granicus.if.org Git - apache/blob - docs/manual/mod/mod_disk_cache.xml

   1 <?xml version="1.0"?>
   2 <!DOCTYPE modulesynopsis SYSTEM "../style/modulesynopsis.dtd">
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  20
  21 <modulesynopsis metafile="mod_disk_cache.xml.meta">
  22
  23 <name>mod_disk_cache</name>
  24 <description>Content cache storage manager keyed to URIs</description>
  25 <status>Experimental</status>
  26 <sourcefile>mod_disk_cache.c</sourcefile>
  27 <identifier>disk_cache_module</identifier>
  28
  29 <summary>
  30     <note type="warning">
  31       This module is experimental. Documentation is still under development...
  32     </note>
  33
  34     <p><module>mod_disk_cache</module> implements a disk based storage
  35     manager. It is primarily of use in conjunction with
  36     <module>mod_proxy</module>.</p>
  37
  38     <p>Content is stored in and retrieved from the cache using URI based
  39     keys. Content with access protection is not cached.</p>
  40
  41     <note><title>Note:</title>
  42       <p><module>mod_disk_cache</module> requires the services of
  43       <module>mod_cache</module>.</p>
  44     </note>
  45 </summary>
  46
  47 <directivesynopsis>
  48 <name>CacheRoot</name>
  49 <description>The directory root under which cache files are
  50 stored</description>
  51 <syntax>CacheRoot <var>directory</var></syntax>
  52 <contextlist><context>server config</context><context>virtual host</context>
  53 </contextlist>
  54
  55 <usage>
  56     <p>The <directive>CacheRoot</directive> directive defines the name of
  57     the directory on the disk to contain cache files. If the <module
  58     >mod_disk_cache</module> module has been loaded or compiled in to the
  59     Apache server, this directive <em>must</em> be defined. Failing to
  60     provide a value for <directive>CacheRoot</directive> will result in
  61     a configuration file processing error. The <directive
  62     module="mod_disk_cache">CacheDirLevels</directive> and <directive
  63     module="mod_disk_cache">CacheDirLength</directive> directives define
  64     the structure of the directories under the specified root directory.</p>
  65
  66     <example>
  67       CacheRoot c:/cacheroot
  68     </example>
  69 </usage>
  70 </directivesynopsis>
  71
  72 <directivesynopsis>
  73 <name>CacheSize</name>
  74 <description>The maximum amount of disk space that will be used by the
  75 cache in KBytes</description>
  76 <syntax>CacheSize <var>KBytes</var></syntax>
  77 <default>CacheSize 1000000</default>
  78 <contextlist><context>server config</context><context>virtual host</context>
  79 </contextlist>
  80
  81 <usage>
  82     <p>The <directive>CacheSize</directive> directive sets the desired
  83     disk space usage of the cache, in KBytes (1024-byte units). This
  84     directive does not put a  hard limit on the size of the cache. The
  85     garbage collector will delete files until the usage is at or below the
  86     settings. Always use a value that is lower than the available disk
  87     space.</p>
  88
  89     <example>
  90       CacheSize  5000000
  91     </example>
  92 </usage>
  93 </directivesynopsis>
  94
  95 <directivesynopsis>
  96 <name>CacheGcInterval</name>
  97 <description>The interval between garbage collection attempts.</description>
  98 <syntax>CacheGcInterval <var>hours</var></syntax>
  99 <contextlist><context>server config</context><context>virtual host</context>
 100 </contextlist>
 101
 102 <usage>
 103     <p>The <directive>CacheGcInterval</directive> directive specifies the
 104     number of hours to wait between attempts to free up disk space.</p>
 105     <p>More detail will be added here, when the function is implemented.</p>
 106
 107     <example>
 108       CacheGcInterval  24<br />
 109     </example>
 110
 111     <note type="warning">
 112       The <directive>CacheGcInterval</directive> directive is currently
 113       <em>not</em> implemented.
