IBM Support

IV66464: REDUCE JAVA HEAP MEMORY USAGE FOR JAVA COLLECTIONS

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APAR status

  • Closed as program error.

Error description

  • Error Message: N/A
    .
    Stack Trace: N/A
    .
    N/A
    

Local fix

Problem summary

  • When running Java applications (particularly middleware) there
    is a large volume of empty collections that exist in
    applications. A number of these empty collections have however
    been allocated with a backing array (default capacities
    generally vary between 10 and 16 entries).
    

Problem conclusion

  • The problem is that application create too many empty
    collections and these empty collections are never used, this a
    big waste of resource. Many java util collections such as
    HashMap/Hashtable have a backing array to hold the data, and the
    backing array is initialized to default capacity. This
    initialization of backing array can be lazied to reduce
    footprint.
    .
    This APAR will be fixed in the following Java Releases:
       7 R1 SR2 FP10  (7.1.2.10)
       7    SR8 FP10  (7.0.8.10)
    .
    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

    IV66464

  • Reported component name

    JAVA CLASS LIBS

  • Reported component ID

    620700130

  • Reported release

    700

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2014-10-31

  • Closed date

    2014-10-31

  • Last modified date

    2014-10-31

  • 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

    JAVA CLASS LIBS

  • Fixed component ID

    620700130

Applicable component levels

  • R700 PSY

       UP



Document information

More support for: Runtimes for Java Technology
Java Class Libraries

Software version: 700

Reference #: IV66464

Modified date: 31 October 2014