### Basic Redis Configuration Example

Source: https://github.com/rhubarbgroup/redis-cache/wiki/Home

This example shows a basic configuration for connecting to a Redis server. Ensure these definitions are placed before 'wp-settings.php' in your wp-config.php file.

```php
define( 'WP_REDIS_HOST', '127.0.0.1' );
define( 'WP_REDIS_PORT', 6379 );
// define( 'WP_REDIS_PASSWORD', 'secret' );
define( 'WP_REDIS_TIMEOUT', 1 );
define( 'WP_REDIS_READ_TIMEOUT', 1 );

// change the database for each site to avoid cache collisions
define( 'WP_REDIS_DATABASE', 0 );

// supported clients: `phpredis`, `credis`, `predis` and `hhvm`
// define( 'WP_REDIS_CLIENT', 'phpredis' );

// automatically delete cache keys after 7 days
// define( 'WP_REDIS_MAXTTL', 60 * 60 * 24 * 7 );

// bypass the object cache, useful for debugging
// define( 'WP_REDIS_DISABLED', true );
```

--------------------------------

### Sharding Mode: Start 3 Redis Instances

Source: https://github.com/rhubarbgroup/redis-cache/wiki/Docker-Development

Starts 3 Redis instances in sharding mode. The default client used is predis.

```bash
./docker/start.sh shard
```

--------------------------------

### Replication Mode: Start Master and Slaves

Source: https://github.com/rhubarbgroup/redis-cache/wiki/Docker-Development

Starts 4 Redis containers (1 master, 3 slaves) in replication mode. The default client used is phpredis.

```bash
./docker/start.sh replication
```

--------------------------------

### Cluster Mode: Start 3 Redis Instances

Source: https://github.com/rhubarbgroup/redis-cache/wiki/Docker-Development

Starts 3 Redis instances in cluster mode. The default client used is predis.

```bash
./docker/start.sh cluster
```

--------------------------------

### Default Usage: Start Single Redis Container

Source: https://github.com/rhubarbgroup/redis-cache/wiki/Docker-Development

Starts a single Redis container for the simplest mode of operation. The default client used is phpredis.

```bash
./docker/start.sh
```

--------------------------------

### Sentinel Mode: Start Sentinels and Replicated Redis

Source: https://github.com/rhubarbgroup/redis-cache/wiki/Docker-Development

Starts 3 sentinel instances and 6 normal Redis containers (1 master, 5 slaves) in replication mode. The default client used is predis.

```bash
./docker/start.sh sentinel
```

--------------------------------

### Install Predis using Composer

Source: https://github.com/rhubarbgroup/redis-cache/blob/develop/dependencies/predis/predis/README.md

Use Composer to add Predis as a project dependency.

```shell
composer require predis/predis
```

--------------------------------

### Basic Redis Cluster Setup

Source: https://github.com/rhubarbgroup/redis-cache/blob/develop/dependencies/colinmollenhour/credis/README.markdown

Initialize Credis_Cluster for utilizing Redis cluster scalability. Requires the phpredis extension. Pass a cluster name or seed nodes.

```php
<?php
require 'Credis/Client.php';
require 'Credis/Cluster.php';

$cluster = new Credis_Cluster(
    null, // $clusterName // Optional. Name from redis.ini. See https://github.com/phpredis/phpredis/blob/develop/cluster.md 
    ['redis-node-1:6379', 'redis-node-2:6379', 'redis-node-3:6379'], // $clusterSeeds // don't need all nodes, as it pulls that info from one randomly
    null, // $timeout
    null, // $readTimeout
    false, //$persistentBool
    'TopSecretPassword', // $password
    null, //$username
    null //$tlsOptions
);
$cluster->set('key','value');
echo "Get: ".$cluster->get('key').PHP_EOL;
```

--------------------------------

### Install and Configure Redis Cache via Composer

Source: https://github.com/rhubarbgroup/redis-cache/blob/develop/INSTALL.md

Use Composer to install the Redis Object Cache plugin, enable the drop-in, check its status, and configure connection parameters using wp-cli.

```bash
# Install the plugin:
composer require wpackagist-plugin/redis-cache

# Next, enable the drop-in:
wp redis enable

# Check the connection:
wp redis status

# Configure the plugin
wp config set WP_REDIS_HOST "127.0.0.1"
wp config set WP_REDIS_PORT "6379"
wp config set WP_REDIS_DATABASE "15"
```

--------------------------------

### Predis Sentinel Configuration with Authentication and Database

Source: https://github.com/rhubarbgroup/redis-cache/blob/develop/dependencies/predis/predis/README.md

Example of Predis Sentinel configuration including password authentication and specifying a different database index. These are passed via the 'parameters' client option.

```php
$options = [
    'replication' => 'sentinel',
    'service' => 'mymaster',
    'parameters' => [
        'password' => $secretpassword,
        'database' => 10,
    ],
];
```

--------------------------------

### Configure Redis Cluster

Source: https://github.com/rhubarbgroup/redis-cache/blob/develop/README.md

Configure a Redis Cluster setup using the 'phpredis' client. This defines the nodes participating in the cluster.

```php
define( 'WP_REDIS_CLIENT', 'phpredis' );

define( 'WP_REDIS_CLUSTER', [
    'tcp://127.0.0.1:6379?alias=node-01',
    'tcp://127.0.0.2:6379?alias=node-02',
    'tcp://127.0.0.3:6379?alias=node-03',
] );
```