 114     </note>
 115 </usage>
 116 </directivesynopsis>
 117
 118 <directivesynopsis>
 119 <name>CacheDirLevels</name>
 120 <description>The number of levels of subdirectories in the
 121 cache.</description>
 122 <syntax>CacheDirLevels <var>levels</var></syntax>
 123 <default>CacheDirLevels 3</default>
 124 <contextlist><context>server config</context><context>virtual host</context>
 125 </contextlist>
 126
 127 <usage>
 128     <p>The <directive>CacheDirLevels</directive> directive sets the number
 129     of subdirectory levels in the cache. Cached data will be saved this
 130     many directory levels below the <directive module="mod_disk_cache"
 131     >CacheRoot</directive> directory.</p>
 132
 133     <note>
 134       <p>The result of <directive>CacheDirLevels</directive>*
 135       <directive module="mod_disk_cache">CacheDirLength</directive> must
 136       not be higher than 20.</p>
 137     </note>
 138
 139     <example>
 140       CacheDirLevels  5
 141     </example>
 142 </usage>
 143 </directivesynopsis>
 144
 145 <directivesynopsis>
 146 <name>CacheDirLength</name>
 147 <description>The number of characters in subdirectory names</description>
 148 <syntax>CacheDirLength <var>length</var></syntax>
 149 <default>CacheDirLength 2</default>
 150 <contextlist><context>server config</context><context>virtual host</context>
 151 </contextlist>
 152
 153 <usage>
 154     <p>The <directive>CacheDirLength</directive> directive sets the number
 155     of characters for each subdirectory name in the cache hierarchy.</p>
 156
 157     <note>
 158       <p>The result of <directive module="mod_disk_cache"
 159       >CacheDirLevels</directive>* <directive>CacheDirLength</directive>
 160       must not be higher than 20.</p>
 161     </note>
 162
 163     <example>
 164       CacheDirLength  4
 165     </example>
 166 </usage>
 167 </directivesynopsis>
 168
 169 <directivesynopsis>
 170 <name>CacheExpiryCheck</name>
 171 <description>Indicates if the cache observes Expires dates when seeking
 172 files</description>
 173 <syntax>CacheExpiryCheck On|Off</syntax>
 174 <default>CacheExpiryCheck On</default>
 175 <contextlist><context>server config</context><context>virtual host</context>
 176 </contextlist>
 177
 178 <usage>
 179     <p>More detail will be added here, when the function is implemented.</p>
 180
 181     <example>
 182       CacheExpiryCheck Off<br />
 183     </example>
 184
 185     <note type="warning">
 186       The <directive>CacheExpiryCheck</directive> directive is currently
 187       <em>not</em> implemented.
 188     </note>
 189 </usage>
 190 </directivesynopsis>
 191
 192 <directivesynopsis>
 193 <name>CacheMinFileSize</name>
 194 <description>The minimum size (in bytes) of a document to be placed in the
 195 cache</description>
 196 <syntax>CacheMinFileSize <var>bytes</var></syntax>
 197 <default>CacheMinFileSize 1</default>
 198 <contextlist><context>server config</context><context>virtual host</context>
 199 </contextlist>
 200
 201 <usage>
 202     <p>The <directive>CacheMinFileSize</directive> directive sets the
 203     minimum size, in bytes, for a document to be considered for storage
 204     in the cache.</p>
 205
 206     <example>
 207       CacheMinFileSize 64
 208     </example>
 209 </usage>
 210 </directivesynopsis>
 211
 212 <directivesynopsis>
 213 <name>CacheMaxFileSize</name>
 214 <description>The maximum size (in bytes) of a document to be placed in the
 215 cache</description>
 216 <syntax>CacheMaxFileSize <var>bytes</var></syntax>
 217 <default>CacheMaxFileSize 1000000</default>
 218 <contextlist><context>server config</context><context>virtual host</context>
 219 </contextlist>
 220
 221 <usage>
 222     <p>The <directive>CacheMaxFileSize</directive> directive sets the
 223     maximum size, in bytes, for a document to be considered for storage in
 224     the cache.</p>
 225
 226     <example>
 227       CacheMaxFileSize 64000
 228     </example>
 229 </usage>
 230 </directivesynopsis>
 231
 232 <directivesynopsis>
 233 <name>CacheTimeMargin</name>
 234 <description>The minimum time margin to cache a document</description>
 235 <syntax>CacheTimeMargin <var>?</var></syntax>
 236 <default>CacheTimeMargin ?</default>
 237 <contextlist><context>server config</context><context>virtual host</context>
 238 </contextlist>
 239
 240 <usage>
 241     <p>More detail will be added here, when the function is implemented.</p>
 242
 243     <example>
 244       CacheTimeMargin X
 245     </example>
 246
 247     <note type="warning">
 248       The <directive>CacheTimeMargin</directive> directive is currently
 249       <em>not</em> implemented.
