CacheDefaultExpire Директива

The CacheDefaultExpire directive specifies a default time, in seconds, to cache a document if neither an expiry date nor last-modified date are provided with the document. The value specified with the CacheMaxExpire directive does not override this setting.

CacheDisable Директива

The CacheDisable directive instructs mod_cache to not cache urls at or below url-string.

The no-cache environment variable can be set to disable caching on a finer grained set of resources in versions 2.2.12 and later.

См также

• Environment Variables in Apache

CacheEnable Директива

The 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.

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.

The no-cache environment variable can be set to disable caching on a finer grained set of resources in versions 2.2.12 and later.

См также

• Environment Variables in Apache

CacheIgnoreCacheControl Директива

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.

См также

• CacheStorePrivate
• CacheStoreNoStore

CacheIgnoreHeaders Директива

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.

CacheIgnoreNoLastMod Директива

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.

CacheIgnoreQueryString Директива

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.

CacheIgnoreURLSessionIdentifiers Директива

Sometimes applications encode the session identifier into the URL like in the following Examples:

• /someapplication/image.gif;jsessionid=123456789
• /someapplication/image.gif?PHPSESSIONID=12345678

This causes cachable resources to be stored separately for each session, which is often not desired. CacheIgnoreURLSessionIdentifiers lets define a list of identifiers that are removed from the key that is used to identify an entity in the cache, such that cachable resources are not stored separately for each session.

CacheIgnoreURLSessionIdentifiers None clears the list of ignored identifiers. Otherwise, each identifier is added to the list.

CacheLastModifiedFactor Директива

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.

CacheMaxExpire Директива

The 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.

CacheStoreNoStore Директива

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.

См также

• CacheIgnoreCacheControl
• CacheStorePrivate

CacheStorePrivate Директива

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.

См также

• CacheIgnoreCacheControl
• CacheStoreNoStore