IBM Support

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

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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 number

    IT31758

  • 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

    2020-02-04

  • Closed date

    2021-03-26

  • Last modified date

    2021-03-26

  • 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:
27 March 2021