Introduction
Redis is an open source, advanced key-value store. It is often referred to as a data structure server since keys can contain strings, hashes, lists, sets, and sorted sets.
Before using Redis with Laravel, you will need to install
the predis/predis package via Composer:
composer require predis/predis
Alternatively, you may install the PhpRedis PHP extension via PECL. The extension is more complex to install but may yield better performance for applications that make heavy use of Redis.
Configuration
The Redis configuration for your application is located
in the config/database.php configuration
file. Within this file, you will see a
redis array containing the Redis servers
utilized by your application:
'redis' => [
'client' => 'predis',
'default' => [
'host' => env('REDIS_HOST', 'localhost'),
'password' => env('REDIS_PASSWORD', null),
'port' => env('REDIS_PORT', 6379),
'database' => 0,
],
],
The default server configuration should suffice for development. However, you are free to modify this array based on your environment. Each Redis server defined in your configuration file is required to have a name, host, and port.
Configuring Clusters
If your application is utilizing a cluster of Redis
servers, you should define these clusters within a
clusters key of your Redis
configuration:
'redis' => [
'client' => 'predis',
'clusters' => [
'default' => [
[
'host' => env('REDIS_HOST', 'localhost'),
'password' => env('REDIS_PASSWORD', null),
'port' => env('REDIS_PORT', 6379),
'database' => 0,
],
],
],
],
By default, clusters will perform client-side sharding
across your nodes, allowing you to pool nodes and create
a large amount of available RAM. However, note that
client-side sharding does not handle failover;
therefore, is primarily suited for cached data that is
available from another primary data store. If you would
like to use native Redis clustering, you should specify
this in the options key of your Redis
configuration:
'redis' => [
'client' => 'predis',
'options' => [
'cluster' => 'redis',
],
'clusters' => [
// ...
],
],
Predis
In addition to the default host,
port, database, and
password server configuration options,
Predis supports additional connection
parameters that may be defined for each of your
Redis servers. To utilize these additional configuration
options, simply add them to your Redis server
configuration in the config/database.php
configuration file:
'default' => [
'host' => env('REDIS_HOST', 'localhost'),
'password' => env('REDIS_PASSWORD', null),
'port' => env('REDIS_PORT', 6379),
'database' => 0,
'read_write_timeout' => 60,
],
PhpRedis
Note: If you have the PhpRedis PHP extension installed via PECL, you will need to rename the
Redisalias in yourconfig/app.phpconfiguration file.
To utilize the PhpRedis extension, you should change the
client option of your Redis configuration
to phpredis. This option is found in your
config/database.php configuration file:
'redis' => [
'client' => 'phpredis',
// Rest of Redis configuration...
],
In addition to the default host,
port, database, and
password server configuration options,
PhpRedis supports the following additional connection
parameters: persistent,
prefix, read_timeout and
timeout. You may add any of these options
to your Redis server configuration in the
config/database.php configuration file:
'default' => [
'host' => env('REDIS_HOST', 'localhost'),
'password' => env('REDIS_PASSWORD', null),
'port' => env('REDIS_PORT', 6379),
'database' => 0,
'read_timeout' => 60,
],
Interacting With Redis
You may interact with Redis by calling various methods on
the Redis facade. The
Redis facade supports dynamic methods,
meaning you may call any Redis command on
the facade and the command will be passed directly to
Redis. In this example, we will call the Redis
GET command by calling the get
method on the Redis facade:
<?php
namespace App\Http\Controllers;
use Illuminate\Support\Facades\Redis;
use App\Http\Controllers\Controller;
class UserController extends Controller
{
/**
* Show the profile for the given user.
*
* @param int $id
* @return Response
*/
public function showProfile($id)
{
$user = Redis::get('user:profile:'.$id);
return view('user.profile', ['user' => $user]);
}
}
Of course, as mentioned above, you may call any of the
Redis commands on the Redis facade. Laravel
uses magic methods to pass the commands to the Redis
server, so simply pass the arguments the Redis command
expects:
Redis::set('name', 'Taylor');
$values = Redis::lrange('names', 5, 10);
Alternatively, you may also pass commands to the server
using the command method, which accepts the
name of the command as its first argument, and an array
of values as its second argument:
$values = Redis::command('lrange', ['name', 5, 10]);
Using Multiple Redis Connections
You may get a Redis instance by calling the
Redis::connection method:
$redis = Redis::connection();
This will give you an instance of the default Redis
server. You may also pass the connection or cluster name
to the connection method to get a specific
server or cluster as defined in your Redis
configuration:
$redis = Redis::connection('my-connection');
Pipelining Commands
Pipelining should be used when you need to send many
commands to the server in one operation. The
pipeline method accepts one argument: a
Closure that receives a Redis instance. You
may issue all of your commands to this Redis instance
and they will all be executed within a single
operation:
Redis::pipeline(function ($pipe) {
for ($i = 0; $i < 1000; $i ) {
$pipe->set("key:$i", $i);
}
});
Pub / Sub
Laravel provides a convenient interface to the Redis
publish and subscribe
commands. These Redis commands allow you to listen for
messages on a given "channel". You may publish
messages to the channel from another application, or
even using another programming language, allowing easy
communication between applications and processes.
First, let's setup a channel listener using the
subscribe method. We'll place this method
call within an Artisan
command since calling the subscribe
method begins a long-running process:
<?php
namespace App\Console\Commands;
use Illuminate\Console\Command;
use Illuminate\Support\Facades\Redis;
class RedisSubscribe extends Command
{
/**
* The name and signature of the console command.
*
* @var string
*/
protected $signature = 'redis:subscribe';
/**
* The console command description.
*
* @var string
*/
protected $description = 'Subscribe to a Redis channel';
/**
* Execute the console command.
*
* @return mixed
*/
public function handle()
{
Redis::subscribe(['test-channel'], function ($message) {
echo $message;
});
}
}
Now we may publish messages to the channel using the
publish method:
Route::get('publish', function () {
// Route logic...
Redis::publish('test-channel', json_encode(['foo' => 'bar']));
});
Wildcard Subscriptions
Using the psubscribe method, you may
subscribe to a wildcard channel, which may be useful for
catching all messages on all channels. The
$channel name will be passed as the second
argument to the provided callback
Closure:
Redis::psubscribe(['*'], function ($message, $channel) {
echo $message;
});
Redis::psubscribe(['users.*'], function ($message, $channel) {
echo $message;
});