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Posted to cvs@httpd.apache.org by yl...@apache.org on 2015/02/01 23:13:15 UTC
svn commit: r1656368 - /httpd/httpd/trunk/docs/manual/mod/mpm_common.xml
Author: ylavic
Date: Sun Feb 1 22:13:15 2015
New Revision: 1656368
URL: http://svn.apache.org/r1656368
Log:
Follow up to r1635521: ListenCoresBucketsRatio's manual.
Modified:
httpd/httpd/trunk/docs/manual/mod/mpm_common.xml
Modified: httpd/httpd/trunk/docs/manual/mod/mpm_common.xml
URL: http://svn.apache.org/viewvc/httpd/httpd/trunk/docs/manual/mod/mpm_common.xml?rev=1656368&r1=1656367&r2=1656368&view=diff
==============================================================================
--- httpd/httpd/trunk/docs/manual/mod/mpm_common.xml (original)
+++ httpd/httpd/trunk/docs/manual/mod/mpm_common.xml Sun Feb 1 22:13:15 2015
@@ -251,6 +251,44 @@ including other causes.</a></seealso>
</directivesynopsis>
<directivesynopsis>
+<name>ListenCoresBucketsRatio</name>
+<description>Ratio between the number of CPU cores (online) and the number of
+listeners' buckets</description>
+<syntax>ListenCoresBucketsRatio <var>ratio</var></syntax>
+<default>ListenCoresBucketsRatio 0 (disabled)</default>
+<contextlist><context>server config</context></contextlist>
+<modulelist>
+<module>event</module>
+<module>prefork</module>
+<module>worker</module></modulelist>
+<compatibility>Available in Apache HTTP Server 2.4.13, with a kernel supporting
+the socket option <code>SO_REUSEPORT</code> and distributing new connections
+evenly accross listening processes' (or threads') sockets using it (eg. Linux
+3.9 and later, but not the current implementations of <code>SO_REUSEPORT</code>
+in *BSDs.</compatibility>
+
+<usage>
+ <p>A <var>ratio</var> between the number of (online) CPU cores and the
+ number of listeners' buckets can be used to make Apache HTTP Server create
+ <code>num_cpu_cores / ratio</code> listening buckets, each containing its
+ own <directive>Listen</directive>-ing socket(s) on the same port(s), and
+ then make each child handle a single bucket (with round-robin distribution
+ of the buckets at children creation time).</p>
+
+ <p><directive>ListenCoresBucketsRatio</directive> can improve the
+ scalability when accepting new connections is/becomes the bottleneck.
+ On systems with a large number of CPU cores, enabling this feature has
+ been tested to show significant performances improvement and shorter
+ responses time.</p>
+
+ <p>There must be at least twice the number of CPU cores than the
+ configured <var>ratio</var> for this to be active. The recommended
+ <var>ratio</var> is <code>8</code>, hence at least <code>16</code>
+ cores should be available at runtime when this value is used.</p>
+</usage>
+</directivesynopsis>
+
+<directivesynopsis>
<name>ListenBackLog</name>
<description>Maximum length of the queue of pending connections</description>
<syntax>ListenBacklog <var>backlog</var></syntax>