--------------------------------

### Configure Redis Connection Parameters

Source: https://github.com/rhubarbgroup/redis-cache/wiki/Connection-Parameters

Define these constants in your wp-config.php to customize Redis connection settings. This example shows explicit settings for host, port, password, timeouts, database, client, max TTL, and disabling the cache.

```php
define( 'WP_REDIS_HOST', '127.0.0.1' );
define( 'WP_REDIS_PORT', 6379 );
// define( 'WP_REDIS_PASSWORD', 'secret' );
define( 'WP_REDIS_TIMEOUT', 1 );
define( 'WP_REDIS_READ_TIMEOUT', 1 );

// change the database for each site to avoid cache collisions
// values 0-15 are valid in a default redis config.
define( 'WP_REDIS_DATABASE', 0 );

// supported clients: `phpredis`, `credis`, `predis` and `hhvm`
// define( 'WP_REDIS_CLIENT', 'phpredis' );

// automatically delete cache keys after 7 days
// define( 'WP_REDIS_MAXTTL', 60 * 60 * 24 * 7 );

// bypass the object cache, useful for debugging
// define( 'WP_REDIS_DISABLED', true );
```

--------------------------------

### Credis Contribution: Code Formatting

Source: https://github.com/rhubarbgroup/redis-cache/blob/develop/dependencies/colinmollenhour/credis/README.markdown

Commands to install the PHP-CS-Fixer tool and format the project code according to coding standards.

```shell
composer require "friendsofphp/php-cs-fixer:^3.13" --dev --no-update -n
composer format
```

--------------------------------

### Configure Relay Client

Source: https://github.com/rhubarbgroup/redis-cache/blob/develop/README.md

Set the client to 'relay' for advanced caching that keeps a partial replica of Redis' dataset in PHP's memory. Each WordPress installation requires a dedicated Redis database and unique prefix when using Relay.

```php
define( 'WP_REDIS_CLIENT', 'relay' );

define( 'WP_REDIS_HOST', '127.0.0.1' );
define( 'WP_REDIS_PORT', 6379 );

// when using Relay, each WordPress installation
// MUST a dedicated Redis database and unique prefix
define( 'WP_REDIS_DATABASE', 0 );
define( 'WP_REDIS_PREFIX', 'db3:' );

// consume less memory
define( 'WP_REDIS_IGBINARY', true );
```

--------------------------------

### Check Redis Server Connection

Source: https://github.com/rhubarbgroup/redis-cache/blob/develop/FAQ.md

Use redis-cli to verify if the Redis server is running and accessible. This command is useful for initial setup and troubleshooting connection issues.

```bash
redis-cli PING
```

```bash
redis-cli -h 127.0.0.1 -p 6379 PING
```

--------------------------------

### Activate Redis Cache Plugin

Source: https://github.com/rhubarbgroup/redis-cache/wiki/WP-CLI-Commands

Activates the Redis object cache plugin using WP-CLI. Ensure the plugin is installed before activation.

```bash
wp plugin activate redis-cache
```

--------------------------------

### Open Redis-CLI on Second Redis Slave Instance

Source: https://github.com/rhubarbgroup/redis-cache/wiki/Docker-Development

Connects to the second Redis slave instance using redis-cli. The index might vary based on the Docker Compose setup.

```bash
docker-compose exec --index=2 redis-slave redis-cli
```

--------------------------------

### redis_object_cache_get

Source: https://github.com/rhubarbgroup/redis-cache/wiki/Hooks-&-Actions

Fires on every cache get request.

```APIDOC
## redis_object_cache_get

### Description
Fires on every cache get request.

### Parameters
* _`mixed`_ `$value` Value of the cache entry.
* _`string`_ `$key` The cache key.
* _`string`_ `$group` The group value appended to the $key.
* _`bool`_ `$force` Whether a forced refetch has taken place rather than relying on the local cache.
* _`bool`_ `$found` Whether the key was found in the cache.
* _`float`_ `$execute_time` Execution time for the request in seconds.
```

--------------------------------

### redis_object_cache_get_multiple

Source: https://github.com/rhubarbgroup/redis-cache/wiki/Hooks-&-Actions

Fires on every cache get multiple request.

```APIDOC
## redis_object_cache_get_multiple

### Description
Fires on every cache get multiple request.

### Parameters
* _`mixed`_ `$value` Value of the cache entry.
* _`string`_ `$key` The cache key.
* _`string`_ `$group` The group value appended to the $key.
* _`bool`_ `$force` Whether a forced refetch has taken place rather than relying on the local cache.
* _`float`_ `$execute_time` Execution time for the request in seconds.
```

--------------------------------

### Flush Redis Server Data

Source: https://github.com/rhubarbgroup/redis-cache/blob/develop/FAQ.md

Execute FLUSHALL command to clear all data from the Redis server. This is necessary when multiple WordPress installations share the same Redis database index, causing domain redirection issues.

```bash
redis-cli -h 127.0.01 -p 6379 FLUSHALL
```

--------------------------------

### Stop All Docker Containers

Source: https://github.com/rhubarbgroup/redis-cache/wiki/Docker-Development

Stops all running Docker containers. Add the -v flag to delete all persistent data and start clean next time.

```bash
./docker/start.sh down
```

