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IT08512: TARGET REPLICATION SERVER UNEXPECTED HIGH MEMORY USAGE IN PREALLOCCHUNKFORINVUPDATEITEMS

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APAR status

  • Closed as program error.

Error description

  • During Node Replication, on the Target Server, the user may see
    unexpected high memory usage for the dsmserv process.
    Though the 'show alloc' data reports this memory has been
    released by the dsmserv process, the system does not free this
    memory for other processes in a timely manner.  The user may
    also see unexpected system memory paging.
    
    High memory usage can be seen when many Node Replication
    sessions are working on the same filespace and get blocked on
    the target server.  This is typically caused by issuing a
    separate Replicate Node command for only one or a few
    filespaces, and keeping the default MAXSESSions at ten.
    
    Tivoli Storage Manager Versions Affected: V6.3 V7.1
    
    L2 Diagnostics:
    Example of the Show Alloc data:
    ...
      Server-tracked memory statistics:
      ----------------------------------------------------
      Total memory allocated             74283125144 bytes
      Base MemUtil (amount requested)    74282414873 bytes
      Actual mem allocated               75771572352 bytes
    ...
    
    imqueue.c line  5118:     xxxx entries for   68399950024 bytes
    (PreAllocChunkForInvUpdateItems) thread yyy(psSessionThread
    parent=zzz)
    ...
    This one thread is using 99% of the used memory.
    
    A later Show Alloc output, for the same process, is using much
    less memory (after the Node Replication was done on the Target
    server):
    
    imqueue.c line  5118:        x entries for      31509576 bytes
    (PreAllocChunkForInvUpdateItems) thread www(psSessionThread
    parent=zzz)
    
    Initial Impact: High
    Additional Keywords: system paging crashed crash dump core out
    of memory DBMEMPERCENT
    

Local fix

  • To reduce the memory usage, use node_group_name instead of
    single node name for each REPLICATE NODE command.
    If required to use a single node name, in the REPLICATE NODE
    command, then set the MAXSESSions to 2 or 1
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED:                                              *
    * All Tivoli Storage Manager server users of node replication  *
    ****************************************************************
    * PROBLEM DESCRIPTION:                                         *
    * See Error Description                                        *
    ****************************************************************
    * RECOMMENDATION:                                              *
    * Apply fixing level when available.  This problem is          *
    * currently project to be fixed in levels 6.3.6.0 and 7.1.3.0  *
    ****************************************************************
    

Problem conclusion

  • The problem is fixed.
    Affected platforms: AIX, Solaris, Linux, Windows, and HP-UX
    

Temporary fix

Comments

APAR Information

  • APAR number

    IT08512

  • Reported component name

    TSM SERVER

  • Reported component ID

    5698ISMSV

  • Reported release

    63A

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2015-04-23

  • Closed date

    2015-05-15

  • Last modified date

    2015-05-15

  • 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

    TSM SERVER

  • Fixed component ID

    5698ISMSV

Applicable component levels

  • R63A PSY

       UP

  • R63H PSY

       UP

  • R63L PSY

       UP

  • R63S PSY

       UP

  • R63W PSY

       UP

  • R71A PSY

       UP

  • R71H PSY

       UP

  • R71L PSY

       UP

  • R71S PSY

       UP

  • R71W PSY

       UP



Document information

More support for: Tivoli Storage Manager

Software version: 63A

Reference #: IT08512

Modified date: 15 May 2015