PM78144: IBM HTTP SERVER LARGE LOGFORMATS CANNOT BE CORRECTLY LOGGED BY PIPED LOGGERS

Fixes are available

APAR status

Closed as program error.

Error description

In IBM HTTP Server (IHS) large logformats cannot be correctly
logged by piped loggers.

Local fix

A workaround is to reduce the number of log strings used in the
LogFormat directive in IBM HTTP Server.

The customer can use multiple SHORT LogFormats with multiple
CustomLog directives to write output to multiple log files,
rather than using one LONG LogFormat for everything.

Problem summary

****************************************************************
* USERS AFFECTED:  IBM HTTP Server users with access log       *
*                  records longer than the Operating System's  *
*                  PIPE_BUF who used piped loggers (for        *
*                  example, rotatelogs)                        *
****************************************************************
* PROBLEM DESCRIPTION: Long access log records are garbled     *
*                      when                                    *
*                      using piped loggers                     *
****************************************************************
* RECOMMENDATION:                                              *
****************************************************************
When IBM HTTP Server writes long access log records to a pipe,
the log is garbled.  POSIX only guarantees atomic writes for
the first PIPE_BUF (4k on Linux) worth of data when writing to
a Unix pipe.

Problem conclusion

mod_log_config is changed to support a new buffer size
parameter
on the BufferedLogs directive, coded like this:

BufferedLogs on 40000     # 3rd arg is the buffer size in bytes

When the access log is piped, such as with rotatelogs, and the
specified buffer size is greater than PIPE_BUF, IBM HTTP
Server will obtain a cross-process lock while writing the
buffer to the pipe. This prevents other processes from writing
to the pipe while the lock is held, and prevents the
corruption of the log.

Temporary fix

Comments

APAR Information

APAR number
PM78144
Reported component name
IBM HTTP SERVER
Reported component ID
5724J0801
Reported release
700
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2012-11-29
Closed date
2013-01-11
Last modified date
2013-01-11

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

R61A PSY
UP
R61H PSY
UP
R61I PSY
UP
R61P PSY
UP
R61S PSY
UP
R61W PSY
UP
R61Z PSY
UP
R700 PSY
UP
R800 PSY
UP
R850 PSY
UP

[{"Business Unit":{"code":"BU059","label":"IBM Software w\/o TPS"},"Product":{"code":"SSEQTJ","label":"IBM HTTP Server"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"7.0","Line of Business":{"code":"LOB45","label":"Automation"}}]

Document Information

Modified date:
07 September 2022

Tips

PM78144: IBM HTTP SERVER LARGE LOGFORMATS CANNOT BE CORRECTLY LOGGED BY PIPED LOGGERS

Fixes are available

Subscribe

APAR status

Closed as program error.

Error description

Local fix

Problem summary

Problem conclusion

Temporary fix

Comments

APAR Information

APAR number

Reported component name

Reported component ID

Reported release

Status

PE

HIPER

Special Attention

Submitted date

Closed date

Last modified date

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

Fixed component ID

Applicable component levels

R61A PSY

R61H PSY

R61I PSY

R61P PSY

R61S PSY

R61W PSY

R61Z PSY

R700 PSY

R800 PSY

R850 PSY

Document Information

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