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<meta name="Description" content="Cherokee is a flexible, very fast, lightweight Web server. It is implemented entirely in C, and has no dependencies beyond a standard C library. It is embeddable and extensible with plug-ins. It supports on-the-fly configuration by reading files or strings, TLS/SSL (via GNUTLS or OpenSSL), virtual hosts, authentication, cache friendly features, PHP, custom error management, and much more." />
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<h2 id="_a_href_index_html_index_a_8594_a_href_other_html_other_information_a"><a href="index.html">Index</a> → <a href="other.html">Other information</a></h2>
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<h2 id="_other_front_line_cache">Other: Front-line Cache</h2>
<div class="sectionbody">
<div class="paragraph"><p>Cherokee has very sophisticated content caching mechanisms,
allowing it to cache anything (static files, dynamic content, etc.).
Cherokee’s NEW version 1.2.3 Front-line Cache
replaces well known independent front-line caches (i.e., Varnish, Squid, etc.).
Independent front-line caches add additional latency to requests due to
TCPIP network based round-trips to check whether or not the content has
already been cached. With Cherokee, the front-line cache built in so
there are is no unnecessary network overhead due to caching.</p></div>
<div class="paragraph"><p>Front-line cache accelerates HTTP delivery even on content-heavy
dynamic websites (see example and notes on caching where cookies exist
and how to selectively ignore cookies).</p></div>
<div class="paragraph"><p>Caching policies can be specified on a per-rule basis. Caching of
content is decided by two things:</p></div>
<div class="olist arabic"><ol class="arabic">
<li>
<p>
Headers returned by the back-end (i.e., Expires Header).
</p>
</li>
<li>
<p>
Whatever is specified in the matching rule.
</p>
</li>
</ol></div>
<div class="paragraph"><p>Caching can be customized for each and every rule of your virtual
server’s configuration, by specifying any of the three settings
available on a per-rule basis in the <tt>Content Caching</tt> section:
<em>Leave unset</em>, <em>Allow</em> and <em>Forbid</em>.</p></div>
<div class="olist arabic"><ol class="arabic">
<li>
<p>
<em>Leave unset</em> option means that whenever a rule is applied it will not
change the status of the caching setting that has been inherited from
previously matched rules.
</p>
</li>
<li>
<p>
<em>Forbid</em> will disable caching of
the rule
</p>
</li>
<li>
<p>
<em>Allow</em> will cache whatever <strong>can</strong> be cached.
</p>
</li>
</ol></div>
<div class="paragraph"><p>Any HTTP content can be cached by Cherokee, except the following:</p></div>
<div class="olist arabic"><ol class="arabic">
<li>
<p>
Content in a SSL/TLS stream.
</p>
</li>
<li>
<p>
Content that is server after having matched an authentication rule.
</p>
</li>
<li>
<p>
Rules that have set any of the properties <em>No store</em>, <em>No
Transform</em>, <em>Must Revalidate</em>, or <em>Proxies Revalidate</em>.
</p>
</li>
<li>
<p>
Responses to user petitions requesting specific ranges.
</p>
</li>
<li>
<p>
Responses where the back-end sets a cookie (although you can tell Cherokee
to ignore such cookies).
</p>
</li>
</ol></div>
<div class="paragraph"><p>By default, content that includes cookies are not cached, but the
setting to allow caching on a rule gives you the ability to
disregard cookies using regular expressions (so even that content
can be cached).</p></div>
<div class="paragraph"><p>Cherokee’s rules provide for great flexibility and control over caching.
For instance, take the following example where we never cache content from a
restricted "members" section of a website, while allowing Cherokee to always
cache the contents of another section of the website regardless of presence of cookies,
by prepending two rules to the behavior rule list:</p></div>
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<div class="content">
<pre><tt>Fullpath: /site/index.php - Non-final - Cache: Disregarded Cookies '.*', Expiration.
Fullpath: /site/members/index.php - Non-final - Cache: Expiration: 1970</tt></pre>
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