IBM Support

PI70081: WHEN USING AIO, PERFORMANCE ISSUES CAN OCCUR IF A HIGH NUMBER OF OPEN CONNECTIONS ARE OPENED ON A POLLSET

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You can track all active APARs for this component.

 

APAR status

  • Closed as program error.

Error description

  • On AIX only with AIO enabled, it's possible for a high number
    of concurrent open connections (upwards of 20,000) to cause
    performance problems.
    

Local fix

  • N/A
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED:  IBM WebSphere Application Server Version    *
    *                  8.5.5 and 9.0 users of AIO on AIX           *
    ****************************************************************
    * PROBLEM DESCRIPTION: Slower performance can be experienced   *
    *                      on AIX with AIO enabled.                *
    ****************************************************************
    * RECOMMENDATION:                                              *
    ****************************************************************
    When there are around 20,000 connections there can be a
    performance issue. The problem only happens on AIX when AIO is
    enabled.
    

Problem conclusion

  • AIO native code was modified to raise the max number of
    connections for a poll set to 60,000.
    
    The fix for this APAR is currently targeted for inclusion in
    fix packs 8.5.5.12 and 9.0.0.3.  Please refer to the
    Recommended Updates page for delivery information:
    http://www.ibm.com/support/docview.wss?rs=180&uid=swg27004980
    

Temporary fix

Comments

APAR Information

  • APAR number

    PI70081

  • Reported component name

    WEBS APP SERV N

  • Reported component ID

    5724H8800

  • Reported release

    850

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date

    2016-10-03

  • Closed date

    2017-02-14

  • Last modified date

    2017-02-14

  • 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

    WEBS APP SERV N

  • Fixed component ID

    5724H8800

Applicable component levels

  • R850 PSY

       UP

  • R900 PSY

       UP

[{"Business Unit":{"code":"BU053","label":"Cloud \u0026 Data Platform"},"Product":{"code":"SSEQTP","label":"WebSphere Application Server"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"850","Line of Business":{"code":"LOB36","label":"IBM Automation"}}]

Document Information

Modified date:
18 October 2021