<identifier>mem_cache_module</identifier>
<summary>
+ <note type="warning">
+ This module is experimental. Documentation is still under
+ development...
+ </note>
-<note type="warning">
-This module is experimental. Documentation is still under development...
-</note>
- <p><module>mod_mem_cache</module> implements a memory based storage manager.
- <module>mod_mem_cache</module> can be configured to operate in two modes:
- caching open file descriptors or caching objects in heap storage.
+ <p>This module <em>requires</em> the service of <module
+ >mod_cache</module>. It acts as a support module for <module
+ >mod_cache</module> and provides a memory based storage manager.
+ <module>mod_mem_cache</module> can be configured to operate in two
+ modes: caching open file descriptors or caching objects in heap storage.
<module>mod_mem_cache</module> is most useful when used to cache locally
- generated content or to cache backend server content for
- <module>mod_proxy</module> configured for
- <directive module="mod_proxy">ProxyPass</directive> (aka <dfn>reverse proxy</dfn>)</p>
-
- <p>Content is stored in and retrieved from the cache using URI based keys. Content with
- access protection is not cached.</p>
+ generated content or to cache backend server content for <module
+ >mod_proxy</module> configured for <directive module="mod_proxy"
+ >ProxyPass</directive> (aka <dfn>reverse proxy</dfn>).</p>
- <note><title>Note:</title>
- <p><module>mod_mem_cache</module> requires the services of <module>mod_cache</module>.</p>
- </note>
+ <p>Content is stored in and retrieved from the cache using URI based
+ keys. Content with access protection is not cached.</p>
</summary>
+<seealso><module>mod_cache</module></seealso>
+<seealso><module>mod_disk_cache</module></seealso>
<directivesynopsis>
<name>MCacheSize</name>
-<description>The maximum amount of memory used by the cache in KBytes</description>
+<description>The maximum amount of memory used by the cache in
+KBytes</description>
<syntax>MCacheSize <var>KBytes</var></syntax>
<default>MCacheSize 100</default>
-<contextlist><context>server config</context><context>virtual host</context>
-</contextlist>
+<contextlist><context>server config</context></contextlist>
<usage>
- <p>The <directive>MCacheSize</directive> directive sets the maximum amount of memory
- to be used by the cache, in KBytes (1024-byte units). If a new object needs to be
- inserted in the cache and the size of the object is greater than the
- remaining memory, objects will be removed until the new object can be cached.
- The object to be removed is selected using the algorithm specified by
- <directive>MCacheRemovalAlgorithm</directive>.</p>
-
- <note type="warning"><title>Note:</title>
- The <directive>MCacheSize</directive> value must be greater than the value
- specified by the <directive>MCacheMaxObjectSize</directive> directive.
- </note>
-
- <example>
- MCacheSize 700000<br />
+ <p>The <directive>MCacheSize</directive> directive sets the maximum
+ amount of memory to be used by the cache, in KBytes (1024-byte units).
+ If a new object needs to be inserted in the cache and the size of the
+ object is greater than the remaining memory, objects will be removed
+ until the new object can be cached. The object to be removed is
+ selected using the algorithm specified by <directive
+ module="mod_mem_cache">MCacheRemovalAlgorithm</directive>.</p>
+
+ <example><title>Example</title>
+ MCacheSize 700000
</example>
+
+ <note><title>Note</title>
+ <p>The <directive>MCacheSize</directive> value must be greater than
+ the value specified by the <directive module="mod_mem_cache"
+ >MCacheMaxObjectSize</directive> directive.</p>
+ </note>
</usage>
</directivesynopsis>
<directivesynopsis>
<name>MCacheMaxObjectCount</name>
-<description>The maximum number of objects allowed to be placed in the cache</description>
+<description>The maximum number of objects allowed to be placed in the
+cache</description>
<syntax>MCacheMaxObjectCount <var>value</var></syntax>
<default>MCacheMaxObjectCount 1009</default>
-<contextlist><context>server config</context><context>virtual host</context>
-</contextlist>
+<contextlist><context>server config</context></contextlist>
<usage>
- <p>The <directive>MCacheMaxObjectCount</directive> directive sets the maximum
- number of objects to be cached. If a new object needs to be inserted in the cache
- and the maximum number of objects has been reached, an object will be removed
- to allow the new object to be cached. The object to be removed is selected using
- the algorithm specified by <directive>MCacheRemovalAlgorithm</directive>.</p>
-
- <note><title>Note:</title>
- The value of <directive>MCacheMaxObjectCount</directive> is used to create
- the open hash table.
