About

ngx_slowfs_cache is nginx module which allows caching of static files (served using root directive). This enables one to create fast caches for files stored on slow filesystems, for example:

• storage: network disks, cache: local disks,
• storage: 7,2K SATA drives, cache: 15K SAS drives in RAID0.

WARNING! There is no point in using this module when cache is placed on the same speed disk(s) as origin.

Sponsors

ngx_slowfs_cache was fully funded by c2hosting.com.

Status

This module is production-ready and it's compatible with following nginx releases:

• 0.7.x (tested with 0.7.60 to 0.7.69),
• 0.8.x (tested with 0.8.0 to 0.8.55),
• 0.9.x (tested with 0.9.0 to 0.9.7),
• 1.0.x (tested with 1.0.0 to 1.0.15),
• 1.1.x (tested with 1.1.0 to 1.1.19),
• 1.2.x (tested with 1.2.0 to 1.2.7),
• 1.3.x (tested with 1.3.0 to 1.3.14).

Configuration notes

slowfs_cache_path and slowfs_temp_path values should point to the same filesystem, otherwise files will be copied twice.

ngx_slowfs_cache currently doesn't work when AIO is enabled.

Configuration directives

slowfs_cache

• syntax: slowfs_cache zone_name
• default: none
• context: http, server, location

Sets area used for caching (previously definied using slowfs_cache_path).

slowfs_cache_key

• syntax: slowfs_cache_key key
• default: none
• context: http, server, location

Sets key for caching.

slowfs_cache_purge

• syntax: slowfs_cache_purge zone_name key
• default: none
• context: location

Sets area and key used for purging selected pages from cache.

slowfs_cache_path

• syntax: slowfs_cache_path path [levels] keys_zone=zone_name:zone_size [inactive] [max_size]
• default: none
• context: http

Sets cache area and its structure.

slowfs_temp_path

• syntax: slowfs_temp_path path [level1] [level2] [level3]
• default: /tmp 1 2
• context: http

Sets temporary area where files are stored before they are moved to cache area.

slowfs_cache_min_uses

• syntax: slowfs_cache_min_uses number
• default: 1
• context: http, server, location

Sets number of uses after which file is copied to cache.

slowfs_cache_valid

• syntax: slowfs_cache_valid [reply_code] time
• default: none
• context: http, server, location

Sets time for which file will be served from cache.

slowfs_big_file_size

• syntax: slowfs_big_file_size size
• default: 128k
• context: http, server, location

Sets minimum file size for big files. Worker processes fork() child process before they start copying big files to avoid any service disruption.

Configuration variables

$slowfs_cache_status

Represents availability of cached file.

Possible values are: MISS, HIT and EXPIRED.

Sample configuration

http {
    slowfs_cache_path  /tmp/cache levels=1:2 keys_zone=fastcache:10m;
    slowfs_temp_path   /tmp/temp 1 2;

    server {
        location / {
            root                /var/www;
            slowfs_cache        fastcache;
            slowfs_cache_key    $uri;
            slowfs_cache_valid  1d;
        }

        location ~ /purge(/.*) {
            allow               127.0.0.1;
            deny                all;
            slowfs_cache_purge  fastcache $1;
        }
   }
}

Testing

ngx_slowfs_cache comes with complete test suite based on Test::Nginx.

You can test it by running:

$ prove

License

Copyright (c) 2009-2012, FRiCKLE <info@frickle.com>
Copyright (c) 2009-2012, Piotr Sikora <piotr.sikora@frickle.com>
Copyrithg (c) 2002-2012, Igor Sysoev <igor@sysoev.ru>
All rights reserved.

This project was fully funded by c2hosting.com.
Included cache_purge functionality was fully funded by yo.se.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
   notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
   notice, this list of conditions and the following disclaimer in the
   documentation and/or other materials provided with the distribution.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

See also

• ngx_cache_purge.