Yii2 Redis Laravel Package

Getting Started

Minimal Setup

1. Installation:

   composer require yiisoft/yii2-redis
   

2. Basic Configuration (in config/web.php):

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

3. First Use Case:

   // Cache a value
   Yii::$app->cache->set('key', 'value', 3600);
   
   // Retrieve a value
   $value = Yii::$app->cache->get('key');
   
   // Session usage
   Yii::$app->session->set('user_id', 123);
   $userId = Yii::$app->session->get('user_id');
   

Implementation Patterns

Cache Integration

• Key Naming: Use consistent prefixes (e.g., user:123:profile) to avoid collisions.
• TTL Management: Set appropriate TTLs (e.g., 3600 for 1-hour cache).

  Yii::$app->cache->set('key', $data, 3600);
  

• Cache Invalidation: Clear keys programmatically when data changes.

  Yii::$app->cache->delete('user:123:profile');
  

Session Handling

• Session Data: Store user-specific data (e.g., preferences, cart items).

  Yii::$app->session->set('cart', ['item1', 'item2']);
  

• Flash Messages: Use setFlash() for one-time notifications.

  Yii::$app->session->setFlash('success', 'Item added!');
  

ActiveRecord with Redis

• Model Definition:

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

• CRUD Operations:

  // Create
  $user = new User();
  $user->name = 'John';
  $user->email = 'john@example.com';
  $user->save();
  
  // Read
  $user = User::find()->where(['email' => 'john@example.com'])->one();
  
  // Update
  $user->name = 'John Doe';
  $user->save();
  
  // Delete
  $user->delete();
  

Predis Connection (Advanced)

• Cluster/Sentinel Support:

  'redis' => [
      'class' => 'yii\redis\predis\PredisConnection',
      'parameters' => ['tcp://redis-node-1:6379', 'tcp://redis-node-2:6379'],
  ],
  

• Direct Redis Commands:

  Yii::$app->cache->redis->hset('user:123', 'preferences', ['theme' => 'dark']);
  

Gotchas and Tips

Common Pitfalls

1. Connection Issues:

   • Ensure Redis server is running (redis-cli ping).
   • Check firewall rules if using remote Redis.
   • Debug with Yii::$app->redis->ping() (returns true if connected).

2. Key Expiry:

   • Redis keys expire automatically, but ActiveRecord data persists until manually deleted.
   • Use Yii::$app->cache->delete() to clean up stale data.

3. Predis vs. Native:

   • Predis (PredisConnection) supports clustering but lacks some component features (e.g., Mutex).
   • Native Connection is preferred for full feature support.

Debugging Tips

• Log Redis Commands: Enable Predis logging in config:

  'options' => [
      'logger' => function() {
          return new \Monolog\Logger('redis', [new \Monolog\Handler\StreamHandler('php://stdout')]);
      },
  ],
  

• Check Memory Usage: Monitor Redis memory with redis-cli info memory.

Performance Optimization

• Pipeline Commands: Use Predis pipelines for batch operations:

  $pipeline = Yii::$app->cache->redis->pipeline();
  $pipeline->set('key1', 'value1');
  $pipeline->set('key2', 'value2');
  $pipeline->execute();
  

• Compression: Compress large cached data:

  Yii::$app->cache->set('key', gzcompress($data), 3600);
  

Extension Points

• Custom Cache Tags: Extend Cache to support tags:

  class TaggedCache extends \yii\redis\Cache {
      public function setWithTags($key, $value, $tags = []) {
          $this->set($key, $value);
          foreach ($tags as $tag) {
              $this->redis->sadd("tag:$tag", $key);
          }
      }
  }
  

• Redis Pub/Sub: Use Predis for real-time updates:

  $pubsub = Yii::$app->cache->redis->pubsub();
  $pubsub->subscribe(['channel:updates']);