- </note>
-
- <example>
- MCacheMaxObjectCount 13001<br />
+ <p>The <directive>MCacheMaxObjectCount</directive> directive sets the
+ maximum number of objects to be cached. The value is used to create the
+ open hash table. If a new object needs to be inserted in the cache and
+ the maximum number of objects has been reached, an object will be
+ removed to allow the new object to be cached. The object to be removed
+ is selected using the algorithm specified by <directive
+ module="mod_mem_cache">MCacheRemovalAlgorithm</directive>.</p>
+
+ <example><title>Example</title>
+ MCacheMaxObjectCount 13001
</example>
</usage>
</directivesynopsis>
cache</description>
<syntax>MCacheMinObjectSize <var>bytes</var></syntax>
<default>MCacheMinObjectSize 0</default>
-<contextlist><context>server config</context><context>virtual host</context>
-</contextlist>
+<contextlist><context>server config</context></contextlist>
<usage>
- <p>The <directive>MCacheMinObjectSize</directive> directive sets the minimum
- size in bytes of a document for it to be considered cacheable.</p>
+ <p>The <directive>MCacheMinObjectSize</directive> directive sets the
+ minimum size in bytes of a document for it to be considered
+ cacheable.</p>
- <example>
- MCacheMinObjectSize 10000<br />
+ <example><title>Example</title>
+ MCacheMinObjectSize 10000
</example>
</usage>
</directivesynopsis>
cache</description>
<syntax>MCacheMaxObjectSize <var>bytes</var></syntax>
<default>MCacheMaxObjectSize 10000</default>
-<contextlist><context>server config</context><context>virtual host</context>
-</contextlist>
+<contextlist><context>server config</context></contextlist>
<usage>
- <p>The <directive>MCacheMaxObjectSize</directive> directive sets the maximum
- allowable size, in bytes, of a document for it to be considered cacheable.</p>
+ <p>The <directive>MCacheMaxObjectSize</directive> directive sets the
+ maximum allowable size, in bytes, of a document for it to be considered
+ cacheable.</p>
- <note type="warning"><title>Note:</title>
- The value of <directive>MCacheMaxObjectSize</directive> must be greater
- than the value specified by the <directive>MCacheMinObjectSize</directive>
- directive.
- </note>
-
- <example>
- MCacheMaxObjectSize 6400000<br />
+ <example><title>Example</title>
+ MCacheMaxObjectSize 6400000
</example>
+
+ <note><title>Note</title>
+ <p>The value of <directive>MCacheMaxObjectSize</directive> must be
+ greater than the value specified by the <directive
+ module="mod_mem_cache">MCacheMinObjectSize</directive> directive.</p>
+ </note>
</usage>
</directivesynopsis>
<name>MCacheRemovalAlgorithm</name>
<description>The algorithm used to select documents for removal from the
cache</description>
-<syntax>MCacheRemovalAlgorithm <code>LRU|GDSF</code></syntax>
+<syntax>MCacheRemovalAlgorithm LRU|GDSF</syntax>
<default>MCacheRemovalAlgorithm GDSF</default>
-<contextlist><context>server config</context><context>virtual host</context>
-</contextlist>
+<contextlist><context>server config</context></contextlist>
<usage>
<p>The <directive>MCacheRemovalAlgorithm</directive> directive specifies
the algorithm used to select documents for removal from the cache.
- Two choices are available:<br />
- <code>LRU</code> (Least Recently Used): <code>LRU</code> removes the
- documents that have not been accessed for the longest time.<br />
- <code>GDSF</code> (GreadyDual-Size): <code>GDSF</code> assigns a priority
- to cached documents based on the cost of a cache miss and the size of
- the document. Documents with the lowest priority are removed first.</p>
-
- <example>
- MCacheRemovalAlgorithm GDSF<br />
- MCacheRemovalAlgorithm LRU<br />
+ Two choices are available:</p>
+
+ <dl>
+ <dt><code>LRU</code> (Least Recently Used)</dt>
+ <dd><code>LRU</code> removes the documents that have not been accessed
+ for the longest time.</dd>
+
+ <dt><code>GDSF</code> (GreadyDual-Size)</dt>
+ <dd><code>GDSF</code> assigns a priority to cached documents based
+ on the cost of a cache miss and the size of the document. Documents
+ with the lowest priority are removed first.</dd>
+ </dl>
+
+ <example><title>Example</title>
+ MCacheRemovalAlgorithm GDSF<br />
+ MCacheRemovalAlgorithm LRU
</example>
</usage>
</directivesynopsis>
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