Bug 52841 - [proxy_balancer:emerg] [pid 25593] AH01177: Failed to lookup provider 'shm' for 'slotmem': is mod_slotmem_shm loaded??
Summary: [proxy_balancer:emerg] [pid 25593] AH01177: Failed to lookup provider 'shm' f...
Alias: None
Product: Apache httpd-2
Classification: Unclassified
Component: Build (show other bugs)
Version: 2.4.9
Hardware: PC All
: P2 normal with 4 votes (vote)
Target Milestone: ---
Assignee: Apache HTTPD Bugs Mailing List
Depends on:
Reported: 2012-03-06 20:14 UTC by msubbareddy
Modified: 2016-11-22 10:05 UTC (History)
1 user (show)

possible fix (443 bytes, patch)
2014-06-02 13:10 UTC, Petr Sumbera
Details | Diff

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Description msubbareddy 2012-03-06 20:14:43 UTC
As mentioned, to use the version 1297560 in http://www.mail-archive.com/dev@httpd.apache.org/msg54299.html,

Still, issue with proxy_balancer:emerg though recompiled with http://svn.apache.org/viewvc?view=revision&revision=1297560

And, added user to use apache and group nogroup instead of daemon in conf.
but, still same issue.

[proxy_balancer:emerg] [pid 25593] AH01177: Failed to lookup provider 'shm' for 'slotmem': is mod_slotmem_shm loaded??
[:emerg] [pid 25593] AH00020: Configuration Failed, exiting

Initially, logged in Bug report:

Linux: Ubuntu 11.10 i386 x32 bit
Apache2: 2.4.1
Comment 1 msubbareddy 2012-03-07 02:04:16 UTC
Got it, this is no issue with proxy enabled option.
Its basically required to enable the corresponding required module!

[proxy_balancer:emerg] [pid 29584] AH01177: Failed to lookup provider 'shm' for 'slotmem': is mod_slotmem_shm loaded??

by uncommenting the below entry, server has ran without any issue by using 2.4.1 without any additional patches.

LoadModule slotmem_shm_module modules/mod_slotmem_shm.so
Comment 2 Petr Sumbera 2014-06-02 12:46:17 UTC
This is still reproducible. Out of box configuration file still needs to uncomment mod_slotmem_shm loading.
Comment 3 Petr Sumbera 2014-06-02 13:10:18 UTC
Created attachment 31683 [details]
possible fix
Comment 4 Gus Heck 2016-05-19 23:09:41 UTC
just hit this in 2.4.20
Comment 5 Jim Jagielski 2016-11-21 20:38:24 UTC
What are your configure options used to build httpd?
Comment 6 Petr Sumbera 2016-11-22 10:05:10 UTC
It seems that I'm no longer able to reproduce the issue with 2.4.23.

When I build Apache now without the patch (see above) httpd.conf contains:

#LoadModule slotmem_shm_module libexec/mod_slotmem_shm.so

and the httpd starts successfully.

Since I was using the patch I don't know in which version the problem disappeared.