IBM Support

IT33014: SOME 'DB2BP' PROCESS MIGHT HANG AND NOT TERMINATE CAUSING LATER CONNECTIONS TO FAIL WITH "BAD QUEUE HANDLE" OR HANG

Subscribe to this APAR

By subscribing, you receive periodic emails alerting you to the status of the APAR, along with a link to the fix after it becomes available. You can track this item individually or track all items by product.

Notify me when this APAR changes.

Notify me when an APAR for this component changes.

 

APAR status

  • Closed as program error.

Error description

  • It is possible that some 'db2bp' process might hang and stick
    around even after a 'terminate'.
    They won't die and stay around using a process (pid) slot. This
    can be a problem if activity is high
    and 'pid' wraps around because the message queue handle being
    based on the client's pid this might lead
    to new connection attempts either hanging or failing with "Bad
    Queue Handle".
    
    The stack of the hanging 'db2bp' would show something like this:
    
      #0  0x00007faf3dea8c30 in __nanosleep_nocancel ()
      #1  0x00007faf4151ada7 in sqloSpinLockConflict ()
      #2  0x00007faf410b93f4 in
    SQLE_GLOBAL_NODES_DESC_LATCH_SCOPED::get()
      #3  0x00007faf410b7f62 in sqleInitApplicationEnvironment()
      #4  0x00007faf410b8f95 in sqleCommonInitializationForAPIs ()
      #5  0x00007faf410bca93 in sqleintr()
      #6  0x00007faf410c2970 in sqleintr_api ()
      #7  0x00000000004a55b7 in clp_bp_sigusr2 ()
      #8  <signal handler called>
      #9  0x00007faf3de64087 in _IO_padn_internal ()
      #10 0x00007faf3de40fd6 in vfprintf ()
      #11 0x00007faf3de65479 in vsprintf ()
      #12 0x00007faf3de4b128 in sprintf ()
      #13 0x00007faf410b7f8a in sqleInitApplicationEnvironment()
      #14 0x00007faf410b8f95 in sqleCommonInitializationForAPIs ()
      #15 0x00007faf41481e6e in db2ConvMonStream ()
      #16 0x000000000046f3f7 in clpbp_exe_sqlmlstap()
      #17 0x00000000004a3760 in clp_bp_con()
      #18 0x00000000004a2d1f in main ()
    
    The important part is that we call a signal handler from
    underneath sqleInitApplicationEnvironment()
    where we hold a latch. Then, from underneath the signal handler
    we call sqleInitApplicationEnvironment()
    again. And here we hang trying to acquire a latch we already
    own.
    

Local fix

Problem summary

  • ****************************************************************
    * USERS AFFECTED:                                              *
    * All                                                          *
    ****************************************************************
    * PROBLEM DESCRIPTION:                                         *
    * See Error Description                                        *
    ****************************************************************
    * RECOMMENDATION:                                              *
    * Apply v11.1m4fp6 to the server                               *
    ****************************************************************
    

Problem conclusion

  • first fix in v11.1m4fp6
    

Temporary fix

  • Local fix
    

Comments

APAR Information

  • APAR number

    IT33014

  • Reported component name

    DB2 FOR LUW

  • Reported component ID

    DB2FORLUW

  • Reported release

    B10

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2020-05-29

  • Closed date

    2021-03-31

  • Last modified date

    2021-03-31

  • APAR is sysrouted FROM one or more of the following:

  • APAR is sysrouted TO one or more of the following:

Fix information

  • Fixed component name

    DB2 FOR LUW

  • Fixed component ID

    DB2FORLUW

Applicable component levels

[{"Line of Business":{"code":"LOB10","label":"Data and AI"},"Business Unit":{"code":"BU053","label":"Cloud & Data Platform"},"Product":{"code":"SSEPGG","label":"Db2 for Linux, UNIX and Windows"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"11.1"}]

Document Information

Modified date:
01 April 2021