--------------------------------

### Basic Client Configuration with Prefix

Source: https://github.com/rhubarbgroup/redis-cache/blob/develop/dependencies/predis/predis/README.md

Instantiates a Predis client with a specified key prefix. This option is useful for namespacing keys in Redis.

```php
$client = new Predis\Client($parameters, ['prefix' => 'sample:']);
```

--------------------------------

### Execute Predis Pipeline with Fluent Interface

Source: https://github.com/rhubarbgroup/redis-cache/blob/develop/dependencies/predis/predis/README.md

Demonstrates using Predis pipelines with a fluent interface, allowing commands to be chained before execution. This provides a more readable way to construct pipelines.

```php
$responses = $client->pipeline()->set('foo', 'bar')->get('foo')->execute();
```

--------------------------------

### Configure Predis for Master/Slave Replication

Source: https://github.com/rhubarbgroup/redis-cache/blob/develop/dependencies/predis/predis/README.md

Sets up a Predis client with a static list of master and slave servers for replication. The master is explicitly defined, while slaves are optional.

```php
$parameters = ['tcp://10.0.0.1?role=master', 'tcp://10.0.0.2', 'tcp://10.0.0.3'];
$options    = ['replication' => 'predis'];

$client = new Predis\Client($parameters, $options);
```

--------------------------------

### Configure Redis Replication (Sentinel)

Source: https://github.com/rhubarbgroup/redis-cache/wiki/Replication-&-Clustering

For Sentinel-based replication, define `WP_REDIS_SENTINEL` with the Sentinel alias and `WP_REDIS_SERVERS` with the Sentinel host addresses. Ensure `WP_REDIS_CLIENT` is set to 'predis'.

```php
define( 'WP_REDIS_CLIENT', 'predis' );
define( 'WP_REDIS_SENTINEL', 'my-sentinel' );
define( 'WP_REDIS_SERVERS', [
    'tcp://127.0.0.1:5380',
    'tcp://127.0.0.2:5381',
    'tcp://127.0.0.3:5382',
] );
```

--------------------------------

### Connect to Redis with Default Parameters

Source: https://github.com/rhubarbgroup/redis-cache/blob/develop/dependencies/predis/predis/README.md

Instantiate a Predis client without parameters to connect to localhost on the default port (6379).

```php
$client = new Predis\Client();
$client->set('foo', 'bar');
$value = $client->get('foo');
```

--------------------------------

### Basic Credis Client Initialization

Source: https://github.com/rhubarbgroup/redis-cache/blob/develop/dependencies/colinmollenhour/credis/README.markdown

Instantiate the Credis_Client with a connection string. Supports Unix socket, TCP, and TLS connections.

```php
$redis = new Credis_Client(/* connection string */);
```

--------------------------------

### Configure Replication

Source: https://github.com/rhubarbgroup/redis-cache/blob/develop/README.md

Set up Redis replication using the 'predis' client. This configuration defines master and replica servers for high availability.

```php
define( 'WP_REDIS_CLIENT', 'predis' );

define( 'WP_REDIS_SERVERS', [
    'tcp://127.0.0.1:6379?database=5&role=master',
    'tcp://127.0.0.2:6379?database=5&alias=replica-01',
] );
```

--------------------------------

### Implement Custom Connection Backend

Source: https://github.com/rhubarbgroup/redis-cache/blob/develop/dependencies/predis/predis/README.md

Create custom connection classes implementing Predis\Connection\NodeConnectionInterface or extending Predis\Connection\AbstractConnection to support new network backends.

```php
class MyConnectionClass implements Predis\Connection\NodeConnectionInterface
{
    // Implementation goes here...
}

// Use MyConnectionClass to handle connections for the `tcp` scheme:
$client = new Predis\Client('tcp://127.0.0.1', [
    'connections' => ['tcp' => 'MyConnectionClass'],
]);
```

--------------------------------

### Configure Redis Sentinel

Source: https://github.com/rhubarbgroup/redis-cache/blob/develop/README.md

Set up Redis Sentinel for high availability using the 'predis' client. Specify the Sentinel master name and server addresses.

```php
define( 'WP_REDIS_CLIENT', 'predis' );

define( 'WP_REDIS_SENTINEL', 'my-sentinel' );
define( 'WP_REDIS_SERVERS', [
    'tcp://127.0.0.1:5380',
    'tcp://127.0.0.2:5381',
    'tcp://127.0.0.3:5382',
] );
```

--------------------------------

### Open Redis-CLI on Master Instance

Source: https://github.com/rhubarbgroup/redis-cache/wiki/Docker-Development

Connects to the Redis master instance using redis-cli.

```bash
docker-compose exec redis-master redis-cli
```

--------------------------------

### Configure Relay Connection Backend

Source: https://github.com/rhubarbgroup/redis-cache/blob/develop/dependencies/predis/predis/README.md

Use the Relay integration for performance gains by caching a partial replica of the Redis dataset in PHP shared runtime memory.

```php
$client = new Predis\Client('tcp://127.0.0.1', [
    'connections' => 'relay',
]);
```

--------------------------------

### Cluster Configuration (Client-Side Sharding)

Source: https://github.com/rhubarbgroup/redis-cache/blob/develop/dependencies/predis/predis/README.md

