IBM Support

IV68281: INCORRECT DURATION/INTERVAL VERBOSE GC TIMES

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

  • Error Message: Times appear to be inflated close to 2xInter-GC
    intervals:<exclusive-start id="50"
    timestamp="2014-11-20T18:14:15.395"
    intervalms="830.817"><exclusive-start id="62"
    timestamp="2014-11-20T18:14:15.640"
    intervalms="477.967">According to timestamps it should be 640 -
    395 = 245ms, but reported as ?478ms.GC duration:<exclusive-start
    id="74" timestamp="2014-11-20T18:14:16.609"
    intervalms="1893.006"><exclusive-end id="85"
    timestamp="2014-11-20T18:14:16.948" durationms="661.689"
    />Duration as per timestamps should be 948 - 609 = 339ms, but
    reported as ?662ms.
    .
    Stack Trace: N/A
    .
    

Local fix

  • No workaround.
    

Problem summary

  • Rounding errors in microsecond times calculations on Windows
    64-bit cause inaccurate times in verbose GC log.
    

Problem conclusion

  • Use floating-point calculations to calculate time delta.
    .
    This APAR will be fixed in the following Java Releases:
       7    SR8 FP10  (7.0.8.10)
       6 R1 SR8 FP3   (6.1.8.3)
    .
    Contact your IBM Product's Service Team for these Service
    Refreshes and Fix Packs.
    For those running stand-alone, information about the Service
    Refreshes and Fix Packs can be found at:
               https://www.ibm.com/developerworks/java/jdk/
    

Temporary fix

Comments

APAR Information

  • APAR number

    IV68281

  • Reported component name

    J9 COMMON CODE

  • Reported component ID

    620700127

  • Reported release

    260

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2015-01-05

  • Closed date

    2015-01-05

  • Last modified date

    2015-01-05

  • 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

    J9 COMMON CODE

  • Fixed component ID

    620700127

Applicable component levels

  • R260 PSY

       UP



Document information

More support for: Runtimes for Java Technology
Virtual Machine

Software version: 260

Reference #: IV68281

Modified date: 05 January 2015