mod_so/8132: Module limit reached while loading already compiled-in modules

[Bryan Mayland <bm...@leoninedev.com>]

>Number:         8132
>Category:       mod_so
>Synopsis:       Module limit reached while loading already compiled-in modules
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    apache
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   apache
>Arrival-Date:   Fri Aug 03 05:50:00 PDT 2001
>Closed-Date:
>Last-Modified:
>Originator:     bmayland@leoninedev.com
>Release:        1.3.20
>Organization:
apache
>Environment:
Linux linus 2.2.19 #37 Mon Apr 23 15:50:11 EDT 2001 i686 unknown
gcc version 2.7.2.3
>Description:
I had a system which every 2 restarts apache would die with a
'httpd: module "mod_alias.c" could not be loaded, because the dynamic module limit was reached. Please increase DYNAMIC_MODULE_LIMIT and recompile'
This was preceded by numerous '[error] Cannot remove module mod_env.c: not found in module list' for 10 or so modules.  The thing was, these modules are compiled into my apache binary.  I tracked the problem down to a configuration issue, whereas my httpd.conf file had a LoadModule line for each of the of the compiled-in modules.  It seems like apache would count the LoadModule, but then not be able to unload it on SIGHUP (because it never was actually loaded) and not decrement the module count.  Eventually, the limit would be reached after 2 restarts and apache would exit.
>How-To-Repeat:
Add a LoadModule line into httpd.conf for something listed by httpd -l.  Now send several SIGHUPs to httpd, as soon as the module limit is reached, it's over.
>Fix:
Get smarter admins who don't put LoadModule lines in their conf for things which are compiled-in.  Can you somehow shock the person at the keyboard?  Even across an SSH xterm?  :)
>Release-Note:
>Audit-Trail:
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