Yii2 Redis Laravel Package

Getting Started

Minimal Setup

1. Install the package:

   composer require yiisoft/yii2-redis:"~2.1.0"
   

2. Configure Redis connection in config/web.php:

   'components' => [
       'redis' => [
           'class' => 'yii\redis\Connection',
           'hostname' => 'localhost',
           'port' => 6379,
           'database' => 0,
       ],
   ],
   

3. First use case: Caching

   Yii::$app->cache->set('key', 'value', 3600); // Cache for 1 hour
   $value = Yii::$app->cache->get('key');
   

Implementation Patterns

Cache Integration

• Replace default cache with Redis:

  'components' => [
      'cache' => [
          'class' => 'yii\redis\Cache',
          'redis' => ['hostname' => 'localhost', 'port' => 6379],
      ],
  ],
  

• Direct Redis commands via $cache->redis:

  Yii::$app->cache->redis->hset('user:1', 'name', 'John Doe');
  

Session Management

• Enable Redis sessions:

  'components' => [
      'session' => [
          'class' => 'yii\redis\Session',
      ],
  ],
  

• Customize session TTL (e.g., 1 day):

  'session' => [
      'class' => 'yii\redis\Session',
      'timeout' => 86400, // 1 day in seconds
  ],
  

ActiveRecord for Redis

• Define a Redis model:

  class User extends \yii\redis\ActiveRecord {
      public function attributes() {
          return ['id', 'username', 'email'];
      }
  }
  

• CRUD operations:

  $user = new User();
  $user->username = 'john';
  $user->save();
  
  $user = User::find()->where(['username' => 'john'])->one();
  

Mutex for Locks

• Lock a critical section:

  $mutex = Yii::$app->redis->getMutex();
  $mutex->acquire(10); // Lock for 10 seconds
  // Critical code here
  $mutex->release();
  

Gotchas and Tips

Pitfalls

1. Connection Failures:

   • Redis may drop connections. Use retry in Predis options:

     'options' => [
         'parameters' => [
             'retry' => new \Predis\Retry\Retry(
                 new \Predis\Retry\Strategy\ExponentialBackoff(1000, 10000),
                 3
             ),
         ],
     ],
     

   • Monitor connection health with Yii::$app->redis->ping().

2. ActiveRecord Limitations:

   • No SQL-like queries (where(), orderBy()). Use find() with scopes:

     User::find()->active()->all(); // Active scope
     

3. Session Expiry:

   • Redis sessions auto-expire after timeout. Ensure timeout is set in config.

Debugging Tips

• Check Redis keys:

  redis-cli KEYS "*"
  

• Log Redis operations for debugging:

  Yii::$app->redis->debug(true);
  

Extension Points

1. Custom Predis Connection: Extend PredisConnection for cluster support:

   'redis' => [
       'class' => 'yii\redis\predis\PredisConnection',
       'parameters' => ['tcp://node1:6379', 'tcp://node2:6379'],
   ],
   

2. Override Cache Behavior: Extend Cache to add custom serialization:

   class CustomRedisCache extends \yii\redis\Cache {
       public function serializeData($data) {
           return json_encode($data);
       }
   }
   

3. Use Redis Pipelining: Batch commands for performance:

   $redis = Yii::$app->redis;
   $redis->pipeline(function ($pipe) {
       $pipe->set('key1', 'value1');
       $pipe->set('key2', 'value2');
   });