IBM Support

IV00648: UNNECESSARY LARGESEND THROTTLING RESULTING IN POOR PERFORMANCE

Subscribe

You can track all active APARs for this component.

 

APAR status

  • Closed as fixed if next.

Error description

  • Largesend can stop sending data even though there is
    enough
    data in the socket send buffer and the receive window and
    congestion window are both non-zero and allow a send.
    This
    results in poor performance when largesend is turned on.
    Further performance is improved vastly when largesend is
    turned off.
    
    This will likely occur when there are packet drops when
    doing largesend and when the receive buffer size is
    really
    large.
    

Local fix

  • Reduce receive window on receiver or make it equal to the
    sendspace on the sender. This will alleviate the
    performance issue but not fix it completely.
    

Problem summary

  • When largesend is ON, customer will face poor network
    performance issue.
    

Problem conclusion

Temporary fix

Comments

  • This APAR is being closed FIN. This means that a solution to
    this APAR is expected to be delivered from IBM in a release
    (if any) to be available within the next 24 months.
    

APAR Information

  • APAR number

    IV00648

  • Reported component name

    AIX 610 STD EDI

  • Reported component ID

    5765G6200

  • Reported release

    610

  • Status

    CLOSED FIN

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Submitted date

    2011-05-18

  • Closed date

    2012-03-20

  • Last modified date

    2013-01-15

Fix information

Applicable component levels

  • R610 PSY

       UP

[{"Business Unit":{"code":"BU054","label":"Systems w\/TPS"},"Product":{"code":"SSMV87","label":"AIX 6.1 Enterprise Edition"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"610","Edition":"","Line of Business":{"code":"LOB08","label":"Cognitive Systems"}},{"Business Unit":{"code":"BU058","label":"IBM Infrastructure w\/TPS"},"Product":{"code":"SSMVAX","label":"AIX Express Edition"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"610","Edition":"","Line of Business":{"code":"LOB08","label":"Cognitive Systems"}},{"Business Unit":{"code":"BU054","label":"Systems w\/TPS"},"Product":{"code":"SSAUMY","label":"IBM AIX Enterprise Edition"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"610","Edition":"","Line of Business":{"code":"","label":""}},{"Business Unit":{"code":"BU054","label":"Systems w\/TPS"},"Product":{"code":"SG11Q","label":"AIX 6.1 HIPERS, APARs and Fixes"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"610","Edition":"","Line of Business":{"code":"","label":""}}]

Document Information

Modified date:
15 January 2013