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slowfs: NGINX SlowFS Cache Module

Installation

You can install this module in any RHEL-based distribution, including, but not limited to:

  • RedHat Enterprise Linux 7, 8, 9
  • CentOS 7, 8, 9
  • AlmaLinux 8, 9
  • Rocky Linux 8, 9
  • Amazon Linux 2 and Amazon Linux 2023
yum -y install https://extras.getpagespeed.com/release-latest.rpm
yum -y install nginx-module-slowfs

Enable the module by adding the following at the top of /etc/nginx/nginx.conf:

load_module modules/ngx_http_slowfs_module.so;

This document describes nginx-module-slowfs v1.11 released on Aug 23 2020.

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 defined 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

See also

GitHub

You may find additional configuration tips and documentation for this module in the GitHub repository for nginx-module-slowfs.