IBM Support

IT01019: VP PRIVATE MEMORY CACHE IS NOT DRAINED DURING FAST RECOVERY WHICH MAY LEAD TO EXCESSIVE MEMORY USAGE

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

  • Following the fix for IC90645, free memory blocks are
    periodically drained from the VP private memory cache by the
    memory thread. However, this thread is not active during fast
    recovery and so free memory blocks may not be available for use
    by other VPs. If a significant amount of time is spent in fast
    recovery, for example by the rollback of a long transaction,
    then the amount of memory in use may continue to grow.
    
    This problem may be seen in the following extract from "onstat
    -g vpcache"
    
    vpid    pid         Blocks held  Hit percentage   Free cache
    9       185         3034305      100.0 %           100.0 %
    
    Current VP total allocations from cache:   626409, Total frees:
    2004552
    
        size  cur blks   tgt blks   alloc      miss       free
    drain     draintime
        1     550066     500        314196     0          864262
    0         Thu Jan  1 05:30:00 1970
        2     1104096    500        17         0          552065
    0         Thu Jan  1 05:30:00 1970
    ...
    
    The current number of blocks shown for block sizes 1 and 2 is in
    excess of the target blocks.
    

Local fix

  • This problem may be avoided by disabling the VP private memory
    cache in the onconfig file. It may then be enabled dynamically
    using the onmode -wm or -wf command with VP_MEMORY_CACHE
    argument.
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED:                                              *
    * all users                                                    *
    ****************************************************************
    * PROBLEM DESCRIPTION:                                         *
    * See Error Description                                        *
    ****************************************************************
    * RECOMMENDATION:                                              *
    * Update to IDS-11.70.xC9                                      *
    ****************************************************************
    

Problem conclusion

  • Problem Fixed In IDS-11.70.xC9
    

Temporary fix

Comments

APAR Information

  • APAR number

    IT01019

  • Reported component name

    INFORMIX SERVER

  • Reported component ID

    5725A3900

  • Reported release

    B70

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2014-04-14

  • Closed date

    2017-06-09

  • Last modified date

    2017-06-09

  • 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

    INFORMIX SERVER

  • Fixed component ID

    5725A3900

Applicable component levels

  • RA10 PSN

       UP

[{"Business Unit":{"code":"BU053","label":"Cloud & Data Platform"},"Product":{"code":"SSGU8G","label":"Informix Servers"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"B70","Edition":"","Line of Business":{"code":"","label":""}}]

Document Information

Modified date:
09 June 2017