HTTP Redis

Description

You can use this module to perform simple caching. There are plans to extend this module in the near future. Latest version available at http://people.FreeBSD.org/~osa/ngx_http_redis-0.3.8.tar.gz.

Starting from nginx 1.9.11, it’s possible to compile this module as a dynamic module, by using the --add-dynamic-module=PATH option instead of --add-module=PATH on the ./configure command line. Then it’s possible to explicitly load the module in a nginx.conf via the load_module (http://nginx.org/en/docs/ngx_core_module.html#load_module) directive:

load_module /path/to/modules/ngx_http_redis_module.so;

Example configuration

server {
    location / {
        set $redis_key $uri;

        redis_pass     name:6379;
        default_type   text/html;
        error_page     404 = /fallback;
    }

    location = /fallback {
        proxy_pass backend;
    }
}

Directives

redis_pass

Syntax:redis_pass [name:port]
Default:none
Context:http, server, location

The backend should set the data in redis. The redis key is /uri?args.

redis_bind

Syntax:redis_bind [addr]
Default:none
Context:http, server, localtion

Use the following IP address as the source address for redis connections.

redis_connect_timeout

Syntax:redis_connect_timeout [time]
Default:60000
Context:http, server, location

The timeout for connecting to redis, in milliseconds.

redis_read_timeout

Syntax:redis_read_timeout [time]
Default:60000
Context:http, server, location

The timeout for reading from redis, in milliseconds.

redis_send_timeout

Syntax:redis_send_timeout [time]
Default:60000
Context:http, server, location

The timeout for sending to redis, in milliseconds.

redis_buffer_size

Syntax:redis_buffer_size [size]
Default:see getpagesize(2)
Context:http, server, location

The recv/send buffer size, in bytes.

redis_next_upstream

Syntax:redis_next_upstream [error] [timeout] [invalid_response] [not_found] [off]
Default:error timeout
Context:http, server, location

Which failure conditions should cause the request to be forwarded to another upstream server? Applies only when the value in redis_pass is an upstream with two or more servers.

redis_gzip_flag

Syntax:redis_gzip_flag [number]
Default:unset
Context:location

Reimplementation of memcached_gzip_flag, see http://forum.nginx.org/read.php?29,34332,34463 for details.

Variables

$redis_key

The value of the redis key.

$redis_db

The number of redis database (required for < 0.3.4).

For ngx_http_redis >= 0.3.4 is not obligatory, default value is 0 if not defined.

Keep-alive connections to redis servers

In 0.3.5 support of keep-alive connection backported from original ngx_http_memcached module of NGINX 1.1.4. For previous versions of NGINX you should use following instruction.

You need Maxim Dounin’s third party ngx_upstream_keepalive module together with this module for keep-alive TCP connections to your backend redis servers.

Here’s a sample configuration:

http {
    upstream redisbackend {
        server 127.0.0.1:6379;

        # a pool with at most 1024 connections
        # and do not distinguish the servers:
        keepalive 1024 single;
    }

    server {
        ...
        location /redis {
            ...
            redis_pass redisbackend;
        }
    }
}

Support

Please use author’s email address for submit bug reports, patches and fixes.

Author

Sergey A. Osokin <osa@FreeBSD.ORG.ru>

See also

  • Redis2 that implements almost the whole Redis 2.0 protocol.
  • SR Cache that can be used with this module to do transparent response caching for arbitrary NGINX locations.
  • The lua-resty-redis library for Lua.