mod_prctl (Linux only)

mod_prctl is required to make core dumps possible with most levels of IHS 1.3 on Linux 2.4 kernels. This is in addition to requirements for configuring ulimits and CoreDumpDirectory as appropriate.

Supported server versions:

IHS 1.3.12.x, 1.3.19.x, 1.3.26.x, 1.3.28 on Linux

The following IHS 1.3 levels have the feature integrated, and mod_prctl is not necessary:

  • 1.3.19.x: 1.3.19.6 + e-fix PQ87084 or PQ90262, or any subsequent PTF
  • 1.3.26.x: 1.3.26.2 + e-fix PQ87084 or PQ90262, or any subsequent PTF
  • 1.3.28.1, or any subsequent PTF

    (Note: The version of this module for IHS 2.0 and above is described here.)

    IBM recommendation

    Any IHS 1.3 user running on a Linux 2.4 kernel should have this module installed and activated, unless using a level of IHS which has the feature integrated.

    Installation

    Copy mod_prctl.so for your platform to the libexec directory in the web server installation location (e.g., to /usr/HTTPServer/libexec).

    Activation

    Add the following directive after existing LoadModule directives:

    LoadModule prctl_module libexec/mod_prctl.so
    

    Add the following directive after existing AddModule directives:

    AddModule mod_prctl.c
    

    Restart the server so that the updated configuration takes effect.

    As long as IHS or Apache initializes with no error messages, the module was successful. If you try to use it on a level of Linux that doesn't have the proper support, it may fail to load or it may log a run-time error such as the following:

    [Tue Apr 22 14:42:04 2003] [alert] (22)Invalid argument: mod_prctl:
    set dumpable failed - this child will not coredump after software
    errors
    

    The module does not affect request processing in any way. It does its work when new child processes are created and stays out of the way afterwards.

    Deactivation

    Comment out the LoadModule and AddModule directives added as part of the activation step.

    Restart the server so that the updated configuration takes effect.