mod_disk_cache Content cache storage manager keyed to URIs Extension mod_disk_cache.c disk_cache_module

mod_disk_cache implements a disk based storage manager. It is primarily of use in conjunction with mod_cache.

Content is stored in and retrieved from the cache using URI based keys. Content with access protection is not cached.

htcacheclean can be used to maintain the cache size at a maximum level.

Note:

mod_disk_cache requires the services of mod_cache.

 Note:

mod_disk_cache uses the sendfile feature to serve files from the cache when supported by the platform, and when enabled with EnableSendfile. However, per-directory and .htaccess configuration of EnableSendfile are ignored by mod_disk_cache as the corresponding settings are not available to the module when a request is being served from the cache.

 CacheRoot The directory root under which cache files are stored CacheRoot directory server configvirtual host

The CacheRoot directive defines the name of the directory on the disk to contain cache files. If the mod_disk_cache module has been loaded or compiled in to the Apache server, this directive must be defined. Failing to provide a value for CacheRoot will result in a configuration file processing error. The CacheDirLevels and CacheDirLength directives define the structure of the directories under the specified root directory.

CacheRoot c:/cacheroot CacheDirLevels The number of levels of subdirectories in the cache. CacheDirLevels levels CacheDirLevels 2 server configvirtual host

The CacheDirLevels directive sets the number of subdirectory levels in the cache. Cached data will be saved this many directory levels below the CacheRoot directory.

A high value for CacheDirLevels combined with a low value for CacheDirLength will result in a relatively deep hierarchy, with a small number of subdirectories at each level.

The result of CacheDirLevels* CacheDirLength must not be higher than 20.

 CacheDirLength The number of characters in subdirectory names CacheDirLength length CacheDirLength 2 server configvirtual host

The CacheDirLength directive sets the number of characters for each subdirectory name in the cache hierarchy. It can be used in conjunction with CacheDirLevels to determine the approximate structure of your cache hierarchy.

A high value for CacheDirLength combined with a low value for CacheDirLevels will result in a relatively flat hierarchy, with a large number of subdirectories at each level.

The result of CacheDirLevels* CacheDirLength must not be higher than 20.

 CacheMinFileSize The minimum size (in bytes) of a document to be placed in the cache CacheMinFileSize bytes CacheMinFileSize 1 server configvirtual host

The CacheMinFileSize directive sets the minimum size, in bytes, for a document to be considered for storage in the cache.

CacheMinFileSize 64 CacheMaxFileSize The maximum size (in bytes) of a document to be placed in the cache CacheMaxFileSize bytes CacheMaxFileSize 1000000 server configvirtual host

The CacheMaxFileSize directive sets the maximum size, in bytes, for a document to be considered for storage in the cache.

CacheMaxFileSize 64000 CacheReadSize The minimum size (in bytes) of the document to read and be cached before sending the data downstream CacheReadSize bytes CacheReadSize 0 server config virtual host directory .htaccess

The CacheReadSize directive sets the minimum amount of data, in bytes, to be read from the backend before the data is sent to the client. The default of zero causes all data read of any size to be passed downstream to the client immediately as it arrives. Setting this to a higher value causes the disk cache to buffer at least this amount before sending the result to the client. This can improve performance when caching content from a reverse proxy.

This directive only takes effect when the data is being saved to the cache, as opposed to data being served from the cache.

CacheReadSize 102400 CacheReadTime The minimum time (in milliseconds) that should elapse while reading before data is sent downstream CacheReadTime milliseconds CacheReadTime 0 server config virtual host directory .htaccess

The CacheReadTime directive sets the minimum amount of elapsed time that should pass before making an attempt to send data downstream to the client. During the time period, data will be buffered before sending the result to the client. This can improve performance when caching content from a reverse proxy.

The default of zero disables this option.

This directive only takes effect when the data is being saved to the cache, as opposed to data being served from the cache. It is recommended that this option be used alongside the CacheReadSize directive to ensure that the server does not buffer excessively should data arrive faster than expected.

CacheReadTime 1000