Apache HTTP Server 版本2.2
说明 | 基于URI键的内容动态缓冲(内存或磁盘) |
---|---|
状态 | 扩展(E) |
模块名 | cache_module |
源文件 | mod_cache.c |
mod_cache
实现了一个RFC 2616兼容的HTTP本地缓存或HTTP代理缓存。mod_cache
需要一个或多个存储管理模块提供的服务才能正常工作。目前官方发布的存储管理模块有两个:
mod_disk_cache
mod_mem_cache
mod_mem_cache
可以被配置为两种不同的操作模式:①缓存打开的文件描述符;②在堆(heap)上缓存对象。mod_mem_cache
既可以用于缓存本地生成的内容,也可以用于为反向代理模式下的mod_proxy
(参见ProxyPass
)缓存后端服务器输出的内容。内容将被以基于URI的索引存入和检出,但是并不保存相应的访问控制信息。
更多的细节、讨论、实例,可以参考缓冲指南。
相关模块 | 相关指令 |
---|---|
#
# 缓存示范配置
#
LoadModule cache_module modules/mod_cache.so
<IfModule mod_cache.c>
#LoadModule disk_cache_module modules/mod_disk_cache.so
# 如果你想使用mod_disk_cache代替mod_mem_cache的话,
# 那么就取消上面的注释,并将下面的LoadModule行加上注释
<IfModule mod_disk_cache.c>
CacheRoot c:/cacheroot
CacheEnable disk /
CacheDirLevels 5
CacheDirLength 3
</IfModule>
LoadModule mem_cache_module modules/mod_mem_cache.so
<IfModule mod_mem_cache.c>
CacheEnable mem /
MCacheSize 4096
MCacheMaxObjectCount 100
MCacheMinObjectSize 1
MCacheMaxObjectSize 2048
</IfModule>
# 在充当代理的时候,不缓存update-list下的内容
CacheDisable http://security.update.server/update-list/
</IfModule>
说明 | 默认缓存有效期(秒) |
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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 |
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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。
CacheDisable /local_files
说明 | 使用特定的存储类型缓存某些特定的URL |
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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 https://www.apache.org/
说明 | Ignore request to not serve cached content to client |
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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
说明 | Do not store the given HTTP header(s) in the cache. |
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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
.
CacheIgnoreHeaders Set-Cookie
CacheIgnoreHeaders None
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. |
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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. |
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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 |
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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. |
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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
说明 | Attempt to cache responses that the server has marked as private |
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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