 250     </note>
 251 </usage>
 252 </directivesynopsis>
 253
 254 <directivesynopsis>
 255 <name>CacheGcDaily</name>
 256 <description>The recurring time each day for garbage collection to be run.
 257 (24 hour clock)</description>
 258 <syntax>CacheGcDaily <var>time</var></syntax>
 259 <default>CacheGcDaily ?</default>
 260 <contextlist><context>server config</context><context>virtual host</context>
 261 </contextlist>
 262
 263 <usage>
 264     <p>More detail will be added here, when the function is implemented.</p>
 265
 266     <example>
 267       CacheGcDaily 23:59
 268     </example>
 269
 270     <note type="warning">
 271       The <directive>CacheGcDaily</directive> directive is currently
 272       <em>not</em> implemented.
 273     </note>
 274 </usage>
 275 </directivesynopsis>
 276
 277 <directivesynopsis>
 278 <name>CacheGcUnused</name>
 279 <description>The time to retain unreferenced cached files that match a
 280 URL.</description>
 281 <syntax>CacheGcUnused <var>hours</var> <var>url-string</var></syntax>
 282 <default>CacheGcUnused ?</default>
 283 <contextlist><context>server config</context><context>virtual host</context>
 284 </contextlist>
 285
 286 <usage>
 287     <p>More detail will be added here, when the function is implemented.</p>
 288
 289     <example>
 290       CacheGcUnused 12 /local_images
 291     </example>
 292
 293     <note type="warning">
 294       The <directive>CacheGcUnused</directive> directive is currently
 295       <em>not</em> implemented.
 296     </note>
 297 </usage>
 298 </directivesynopsis>
 299
 300 <directivesynopsis>
 301 <name>CacheGcClean</name>
 302 <description>The time to retain unchanged cached files that match a
 303 URL</description>
 304 <syntax>CacheGcClean <var>hours</var> <var>url-string</var></syntax>
 305 <default>CacheGcClean ?</default>
 306 <contextlist><context>server config</context><context>virtual host</context>
 307 </contextlist>
 308
 309 <usage>
 310     <p>More detail will be added here, when the function is implemented.</p>
 311
 312     <example>
 313       CacheGcClean 12 /daily_scripts
 314     </example>
 315
 316     <note type="warning">
 317       The <directive>CacheGcClean</directive> directive is currently
 318       <em>not</em> implemented.
 319     </note>
 320 </usage>
 321 </directivesynopsis>
 322
 323 <directivesynopsis>
 324 <name>CacheGcMemUsage</name>
 325 <description>The maximum kilobytes of memory used for garbage
 326 collection</description>
 327 <syntax>CacheGcMemUsage <var>KBytes</var></syntax>
 328 <default>CacheGcMemUsage ?</default>
 329 <contextlist><context>server config</context><context>virtual host</context>
 330 </contextlist>
 331
 332 <usage>
 333     <p>More detail will be added here, when the function is implemented.</p>
 334
 335     <example>
 336       CacheGcMemUsage 16
 337     </example>
 338
 339     <note type="warning">
 340       The <directive>CacheGcMemUsage</directive> directive is currently
 341       <em>not</em> implemented.
 342     </note>
 343 </usage>
 344 </directivesynopsis>
 345
 346 </modulesynopsis>