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 either 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',
'cluster' => false,
'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.
The cluster
option will instruct 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.
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
Redis
alias in yourconfig/app.php
configuration 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. 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 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;
});