说明 默认缓存有效期(秒) 语法 CacheDefaultExpire seconds 默认值 CacheDefaultExpire 3600 (一小时) 作用域 server config, virtual host 状态 扩展(E) 模块 mod_cache

CacheDefaultExpire指令设置了那些既没有包含"Expires"或"Cache-Control"头，也没有包含"Last-Modified"头的缓存对象的默认有效期(按秒计)。CacheMaxExpire指令的值并不会覆盖这里的设置。

CacheDefaultExpire 86400

说明 禁止缓存某些特定的URL 语法 CacheDisable url-string 作用域 server config, virtual host 状态 扩展(E) 模块 mod_cache

CacheDisable指令表示禁止缓存url-string自身以及所有以url-string开头的URL。

示例

CacheDisable /local_files

说明 使用特定的存储类型缓存某些特定的URL 语法 CacheEnable cache_type url-string 作用域 server config, virtual host 状态 扩展(E) 模块 mod_cache

CacheEnable directive instructs mod_cache to cache urls at or below url-string. The cache storage manager is specified with the cache_type argument. cache_type mem instructs mod_cache to use the memory based storage manager implemented by mod_mem_cache. cache_type disk instructs mod_cache to use the disk based storage manager implemented by mod_disk_cache. cache_type fd instructs mod_cache to use the file descriptor cache implemented by mod_mem_cache.

In the event that the URL space overlaps between different CacheEnable directives (as in the example below), each possible storage manager will be run until the first one that actually processes the request. The order in which the storage managers are run is determined by the order of the CacheEnable directives in the configuration file.

CacheEnable mem /manual
CacheEnable fd /images
CacheEnable disk /


When acting as a forward proxy server, url-string can also be used to specify remote sites and proxy protocols which caching should be enabled for.

# Cache proxied url's
CacheEnable disk /

# Cache FTP-proxied url's
CacheEnable disk ftp://

# Cache content from www.apache.org
CacheEnable disk http://www.apache.org/


说明 Ignore request to not serve cached content to client 语法 CacheIgnoreCacheControl On|Off 默认值 CacheIgnoreCacheControl Off 作用域 server config, virtual host 状态 扩展(E) 模块 mod_cache

Ordinarily, requests containing a Cache-Control: no-cache or Pragma: no-cache header value will not be served from the cache. The CacheIgnoreCacheControl directive allows this behavior to be overridden. CacheIgnoreCacheControl On tells the server to attempt to serve the resource from the cache even if the request contains no-cache header values. Resources requiring authorization will never be cached.

CacheIgnoreCacheControl On

Warning:

This directive will allow serving from the cache even if the client has requested that the document not be served from the cache. This might result in stale content being served.

参见

• CacheStorePrivate
• CacheStoreNoStore

说明 Do not store the given HTTP header(s) in the cache. 语法 CacheIgnoreHeaders header-string [header-string] ... 默认值 CacheIgnoreHeaders None 作用域 server config, virtual host 状态 扩展(E) 模块 mod_cache

According to RFC 2616, hop-by-hop HTTP headers are not stored in the cache. The following HTTP headers are hop-by-hop headers and thus do not get stored in the cache in any case regardless of the setting of CacheIgnoreHeaders:

• Connection
• Keep-Alive
• Proxy-Authenticate
• Proxy-Authorization
• TE
• Trailers
• Transfer-Encoding
• Upgrade

CacheIgnoreHeaders specifies additional HTTP headers that should not to be stored in the cache. For example, it makes sense in some cases to prevent cookies from being stored in the cache.

CacheIgnoreHeaders takes a space separated list of HTTP headers that should not be stored in the cache. If only hop-by-hop headers not should be stored in the cache (the RFC 2616 compliant behaviour), CacheIgnoreHeaders can be set to None.

Example 1

CacheIgnoreHeaders Set-Cookie

Example 2

CacheIgnoreHeaders None

Warning:

If headers like Expires which are needed for proper cache management are not stored due to a CacheIgnoreHeaders setting, the behaviour of mod_cache is undefined.

