APAR status
Closed as program error.
Error description
This is a flawed optimization in the event MPM to avoid frequent wakeups when a timeout event is in the near future (up to 100ms).
Local fix
N/A
Problem summary
**************************************************************** * USERS AFFECTED: All users of IBM HTTP Server 9.0 on Linux * * and z/OS * **************************************************************** * PROBLEM DESCRIPTION: Keepalive connections may be closed * * by the server up to 100 milliseconds * * early. * **************************************************************** * RECOMMENDATION: * **************************************************************** Normally IBM HTTP Server informs the client of the keepalive timeout it will use via the "Keep-Alive" HTTP response header. Some clients may use this exact value to maintain their own connection pool lifetimes. This is already subject to race conditions as the server and client will not necessarily be counting from down from the same initial time. On z/OS and Linux in 9.0 when the "event MPM" is used (default) IHS is likely to close keepalive connections close to 100ms early due to a flawed optimization. Note: IHS 8.5.5 on distributed platforms is not affected. IHS 8.5.5 on z/OS is in practice not affected as it is does not wake up as frequently to process timeouts.
Problem conclusion
The code was updated to avoid closing keepalive connections prematurely. The fix for this APAR is targeted for inclusion in IBM HTTP Server fix pack 9.0.5.4. For more information, see 'Recommended Updates for WebSphere Application Server': http://www.ibm.com/support/docview.wss?rs=180&uid=swg27004980
Temporary fix
Comments
APAR Information
APAR number
PH22727
Reported component name
IBM HTTP SERVER
Reported component ID
5724J0801
Reported release
850
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2020-02-27
Closed date
2020-03-04
Last modified date
2021-11-24
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
[{"Line of Business":{"code":"LOB45","label":"Automation"},"Business Unit":{"code":"BU059","label":"IBM Software w\/o TPS"},"Product":{"code":"SSEQTJ","label":"IBM HTTP Server"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"8.5"}]
Document Information
Modified date:
07 September 2022