Configures Predis to work with a cluster using traditional client-side sharding. Requires manual rebalancing of the keyspace.

```php
$parameters = ['tcp://10.0.0.1', 'tcp://10.0.0.2', 'tcp://10.0.0.3'];
$options    = ['cluster' => 'predis'];

$client = new Predis\Client($parameters);
```

--------------------------------

### Configure Redis Replication (Master-Replica)

Source: https://github.com/rhubarbgroup/redis-cache/wiki/Replication-&-Clustering

Use the `WP_REDIS_SERVERS` constant to define master and replica servers for replication. Ensure `WP_REDIS_CLIENT` is set to 'predis'.

```php
define( 'WP_REDIS_CLIENT', 'predis' );
define( 'WP_REDIS_SERVERS', [
    'tcp://127.0.0.1:6379?database=5&alias=master',
    'tcp://127.0.0.2:6379?database=5&alias=replica-01',
] );
```

--------------------------------

### Basic Credis Client Usage

Source: https://github.com/rhubarbgroup/redis-cache/blob/develop/dependencies/colinmollenhour/credis/README.markdown

Instantiate a Credis_Client, set a key-value pair, and retrieve the value. Demonstrates automatic flattening of array arguments for commands like RPUSH.

```php
require 'Credis/Client.php';
$redis = new Credis_Client('localhost');
$redis->set('awesome', 'absolutely');
echo sprintf('Is Credis awesome? %s.\n', $redis->get('awesome'));

// When arrays are given as arguments they are flattened automatically
$redis->rpush('particles', array('proton','electron','neutron'));
$particles = $redis->lrange('particles', 0, -1);
```

--------------------------------

### Connect with TLS/SSL Encryption (Array)

Source: https://github.com/rhubarbgroup/redis-cache/blob/develop/dependencies/predis/predis/README.md

Enable TLS/SSL encryption for secure connections by using the 'tls' scheme and providing SSL options.

```php
$client = new Predis\Client([
  'scheme' => 'tls',
  'ssl'    => ['cafile' => 'private.pem', 'verify_peer' => true],
]);
```

--------------------------------

### Configure Redis Connection in wp-config.php

Source: https://github.com/rhubarbgroup/redis-cache/blob/develop/INSTALL.md

Define constants in wp-config.php to configure the Redis host, port, prefix, database, and timeouts. Ensure these constants are defined before the wp-settings.php file is included.

```php
// adjust Redis host and port if necessary 
define( 'WP_REDIS_HOST', '127.0.0.1' );
define( 'WP_REDIS_PORT', 6379 );

// change the prefix and database for each site to avoid cache data collisions
define( 'WP_REDIS_PREFIX', 'my-moms-site' );
define( 'WP_REDIS_DATABASE', 0 ); // 0-15

// reasonable connection and read+write timeouts
define( 'WP_REDIS_TIMEOUT', 1 );
define( 'WP_REDIS_READ_TIMEOUT', 1 );
```

```php
/* That's all, stop editing! Happy publishing. */
require_once(ABSPATH . 'wp-settings.php');
```

--------------------------------

### Connect with TLS/SSL Encryption (URI)

Source: https://github.com/rhubarbgroup/redis-cache/blob/develop/dependencies/predis/predis/README.md

Enable TLS/SSL encryption using a URI string, specifying SSL options within the query parameters.

```php
$client = new Predis\Client('tls://127.0.0.1?ssl[cafile]=private.pem&ssl[verify_peer]=1');
```

--------------------------------

### Execute Predis Pipeline within a Callable Block

Source: https://github.com/rhubarbgroup/redis-cache/blob/develop/dependencies/predis/predis/README.md

Shows how to execute a series of commands as a pipeline within a callable block. This reduces network latency by sending multiple commands at once.

```php
$responses = $client->pipeline(function ($pipe) {
    for ($i = 0; $i < 1000; $i++) {
        $pipe->set("key:". $i, str_pad($i, 4, '0', 0));
        $pipe->get("key:". $i);
    }
});
```

--------------------------------

### Custom Replication Strategy for EVAL/EVALSHA Scripts

Source: https://github.com/rhubarbgroup/redis-cache/blob/develop/dependencies/predis/predis/README.md

Demonstrates how to customize replication behavior for EVAL and EVALSHA commands. A custom strategy can be used to specify which Lua scripts are safe to execute on slaves, preventing unnecessary switches to the master.

```php
$parameters = ['tcp://10.0.0.1?role=master', 'tcp://10.0.0.2', 'tcp://10.0.0.3'];
$options    = ['replication' => function () {
    // Set scripts that won't trigger a switch from a slave to the master node.
    $strategy = new Predis\Replication\ReplicationStrategy();
    $strategy->setScriptReadOnly($LUA_SCRIPT);

    return new Predis\Connection\Replication\MasterSlaveReplication($strategy);
}];

$client = new Predis\Client($parameters, $options);
$client->eval($LUA_SCRIPT, 0);             // Sticks to slave using `eval`...
$client->evalsha(sha1($LUA_SCRIPT), 0);    // ... and `evalsha`, too.
```

--------------------------------

### Open Redis-CLI on First Redis Sentinel Instance

Source: https://github.com/rhubarbgroup/redis-cache/wiki/Docker-Development

Connects to the first Redis sentinel instance using redis-cli on port 26379.

```bash
docker-compose exec --index=1 redis-sentinel redis-cli -p 26379
```

