AH00024: Couldn't set permissions on the ssl-cache mutex; check User and Group directives

Question

I have compiled Apache 2.4.10 and PHP 5 in a jailed environment. When I try to start Apache by enabling SSL it is giving error logs like this :

**ERROR: [Wed Mar 11 11:47:34.958947 2015] [core:emerg] [pid 29267:tid 139645284288256] (22)Invalid argument: AH00024: Couldn't set permissions on the ssl-cache mutex; check User and Group directives
AH00016: Configuration Failed**

**compiled :**

Apache  : 2.4.10

openssl :openssl-1.0.1i 

pcre-8.35

Answer 1

Seems a permission issue with the mutex (file).

Check the path to the ssl mutex (specified in the configuration as SSLMutex) -- and verify that the user the webserver runs 'as' (eg www) is allowed to write in that directory; and is allowed 'r' and 'x' along its path.

Alternatively - use a mutex type that does not need a file: See http://httpd.apache.org/docs/2.2/mod/mod_ssl.html#sslmutex for suggestions and tradeoffs.

Answer 2

The error indicates that there is a discrepancy between the user the webserver runs under and the location where it tries to write something related to the ssl cache.

The user and group on CentOS 7 for example is apache, you can find that as a directive in /etc/httpd/conf/httpd.conf (User apache).

The same goes for Group (Group apache).

You have to verify that user apache in this case has access to the location. Most variable files go in to the run subdirectory. Also note Dirk-Willem's remark: you can change the mutex type if that is more convenient in your case.