说明 Ignore the fact that a response has no Last Modified header. 语法 CacheIgnoreNoLastMod On|Off 默认值 CacheIgnoreNoLastMod Off 作用域 server config, virtual host 状态 扩展(E) 模块 mod_cache

Ordinarily, documents without a last-modified date are not cached. Under some circumstances the last-modified date is removed (during mod_include processing for example) or not provided at all. The CacheIgnoreNoLastMod directive provides a way to specify that documents without last-modified dates should be considered for caching, even without a last-modified date. If neither a last-modified date nor an expiry date are provided with the document then the value specified by the CacheDefaultExpire directive will be used to generate an expiration date.

CacheIgnoreNoLastMod On

说明 Ignore query string when caching 语法 CacheIgnoreQueryString On|Off 默认值 CacheIgnoreQueryString Off 作用域 server config, virtual host 状态 Extension 模块 mod_cache 兼容性 Available in Apache 2.2.6 and later

Ordinarily, requests with query string parameters are cached separately for each unique query string. This is according to RFC 2616/13.9 done only if an expiration time is specified. The CacheIgnoreQueryString directive tells the cache to cache requests even if no expiration time is specified, and to reply with a cached reply even if the query string differs. From a caching point of view the request is treated as if having no query string when this directive is enabled.

CacheIgnoreQueryString On

说明 The factor used to compute an expiry date based on the LastModified date. 语法 CacheLastModifiedFactor float 默认值 CacheLastModifiedFactor 0.1 作用域 server config, virtual host 状态 扩展(E) 模块 mod_cache

In the event that a document does not provide an expiry date but does provide a last-modified date, an expiry date can be calculated based on the time since the document was last modified. The CacheLastModifiedFactor directive specifies a factor to be used in the generation of this expiry date according to the following formula: expiry-period = time-since-last-modified-date * factor expiry-date = current-date + expiry-period For example, if the document was last modified 10 hours ago, and factor is 0.1 then the expiry-period will be set to 10*0.1 = 1 hour. If the current time was 3:00pm then the computed expiry-date would be 3:00pm + 1hour = 4:00pm. If the expiry-period would be longer than that set by CacheMaxExpire, then the latter takes precedence.

CacheLastModifiedFactor 0.5

说明 The maximum time in seconds to cache a document 语法 CacheMaxExpire seconds 默认值 CacheMaxExpire 86400 (one day) 作用域 server config, virtual host 状态 扩展(E) 模块 mod_cache

CacheMaxExpire directive specifies the maximum number of seconds for which cachable HTTP documents will be retained without checking the origin server. Thus, documents will be out of date at most this number of seconds. This maximum value is enforced even if an expiry date was supplied with the document.

CacheMaxExpire 604800

说明 Attempt to cache requests or responses that have been marked as no-store. 语法 CacheStoreNoStore On|Off 默认值 CacheStoreNoStore Off 作用域 server config, virtual host 状态 扩展(E) 模块 mod_cache

Ordinarily, requests or responses with Cache-Control: no-store header values will not be stored in the cache. The CacheStoreNoCache directive allows this behavior to be overridden. CacheStoreNoCache On tells the server to attempt to cache the resource even if it contains no-store header values. Resources requiring authorization will never be cached.

CacheStoreNoStore On

Warning:

As described in RFC 2616, the no-store directive is intended to "prevent the inadvertent release or retention of sensitive information (for example, on backup tapes)." Enabling this option could store sensitive information in the cache. You are hereby warned.

参见

• CacheIgnoreCacheControl
• CacheStorePrivate

说明 Attempt to cache responses that the server has marked as private 语法 CacheStorePrivate On|Off 默认值 CacheStorePrivate Off 作用域 server config, virtual host 状态 扩展(E) 模块 mod_cache

Ordinarily, responses with Cache-Control: private header values will not be stored in the cache. The CacheStorePrivate directive allows this behavior to be overridden. CacheStorePrivate On tells the server to attempt to cache the resource even if it contains private header values. Resources requiring authorization will never be cached.

CacheStorePrivate On

Warning:

This directive will allow caching even if the upstream server has requested that the resource not be cached. This directive is only ideal for a 'private' cache.

参见

• CacheIgnoreCacheControl
• CacheStoreNoStore