--------------------------------

### Connect using UNIX Domain Sockets (Array)

Source: https://github.com/rhubarbgroup/redis-cache/blob/develop/dependencies/predis/predis/README.md

Connect to a local Redis instance using a UNIX domain socket by specifying the 'unix' scheme and the socket path.

```php
$client = new Predis\Client(['scheme' => 'unix', 'path' => '/path/to/redis.sock']);
```

--------------------------------

### Connect to Redis using URI String

Source: https://github.com/rhubarbgroup/redis-cache/blob/develop/dependencies/predis/predis/README.md

Provide connection parameters as a URI string. This is an alternative to using named arrays.

```php
$client = new Predis\Client('tcp://10.0.0.1:6379');
```

--------------------------------

### Configure TLS/SSL Stream Options

Source: https://github.com/rhubarbgroup/redis-cache/blob/develop/README.md

Define additional TLS/SSL stream connection options for secure connections. This can be used to customize peer verification.

```php
define( 'WP_REDIS_SSL_CONTEXT', [
    'verify_peer' => false,
    'verify_peer_name' => false,
]);
```

--------------------------------

### wp redis enable

Source: https://github.com/rhubarbgroup/redis-cache/wiki/WP-CLI-Commands

Enables the Redis object cache by creating the object cache drop-in. This command respects existing unknown drop-ins.

```APIDOC
## wp redis enable

### Description
Enables the Redis object cache. Default behavior is to create the object cache drop-in, unless an unknown object cache drop-in is present.

### Method
CLI command

### Endpoint
wp redis enable

### Parameters
None

### Response
Confirmation of Redis object cache enablement.
```

--------------------------------

### Connect to Redis using Named Array Parameters

Source: https://github.com/rhubarbgroup/redis-cache/blob/develop/dependencies/predis/predis/README.md

Specify connection parameters like scheme, host, and port using a PHP associative array.

```php
$client = new Predis\Client([
    'scheme' => 'tcp',
    'host'   => '10.0.0.1',
    'port'   => 6379,
]);
```

--------------------------------

### Set Maximum Cache Key Time-To-Live

Source: https://github.com/rhubarbgroup/redis-cache/wiki/Configuration-Options

Configure the maximum time-to-live in seconds for cache keys that have an expiration time of 0.

```php
define( 'WP_REDIS_MAXTTL', 86400 );
```

--------------------------------

### Connect using UNIX Domain Sockets (URI)

Source: https://github.com/rhubarbgroup/redis-cache/blob/develop/dependencies/predis/predis/README.md

Connect to a local Redis instance using a UNIX domain socket via a URI string with the 'unix' scheme.

```php
$client = new Predis\Client('unix:/path/to/redis.sock');
```

--------------------------------

### Configure Test Environment Variables

Source: https://github.com/rhubarbgroup/redis-cache/wiki/Local-Development

Create a `config.sh` file to override default test environment variables. This is optional if default values are acceptable.

```bash
GIT_BRANCH=trunk # the wordpress version you want to test against
DB_HOST=127.0.0.1
DB_PASS=mysuperpassword # your password, default empty
DB_NAME=yourdatabase # your database name, default `wp_tests`
DB_USER=youruser # your database user, default `root`
```

--------------------------------

### Execute Raw Redis Commands

Source: https://github.com/rhubarbgroup/redis-cache/blob/develop/dependencies/predis/predis/README.md

Send raw Redis commands to the server without argument filtering or response parsing. Arguments must be provided as an array.

```php
$response = $client->executeRaw(['SET', 'foo', 'bar']);
```

--------------------------------

### Configure Redis Client

Source: https://github.com/rhubarbgroup/redis-cache/wiki/Configuration-Options

Specify the client used for Redis communication. Supported options are 'phpredis', 'predis', and 'relay'.

```php
define( 'WP_REDIS_CLIENT', 'predis' );
```

--------------------------------

### Configure Predis with Redis Sentinel for HA

Source: https://github.com/rhubarbgroup/redis-cache/blob/develop/dependencies/predis/predis/README.md

Configures a Predis client to use Redis Sentinel for high availability. This requires a list of sentinel connection parameters, replication set to 'sentinel', and the service name.

```php
$sentinels = ['tcp://10.0.0.1', 'tcp://10.0.0.2', 'tcp://10.0.0.3'];
$options   = ['replication' => 'sentinel', 'service' => 'mymaster'];

$client = new Predis\Client($sentinels, $options);
```

--------------------------------

### Configure Redis Serializer

Source: https://github.com/rhubarbgroup/redis-cache/wiki/Configuration-Options

Use PhpRedis' built-in serializers. Supported values are Redis::SERIALIZER_PHP and Redis::SERIALIZER_IGBINARY.

```php
define( 'WP_REDIS_SERIALIZER', Redis::SERIALIZER_IGBINARY );
```

--------------------------------

### Connect via Unix Socket

Source: https://github.com/rhubarbgroup/redis-cache/blob/develop/README.md

Use this configuration to connect to Redis using a Unix domain socket. Ensure the socket path is correct.

```php
define( 'WP_REDIS_SCHEME', 'unix' );
define( 'WP_REDIS_PATH', '/var/run/redis.sock' );
```

