PI54757: Delay allocating an IHS thread until data is available on a new inbound TCP connection.

7.0.0.41: WebSphere Application Server V7.0 Fix Pack 41
8.5.5.10: WebSphere Application Server V8.5.5 Fix Pack 10
8.5.5.11: WebSphere Application Server V8.5.5 Fix Pack 11
8.0.0.13: WebSphere Application Server V8.0 Fix Pack 13
7.0.0.43: WebSphere Application Server V7.0 Fix Pack 43
8.5.5.12: WebSphere Application Server V8.5.5 Fix Pack 12
8.0.0.14: WebSphere Application Server V8.0 Fix Pack 14
8.5.5.13: WebSphere Application Server V8.5.5 Fix Pack 13
7.0.0.45: WebSphere Application Server V7.0 Fix Pack 45
8.0.0.15: WebSphere Application Server V8.0 Fix Pack 15
7.0.0.45: Java SDK 1.6 SR16 FP60 Cumulative Fix for WebSphere Application Server
7.0.0.41: Java SDK 1.6 SR16 FP20 Cumulative Fix for WebSphere Application Server
7.0.0.43: Java SDK 1.6 SR16 FP41 Cumulative Fix for WebSphere Application Server
8.5.5.14: WebSphere Application Server V8.5.5 Fix Pack 14
8.5.5.15: WebSphere Application Server V8.5.5 Fix Pack 15
8.5.5.17: WebSphere Application Server V8.5.5 Fix Pack 17
8.5.5.20: WebSphere Application Server V8.5.5.20
8.5.5.18: WebSphere Application Server V8.5.5 Fix Pack 18
8.5.5.19: WebSphere Application Server V8.5.5 Fix Pack 19
8.5.5.16: WebSphere Application Server V8.5.5 Fix Pack 16
8.5.5.21: WebSphere Application Server V8.5.5.21

APAR status

• Closed as program error.

Error description

• When a new connection arrives, an IBM HTTP Server thread is
  used to call accept() and wait for a HTTP request (or a TLS
  handshake). On Linux, a non-portable option (TCP_DEFER_ACCEPT)
  allows this thread allocation to be delayed until data is
  ready.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:  Users of IBM HTTP Server on Linux           *
  ****************************************************************
  * PROBLEM DESCRIPTION: Delay allocating an IHS thread until    *
  *                      data is available on the new            *
  *                      connection.                             *
  ****************************************************************
  * RECOMMENDATION:  Apply this fix if using IBM HTTP Server on  *
  *                  Linux                                       *
  ****************************************************************
  Increase TCP_DEFER_ACCEPT to match newer Apache HTTP Servers.
  The current value of '1', if not ignored by the operating
  system entirely, is too short.
  

Problem conclusion

• The Linux TCP_DEFER_ACCEPT value was increased to allow
  webserver threads to not be woken until data is available.
  
  This fix is targeted for IBM HTTP Server fix packs:
  - 7.0.0.41
  - 8.0.0.13
  - 8.5.5.10
  

Temporary fix

Comments

APAR Information

• 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

  IBM HTTP SERVER

• Fixed component ID

  5724J0801

Applicable component levels

• R700 PSY

     UP

• R800 PSY

     UP

• R850 PSY

     UP