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 (~1.0) via Composer.
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
used by your application:
'redis' => [
'cluster' => false,
'default' => [
'host' => '127.0.0.1',
'port' => 6379,
'database' => 0,
],
],
The default server configuration should suffice for development. However, you are free to modify this array based on your environment. Simply give each Redis server a name, and specify the host and port used by the server.
The cluster
option will tell the Laravel Redis client to
perform client-side sharding across your Redis 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.
Additionally, you may define an options
array value in
your Redis connection definition, allowing you to specify a set of
Predis client
options.
If your Redis server requires authentication, you may supply a
password by adding a password
configuration item to your
Redis server configuration array.
Note: If you have the Redis PHP extension installed via PECL, you will need to rename the alias for Redis in your
config/app.php
file.
Basic Usage
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 GET
command on Redis by calling the
get
method on the Redis
facade:
<?php
namespace App\Http\Controllers;
use 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. If you
are not using server clustering, you may pass the server name to the
connection
method to get a specific server as defined in
your Redis configuration:
$redis = Redis::connection('other');
Pipelining Commands
Pipelining should be used when you need to send many commands to the
server in one operation. The pipeline
method accepts one
argument: a Closure
that receives a Redis instance. You may
issue all of your commands to this Redis instance and they will all be
executed within a single operation:
Redis::pipeline(function ($pipe) {
for ($i = 0; $i < 1000; $i++) {
$pipe->set("key:$i", $i);
}
});
Pub / Sub
Laravel also 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 / processes.
First, let's setup a listener on a channel via Redis using the
subscribe
method. We will place this method call within an
Artisan command since calling the
subscribe
method begins a long-running process:
<?php
namespace App\Console\Commands;
use Redis;
use Illuminate\Console\Command;
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 is 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;
});