--------------------------------

### Connect via TCP with TLS

Source: https://github.com/rhubarbgroup/redis-cache/blob/develop/README.md

Configure TCP connection with TLS encryption. Specify the host and port for your Redis instance.

```php
define( 'WP_REDIS_SCHEME', 'tls' );
define( 'WP_REDIS_HOST', 'master.ncit.ameaqx.use1.cache.amazonaws.com' );
define( 'WP_REDIS_PORT', 6379 );
```

--------------------------------

### Configure Redis Sharding

Source: https://github.com/rhubarbgroup/redis-cache/wiki/Replication-&-Clustering

Use the `WP_REDIS_SHARDS` constant to define multiple Redis servers for sharding. Each server can be configured with a database and an alias.

```php
define( 'WP_REDIS_SHARDS', [
    'tcp://127.0.0.1:6379?database=10&alias=shard-01',
    'tcp://127.0.0.2:6379?database=10&alias=shard-02',
    'tcp://127.0.0.3:6379?database=10&alias=shard-03',
] );
```

--------------------------------

### Configure Redis Clustering (Redis 3.0+)

Source: https://github.com/rhubarbgroup/redis-cache/wiki/Replication-&-Clustering

For Redis 3.0 and later, use the `WP_REDIS_CLUSTER` constant to define the nodes in your Redis cluster. Each node can be configured with an alias.

```php
define( 'WP_REDIS_CLUSTER', [
    'tcp://127.0.0.1:6379?alias=node-01',
    'tcp://127.0.0.2:6379?alias=node-02',
    'tcp://127.0.0.3:6379?alias=node-03',
] );
```

--------------------------------

### Define Default Global Cache Groups

Source: https://github.com/rhubarbgroup/redis-cache/wiki/Configuration-Options

Set the list of network-wide cache groups that should not be prefixed with the blog-id. This is applicable only in a Multisite environment.

```php
define( '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',
] );
```

--------------------------------

### Enable Redis Object Cache

Source: https://github.com/rhubarbgroup/redis-cache/wiki/WP-CLI-Commands

Enables the Redis object cache by creating the object cache drop-in file. This command will overwrite an existing drop-in if it's not recognized.

```bash
wp redis enable
```

--------------------------------

### Configure Sharding with PhpRedis

Source: https://github.com/rhubarbgroup/redis-cache/blob/develop/README.md

Configure sharding using PhpRedis' RedisArray feature. This distributes data across multiple Redis instances.

```php
define( 'WP_REDIS_CLIENT', 'phpredis' );

define( 'WP_REDIS_SHARDS', [
    'tcp://127.0.0.1:6379?database=10&alias=shard-01',
    'tcp://127.0.0.2:6379?database=10&alias=shard-02',
    'tcp://127.0.0.3:6379?database=10&alias=shard-03',
] );
```

--------------------------------

### Set Redis Socket Path

Source: https://github.com/rhubarbgroup/redis-cache/wiki/Configuration-Options

Define the path to the Redis socket file if using a Unix domain socket.

```php
define( 'WP_REDIS_PATH', '/var/run/redis/redis-server.sock' );
```

--------------------------------

### Define and Inject Lua Script Commands

Source: https://github.com/rhubarbgroup/redis-cache/blob/develop/dependencies/predis/predis/README.md

Extend Predis\Command\ScriptCommand to define Lua scripts for remote execution. Scripts are identified by SHA1 hash for efficiency.

```php
class ListPushRandomValue extends Predis\Command\ScriptCommand
{
    public function getKeysCount()
    {
        return 1;
    }

    public function getScript()
    {
        return <<<LUA
math.randomseed(ARGV[1])
local rnd = tostring(math.random())
redis.call('lpush', KEYS[1], rnd)
return rnd
LUA;
    }
}
```

```php
$client = new Predis\Client($parameters, [
    'commands' => [
        'lpushrand' => 'ListPushRandomValue',
    ],
]);

$response = $client->lpushrand('random_values', $seed = mt_rand());
```

--------------------------------

### Enable igbinary Serializer

Source: https://github.com/rhubarbgroup/redis-cache/wiki/Configuration-Options

Set to true to enable the igbinary serializer. This setting is ignored if WP_REDIS_SERIALIZER is already defined.

```php
define( 'WP_REDIS_IGBINARY', true );
```

--------------------------------

### Define and Inject Custom Redis Commands

Source: https://github.com/rhubarbgroup/redis-cache/blob/develop/dependencies/predis/predis/README.md

Extend Predis\Command\Command to define new Redis commands or override existing ones. Inject custom commands into the client's command factory.

```php
class BrandNewRedisCommand extends Predis\Command\Command
{
    public function getId()
    {
        return 'NEWCMD';
    }
}
```

```php
$client = new Predis\Client($parameters, [
    'commands' => [
        'newcmd' => 'BrandNewRedisCommand',
    ],
]);

$response = $client->newcmd();
```

--------------------------------

### Register Predis Autoloader

Source: https://github.com/rhubarbgroup/redis-cache/blob/develop/dependencies/predis/predis/README.md

Manually register Predis's autoloader if not using Composer. Ensure the Predis path is in your include_path.

```php
// Prepend a base path if Predis is not available in your "include_path".
require 'Predis/Autoloader.php';

Predis\Autoloader::register();
```

--------------------------------

### Aggregate Multiple Connections

Source: https://github.com/rhubarbgroup/redis-cache/blob/develop/dependencies/predis/predis/README.md

