IT31758: POSSIBLE SLOWDOWN (PSEUDO HANG) IF CONNECTION EVENT MONITOR IS ON ON SOLARIS

APAR status

• Closed as program error.

Error description

• If the connection event monitor is on we will collect various
  statistics when the session terminates.
  
  On Solaris when collecting memory related information we will
  use the kstat routines and that includes
  kstat_open() / kstat_close(). If hundreds of sessions happen to
  do that at the same time we might
  see them piling up in malloc/free calls underneath the
  kstat_opne()/kstat_close() calls.
  
  Typical stacks:
  
    __lwp_park() + 0x14
    mutex_lock_queue() + 0x104
    do_malloc() + 0x60
    kstat_zalloc() + 0x1c
    kstat_chain_update() + 0x198
    kstat_open() + 0x78
    sqloGetPhysicalMemoryStats() + 0xa0
    FindPoolsInSetAndBuildList() + 0x12c
    sqloGetMemoryForAgents() + 0x8c
    ...
  
  or
  
    __lwp_park() + 0x14
    mutex_lock_queue() + 0x104
    free() + 0x48
    kstat_hashed_remove_ksp() + 0xcc
    kstat_chain_free() + 0x18
    kstat_close() + 0x4
    sqloGetPhysicalMemoryStats() + 0x5e0
    FindPoolsInSetAndBuildList() + 0x12c
    sqloGetMemoryForApplications() + 0x8c
    ...
  
  Common point would be the __lwp()park() underneath malloc() or
  free().
  
  Workaround is to turn off the connection event monitoring
  

Local fix

• Workaround is to turn off the connection event monitoring
  

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * all                                                          *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * See Error Description                                        *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * upgrade to db2_v111m4fp6 or higher                           *
  ****************************************************************
  

Problem conclusion

• fixed in db2_v111m4fp6
  

Temporary fix

Comments

APAR Information

• 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