Redis Cache for WordPress
A persistent cache backend powered by Redis., (*1)
, (*2)
Features
- Enables the two cache wrappers for WordPress
- Adds handy WP-CLI commands
-
wp redis status: Show the Redis cache status and (when possible) client.
-
wp redis flush: Flush the Redis cache, clear all data.
- Supports major PHP Redis drivers
- Supports replication and clustering
- Targets modern software stacks
Installation
-
Prepare your Composer file by adding custom paths (more info), (*3)
{
"extra": {
"dropin-paths": {
"htdocs/wp-content/": [
"package:leocolomb/wp-redis:dropins/object-cache.php",
"package:leocolomb/wp-redis:dropins/advanced-cache.php"
]
}
}
}
-
Require the package in your Composer-managed WordPress instance, (*4)
$ composer require leocolomb/wp-redis
Configuration
To adjust the configuration, define any of the following constants in your wp-config.php file., (*5)
Connection
By default the object cache drop-in will connect to Redis over TCP at 127.0.0.1:6379 and select database 0., (*6)
| Constant name |
Default value |
Description |
WP_REDIS_CLIENT |
not set |
Specifies the client used to communicate with Redis. Supports pecl and predis. |
WP_REDIS_SCHEME |
tcp |
Specifies the protocol used to communicate with an instance of Redis. Internally the client uses the connection class associated to the specified connection scheme. Supports tcp (TCP/IP), unix (UNIX domain sockets), tls (transport layer security) or http (HTTP protocol through Webdis). |
WP_REDIS_HOST |
127.0.0.1 |
IP or hostname of the target server. This is ignored when connecting to Redis using UNIX domain sockets. |
WP_REDIS_PORT |
6379 |
TCP/IP port of the target server. This is ignored when connecting to Redis using UNIX domain sockets. |
WP_REDIS_PATH |
not set |
Path of the UNIX domain socket file used when connecting to Redis using UNIX domain sockets. |
WP_REDIS_DATABASE |
0 |
Accepts a numeric value that is used to automatically select a logical database with the SELECT command. |
WP_REDIS_PASSWORD |
not set |
Accepts a value used to authenticate with a Redis server protected by password with the AUTH command. |
Parameters
| Constant name |
Default value |
Description |
WP_CACHE_KEY_SALT |
not set |
Set the prefix for all cache keys. Useful in setups where multiple installs share a common wp-config.php or $table_prefix, to guarantee uniqueness of cache keys. |
WP_REDIS_MAXTTL |
not set |
Set maximum time-to-live (in seconds) for cache keys with an expiration time of 0. |
WP_REDIS_GLOBAL_GROUPS |
['blog-details', 'blog-id-cache', 'blog-lookup', 'global-posts', 'networks', 'rss', 'sites', 'site-details', 'site-lookup', 'site-options', 'site-transient', 'users', 'useremail', 'userlogins', 'usermeta', 'user_meta', 'userslugs'] |
Set the list of network-wide cache groups that should not be prefixed with the blog-id (Multisite only). |
WP_REDIS_IGNORED_GROUPS |
['counts', 'plugins'] |
Set the cache groups that should not be cached in Redis. |
WP_REDIS_IGBINARY |
not set |
Set to true to enable the igbinary serializer. |
Page cache
| Constant name |
Default value |
Description |
WP_CACHE |
false |
Set to true to enable advanced page caching. If not set, the Redis page cache will not be used. |
WP_REDIS_TIMES |
2 |
Only cache a page after it is accessed this many times. |
WP_REDIS_SECONDS |
120 |
Only cache a page if it is accessed $times in this many seconds. Set to zero to ignore this and use cache immediately. |
WP_REDIS_MAXAGE |
300 |
Expire cache items aged this many seconds. Set to zero to disable cache. |
WP_REDIS_GROUP |
'redis-cache' |
Name of object cache group used for page cache. |
WP_REDIS_UNIQUE |
[] |
If you conditionally serve different content, put the variable values here using the add_variant() method. |
WP_REDIS_HEADERS |
[] |
Add headers here as name => value or name => [values]. These will be sent with every response from the cache. |
WP_REDIS_UNCACHED_HEADERS |
['transfer-encoding'] |
These headers will never be cached. (Use lower case only!) |
WP_REDIS_CACHE_CONTROL |
true |
Set to false to disable Last-Modified and Cache-Control headers. |
WP_REDIS_USE_STALE |
true |
Is it ok to return stale cached response when updating the cache? |
WP_REDIS_NOSKIP_COOKIES |
['wordpress_test_cookie'] |
Names of cookies - if they exist and the cache would normally be bypassed, don't bypass it. |
Replication & Clustering
To use Replication and Clustering, make sure your server is running PHP7, your setup is using Predis to connect to Redis and you consulted the Predis documentation., (*7)
For replication use the WP_REDIS_SERVERS constant and for clustering the WP_REDIS_CLUSTER constant. You can use a named array or an URI string to specify the parameters., (*8)
For authentication use the WP_REDIS_PASSWORD constant., (*9)
Master-Slave Replication
define('WP_REDIS_SERVERS', [
'tcp://127.0.0.1:6379?database=15&alias=master',
'tcp://127.0.0.2:6379?database=15&alias=slave-01',
]);
Clustering via Client-side Sharding
define('WP_REDIS_CLUSTER', [
'tcp://127.0.0.1:6379?database=15&alias=node-01',
'tcp://127.0.0.2:6379?database=15&alias=node-02',
]);
License
GPL-3.0 © Léo Colombaro, (*10)
Wallogit.com