Configure Predis to aggregate multiple Redis connections for clustering or replication, mixing array and URI configurations.

```php
$client = new Predis\Client([
    'tcp://10.0.0.1?alias=first-node', ['host' => '10.0.0.2', 'alias' => 'second-node'],
], [
    'cluster' => 'predis',
]);
```

--------------------------------

### Connect to Redis with TLS

Source: https://github.com/rhubarbgroup/redis-cache/blob/develop/dependencies/colinmollenhour/credis/README.markdown

Enables transport level security by using a 'tls://' connection string. This is recommended over plain TCP for secure communication.

```php
require 'Credis/Client.php';
$redis = new Credis_Client('tls://127.0.0.1:6379');
$redis->set('awesome', 'absolutely');
echo sprintf('Is Credis awesome? %s.\n', $redis->get('awesome'));

// When arrays are given as arguments they are flattened automatically
$redis->rpush('particles', array('proton','electron','neutron'));
$particles = $redis->lrange('particles', 0, -1);
```

--------------------------------

### redis_object_cache_enable

Source: https://github.com/rhubarbgroup/redis-cache/wiki/Hooks-&-Actions

Fires on cache enabling event.

```APIDOC
## redis_object_cache_enable

### Description
Fires on cache enabling event.

### Parameters
* _`bool`_ `$result` Whether the filesystem event was successfull.
```

--------------------------------

### Enter WordPress Container Bash Shell

Source: https://github.com/rhubarbgroup/redis-cache/wiki/Docker-Development

Executes a bash shell inside the WordPress container for interactive use.

```bash
docker-compose exec wordpress bash
```

--------------------------------

### Connect to Password-Protected Redis

Source: https://github.com/rhubarbgroup/redis-cache/blob/develop/dependencies/predis/predis/README.md

Connect to Redis servers that require a password for authentication. For Redis >= 6.0 with ACLs, username is also required.

```php
// Example for password protection (username omitted if not needed):
// $client = new Predis\Client(['host' => '10.0.0.1', 'password' => 'your_password']);
// Example for Redis >= 6.0 with ACLs:
// $client = new Predis\Client(['host' => '10.0.0.1', 'username' => 'your_username', 'password' => 'your_password']);
```

--------------------------------

### Redis Cluster Configuration (Coordinated)

Source: https://github.com/rhubarbgroup/redis-cache/blob/develop/dependencies/predis/predis/README.md

Connects to a Redis Cluster managed by redis-cluster. The client automatically discovers nodes and handles redirection.

```php
$parameters = ['tcp://10.0.0.1', 'tcp://10.0.0.2', 'tcp://10.0.0.3'];
$options    = ['cluster' => 'redis'];

$client = new Predis\Client($parameters, $options);
```

--------------------------------

### Set Metrics Collection Timeframe

Source: https://github.com/rhubarbgroup/redis-cache/wiki/Configuration-Options

Define the maximum timeframe in seconds for collecting object cache metrics. Increase this value with caution.

```php
define( 'WP_REDIS_METRICS_MAX_TIME', 7200 );
```

--------------------------------

### Delete All Transients with WP-CLI

Source: https://github.com/rhubarbgroup/redis-cache/blob/develop/FAQ.md

Use this WP-CLI command to clear all transients stored in the database before enabling Redis. This ensures that Redis will be used for new transients.

```bash
wp transient delete-all
```

--------------------------------

### redis_object_cache_update_dropin

Source: https://github.com/rhubarbgroup/redis-cache/wiki/Hooks-&-Actions

Fires on dropin update event.

```APIDOC
## redis_object_cache_update_dropin

### Description
Fires on dropin update event.

### Parameters
* _`bool`_ `$result` Whether the filesystem event was successfull.
```

--------------------------------

### Debug Redis Cache Flushes in PHP

Source: https://github.com/rhubarbgroup/redis-cache/blob/develop/FAQ.md

Use this action hook to log detailed information about cache flush events. Check the generated log file to identify plugins causing frequent flushes.

```php
add_action( 'redis_object_cache_flush', function( $results ) {
    ob_start();
    echo date( 'c' ) . PHP_EOL;
    var_dump( $results );
    debug_print_backtrace();
    error_log( ob_get_clean(), 3, ABSPATH . '/redis-cache-flush.log' );
}, 10, 5 );
```

--------------------------------

### Connect with ACL Authentication

Source: https://github.com/rhubarbgroup/redis-cache/blob/develop/README.md

Configure ACL authentication for Redis by providing a username and password. This is used for enhanced security.

```php
define( 'WP_REDIS_PASSWORD', [ 'username', 'password' ] );
```

--------------------------------

### redis_object_cache_set

Source: https://github.com/rhubarbgroup/redis-cache/wiki/Hooks-&-Actions

Fires on every cache set.

```APIDOC
## redis_object_cache_set

### Description
Fires on every cache set.

### Parameters
* _`string`_ `$key` The cache key.
* _`mixed`_ `$value` Value of the cache entry.
* _`string`_ `$group` The group value appended to the $key.
* _`int`_ `$expiration` The time in seconds the entry expires. 0 for no expiry.
* _`float`_ `$execute_time` Execution time for the request in seconds.
```

