Slide 38 of 115
Notes:
This configures the SSL engine's semaphore (aka. lock) which is used for mutual exclusion of operations which have to be done in a synchronized way between the pre-forked Apache server processes. This directive can only be used in the global server context because it's only useful to have one global mutex.
The following Mutex types are available:
none - This is the default where no Mutex is used at all. Use it at your own risk. But because currently the Mutex is mainly used for synchronizing write access to the SSL Session Cache you can live without it as long as you accept a sometimes garbled Session Cache. So it's not recommended to leave this the default. Instead configure a real Mutex.
file:/path/to/mutex - This is the portable and (under Unix) always provided Mutex variant where a physical (lock-)file is used as the Mutex. Always use a local disk filesystem for /path/to/mutex and never a file residing on a NFS- or AFS-filesystem. Note: Internally, the Process ID (PID) of the Apache parent process is automatically appended to /path/to/mutex to make it unique, so you don't have to worry about conflicts yourself. Notice that this type of mutex is not available under the Win32 environment. There you have to use the semaphore mutex.
sem - Not implemented for MPE!
Example:
SSLMutex file:/usr/local/apache/logs/ssl_mutex
