DB2 FOR LUW / DB2FORLUW / B10 - DB2

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  
  #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.

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

Date  - problem reported    :
Date  - problem closed      :
Date  - last modified       :

29.05.2020
31.03.2021
31.03.2021