<table class="bordered">
<tr><th>Element</th><th>Description</th></tr>
+ <tr><td><code><a href="#element.comment">comment</a></code></td>
+ <td>SSI comment</td></tr>
<tr><td><code><a href="#element.config">config</a></code></td>
<td>configure output formats</td></tr>
<tr><td><code><a href="#element.echo">echo</a></code></td>
<code class="module"><a href="../mod/mod_cgi.html">mod_cgi</a></code>, and will only be available if this
module is loaded.</p>
+ <h3><a name="element.comment" id="element.comment">The comment Element</a></h3>
+ <p>This command doesn't output anything. Its only use is to
+ add comments within a file. These comments are not printed.</p>
+
+ <p>This syntax is available in version 2.5 and later.</p>
+
+ <div class="example"><p><code>
+ <!--#comment Blah Blah Blah -->
+ </code></p></div>
+
+
<h3><a name="element.config" id="element.config">The config Element</a></h3>
<p>This command controls various aspects of the parsing. The
valid attributes are:</p>
then make each child handle a single bucket (with round-robin distribution
of the buckets at children creation time).</p>
+ <div class="note"><h3>Meaning of "online" CPU core</h3>
+ <p>On Linux (and also BSD) a CPU core can be turned on/off if
+ <a href="https://www.kernel.org/doc/Documentation/cpu-hotplug.txt">Hotplug</a>
+ is configured, therefore <code class="directive">ListenCoresBucketsRatio</code> needs to
+ take this parameter into account while calculating the number of buckets to create.</p>
+ </div>
+
<p><code class="directive">ListenCoresBucketsRatio</code> 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
<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>
+ cores should be available at runtime when this value is used.
+ The right <var>ratio</var> to obtain maximum performance needs to be calculated
+ for each target system, testing multiple values and observing the variations in your
+ key performance metrics.</p>
</div>
<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
<code>MinSpareThreads 75</code> and deal with idle threads on a server-wide
basis. If there aren't enough idle threads in the server then child
processes are created until the number of idle threads is greater
- than <var>number</var>.</p>
+ than <var>number</var>. Please also note that additional processes/threads
+ might be created if <code class="directive"><a href="#listencoresbucketsratio">ListenCoresBucketsRatio</a></code>
+ is enabled.</p>
<p><code class="module"><a href="../mod/mpm_netware.html">mpm_netware</a></code> uses a default of
<code>MinSpareThreads 10</code> and, since it is a single-process