued repeatedly until the following message is received:
    Halt was not initiated to tape nnnn because the device as not active

  • If nothing freed the hung user, open a Problem Management Report with IBM, and provide the SNAPDUMP for analysis.