--------------------------------

### Enable Selective Cache Flushing

Source: https://github.com/rhubarbgroup/redis-cache/wiki/Configuration-Options

When set to true, cache flushing will only remove keys prefixed with WP_REDIS_PREFIX, rather than emptying the entire Redis database.

```php
define( 'WP_REDIS_SELECTIVE_FLUSH', true );
```

--------------------------------

### redis_object_cache_error

Source: https://github.com/rhubarbgroup/redis-cache/wiki/Hooks-&-Actions

Fires on every cache error.

```APIDOC
## redis_object_cache_error

### Description
Fires on every cache error.

### Parameters
* _`\Exception`_ `$exception` The exception triggered.
```

--------------------------------

### redis_object_cache_flush

Source: https://github.com/rhubarbgroup/redis-cache/wiki/Hooks-&-Actions

Fires on every cache flush.

```APIDOC
## redis_object_cache_flush

### Description
Fires on every cache flush.

### Parameters
* _`null|array`_ `$results` Array of flush results.
* _`int`_ `$delay` Given number of seconds to waited before invalidating the items.
* _`bool`_ `$seletive` Whether a selective flush took place.
* _`string`_ `$salt` The defined key prefix.
* _`float`_ `$execute_time` Execution time for the request in seconds.
```

--------------------------------

### wp redis update-dropin

Source: https://github.com/rhubarbgroup/redis-cache/wiki/WP-CLI-Commands

Updates the Redis object cache drop-in, overwriting any existing drop-in by default.

```APIDOC
## wp redis update-dropin

### Description
Updates the Redis object cache drop-in. Default behavior is to overwrite any existing object cache drop-in.

### Method
CLI command

### Endpoint
wp redis update-dropin

### Parameters
None

### Response
Confirmation of the object cache drop-in update.
```

--------------------------------

### Set Unflushable Cache Groups

Source: https://github.com/rhubarbgroup/redis-cache/wiki/Configuration-Options

Specify cache groups that should not be flushed during a selective cache flush operation.

```php
define( 'WP_REDIS_UNFLUSHABLE_GROUPS', ['do-not-flush-me'] );
```

--------------------------------

### Disable Graceful Failures

Source: https://github.com/rhubarbgroup/redis-cache/wiki/Configuration-Options

Set to false to disable graceful failures and allow exceptions to be thrown when the cache encounters issues.

```php
define( 'WP_REDIS_GRACEFUL', false );
```

--------------------------------

### Execute Redis Transactions

Source: https://github.com/rhubarbgroup/redis-cache/blob/develop/dependencies/predis/predis/README.md

Execute Redis transactions using a callable block or a fluent interface. Supports automatic retries for aborted transactions.

```php
$responses = $client->transaction(function ($tx) {
    $tx->set('foo', 'bar');
    $tx->get('foo');
});
```

```php
$responses = $client->transaction()->set('foo', 'bar')->get('foo')->execute();
```

--------------------------------

### Disable Admin Banners

Source: https://github.com/rhubarbgroup/redis-cache/wiki/Configuration-Options

Set to true to hide administrative banners and notices that promote Object Cache Pro. This does not affect the settings screen.

```php
define( 'WP_REDIS_DISABLE_BANNERS', true );
```

--------------------------------

### wp redis status

Source: https://github.com/rhubarbgroup/redis-cache/wiki/WP-CLI-Commands

Shows the current status of the Redis object cache and, if available, the connected client.

```APIDOC
## wp redis status

### Description
Show the Redis object cache status and (when possible) client.

### Method
CLI command

### Endpoint
wp redis status

### Parameters
None

### Response
Status of the Redis object cache and client information.
```

--------------------------------

### Set Ignored Cache Groups

Source: https://github.com/rhubarbgroup/redis-cache/wiki/Configuration-Options

Define cache groups that should not be cached in Redis. Defaults to ['counts', 'plugins'].

```php
define( 'WP_REDIS_IGNORED_GROUPS', ['counts', 'plugins'] );
```

--------------------------------

### redis_object_cache_delete

Source: https://github.com/rhubarbgroup/redis-cache/wiki/Hooks-&-Actions

Fires on every cache key deletion.

```APIDOC
## redis_object_cache_delete

### Description
Fires on every cache key deletion.

### Parameters
* _`string`_ `$key` The cache key.
* _`string`_ `$group` The group value appended to the $key.
* _`float`_ `$execute_time` Execution time for the request in seconds.
```

--------------------------------

### redis_object_cache_disable

Source: https://github.com/rhubarbgroup/redis-cache/wiki/Hooks-&-Actions

Fires on cache disabling event.

```APIDOC
## redis_object_cache_disable

### Description
Fires on cache disabling event.

### Parameters
* _`bool`_ `$result` Whether the filesystem event was successfull.
```

--------------------------------

### Diagnose Frequent Cache Flushes

Source: https://github.com/rhubarbgroup/redis-cache/wiki/Troubleshooting

Use this snippet to log the callstack of every cache flush. This helps identify plugins or processes causing excessive cache invalidation. Do not use in production.

```php
add_action( 'redis_object_cache_flush', function( $results, $delay, $selective, $salt, $execute_time ) {
  ob_start();
  echo date( 'c' ) . PHP_EOL;
  debug_print_backtrace();
  var_dump( func_get_args() );
  error_log( ABSPATH . '/redis-cache-flush.log', 3, ob_get_clean() );
}, 10, 5 );
```