ngx_http_tcache_module

add the support of memory cache in Tengine

http {
    tcache_shm_zone box size=256M;

    server {
        tcache box;
        tcache_valid 200 1h;

        proxy_pass http://www.example.com;
    }
}

Syntax: tcache_shm_zone name [size=memory_size]

Default: none

Context: http, server, location

Specify the shared memory name and its size. If you don't set the size, by default the memory size is 256M bytes.

Syntax: tcache shm_zone_name

Default: none

Context: http, server, location

Turn on this tcache module. It will store and fetch the HTTP response to and from the shared memory.

Syntax: tcache_key key_string

Default: $scheme$host$uri$is_args$args

Context: http, server, location

The key mapping to the cache file.

Syntax: tcache_valid [status codes] time

Default: none

Context: http, server, location

Set caching time for different response codes. For example, the following directives

tcache_valid 200 302 10m;
tcache_valid 404      1m;

set 10 minutes of caching time for responses with codes 200 and 302, and 1 minute for responses with code 404.

If only caching time is specified

tcache_valid 5m;

then only 200, 301, and 302 responses are cached.

In addition, it can be specified to cache any responses using the any parameter:

tcache_valid 200 302 10m;
tcache_valid 301      1h;
tcache_valid any      1m;

Syntax: tcache_bypass variable ...

Default: none

Context: http, server, location

Define conditions under which the response will not be taken from a cache. If at least one value of the string parameters is not empty and is not equal to “0” then the response will not be taken from the cache:

tcache_bypass $cookie_nocache $arg_nocache$arg_comment;
tcache_bypass $http_pragma    $http_authorization;

Syntax: tcache_no_cache variable ...

Default: none

Context: http, server, location

Define conditions under which the response will not be saved to a cache. If at least one value of the string parameters is not empty and is not equal to “0” then the response will not be saved:

tcache_no_cache $cookie_nocache $arg_nocache$arg_comment;
tcache_no_cache $http_pragma    $http_authorization;

Syntax: tcache_methods methods

Default: GET HEAD

Context: http, server, location

This directive specifies the HTTP request methods are allowed to use the cache, otherwise, the request will be bypassed and not fetch the cache.

The following HTTP methods are allowed: GET, HEAD, POST, PUT, and DELETE. The GET and HEAD methods are always implicitly included in the list regardless of their presence in this directive.

Syntax: tcache_expires time

Default: 60s

Context: http, server, location

Specify the expires time for the cache record. This module will be marked to be expires. And the request will try to fetch a newer version content from origin server.

Syntax: tcache_grace time

Default: 120s

Context: http, server, location

Specify the grace time for the cache record. It should be larger than the expires time. This module will still keep the record in the grace time while it already expires.

Syntax: tcache_use_stale updating | http_500 | http_502 | http_503 | http_504 | http_404 | off

Default: off

Context: http, server, location

If an error occurs while working with the proxied server it is possible to use a stale cached response. This directive determines in which cases it is permitted. The directive’s parameters match the response status code.

Additionally, the updating parameter permits to use a stale cached response if it is currently being updated. This allows to minimize the number of accesses to proxied servers when updating cached data.

Syntax: tcache_hide_header header_name

Default: none

Context: http, server, location

By default, this module caches all the response headers except the following ones:

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

You can hide more response headers (case-insensitive) by means of this directive. For examples,

tcache_hide_header X-Foo;
tcache_hide_header Last-Modified;

Multiple occurrences of this directive are allowed in a single location block.

Syntax: tcache_pass_header header_name

Default: none

Context: http, server, location

You can force this module to store one or more response headers (case-insensitive) by means of this directive. For examples,

tcache_store_pass_header Set-Cookie;
tcache_store_pass_header Proxy-Authenticate;

Multiple occurrences of this directive are allowed in a single location.

Syntax: tcache_store_max_size size

Default: 1M

Context: http, server, location

Specify the maximum size of the cached response. If it's larger than this size, the response will not be cached.

Syntax: tcache_store_buffer_size size

Default: 128K

Context: http, server, location

This module will preallocate an fixed size buffer for storing the response. After it fetches all the response content, this buffer will be copied to the shared memory.