Example

Return-Path: Delivered-To: apmail-httpd-cvs-archive@httpd.apache.org Received: (qmail 59265 invoked by uid 500); 13 Mar 2003 21:23:16 -0000 Mailing-List: contact cvs-help@httpd.apache.org; run by ezmlm Precedence: bulk Reply-To: dev@httpd.apache.org list-help: list-unsubscribe: list-post: Delivered-To: mailing list cvs@httpd.apache.org Received: (qmail 59205 invoked by uid 500); 13 Mar 2003 21:23:15 -0000 Delivered-To: apmail-httpd-2.0-cvs@apache.org Date: 13 Mar 2003 21:23:14 -0000 Message-ID: <20030313212314.87813.qmail@icarus.apache.org> From: jim@apache.org To: httpd-2.0-cvs@apache.org Subject: cvs commit: httpd-2.0/docs/manual/mod mod_ssl.xml X-Spam-Rating: daedalus.apache.org 1.6.2 0/1000/N jim 2003/03/13 13:23:14 Modified: docs/manual/mod mod_ssl.xml Log: Document the SSLMutex directives Revision Changes Path 1.12 +45 -12 httpd-2.0/docs/manual/mod/mod_ssl.xml Index: mod_ssl.xml =================================================================== RCS file: /home/cvs/httpd-2.0/docs/manual/mod/mod_ssl.xml,v retrieving revision 1.11 retrieving revision 1.12 diff -u -r1.11 -r1.12 --- mod_ssl.xml 19 Jan 2003 03:35:01 -0000 1.11 +++ mod_ssl.xml 13 Mar 2003 21:23:13 -0000 1.12 @@ -180,34 +180,67 @@ 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.

+global server context because it's only useful to have one global mutex. +This directive is designed to closely match the +AcceptMutex directive

The following Mutex types are available:

none +
none | no
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 +
posixsem +
+ This is an elegant Mutex variant where a Posix Semaphore is used when possible. + It is only available when the underlying platform + and APR supports it.
sysvsem +
+ This is a somewhat elegant Mutex variant where a SystemV IPC Semaphore is used when + possible. It is possible to "leak" SysV semaphores if processes crash before + the semaphore is removed. It is only available when the underlying platform + and APR supports it.
sem +
+ This directive tells the SSL Module to pick the "best" semaphore implementation + available to it, choosing between Posix and SystemV IPC, in that order. It is only + available when the underlying platform and APR supports at least one of the 2.
pthread
- 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 + This directive tells the SSL Module to use Posix thread mutexes. It is only available + if the underlying platform and APR supports it.
fcntl:/path/to/mutex +
+ This is a portable Mutex variant where a physical (lock-)file and the fcntl() + fucntion are 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. It is only available when the underlying platform + and APR supports it. 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 +
flock:/path/to/mutex +
+ This is similar to the fcntl:/path/to/mutex method with the + exception that the flock() function is used to provide file + locking. It is only available when the underlying platform + and APR supports it.
file:/path/to/mutex +
+ This directive tells the SSL Module to pick the "best" file locking implementation + available to it, choosing between fcntl and flock, + in that order. It is only available when the underlying platform and APR supports + at least one of the 2.
default | yes
- This is the most elegant but also most non-portable Mutex variant where a - SysV IPC Semaphore (under Unix) and a Windows Mutex (under Win32) is used - when possible. It is only available when the underlying platform - supports it.

Example SSLMutex file:/usr/local/apache/logs/ssl_mutex