Memcached Bundle Laravel Package

Getting Started

Minimal Setup

1. Installation Add the bundle via Composer:

   composer require besimple/memcached-bundle
   

   Register the bundle in config/bundles.php:

   return [
       // ...
       BeSimple\MemcachedBundle\BeSimpleMemcachedBundle::class => ['all' => true],
   ];
   

2. Configuration Define Memcached servers in config/packages/besimple_memcached.yaml:

   besimple_memcached:
       servers:
           - host: '127.0.0.1'
             port: 11211
             weight: 1
       options:
           prefix: 'myapp_'
           compression: true
   

3. First Use Case Inject the MemcachedClient service into a controller or service:

   use BeSimple\MemcachedBundle\Client\MemcachedClientInterface;
   
   class MyController extends AbstractController
   {
       public function __construct(private MemcachedClientInterface $memcached)
       {
       }
   
       public function cacheExample()
       {
           $this->memcached->set('key', 'value', 3600); // Cache for 1 hour
           $value = $this->memcached->get('key');
           return new Response($value ?? 'Not found');
       }
   }
   

Implementation Patterns

Core Workflows

1. Caching Data Use set()/get() for simple key-value caching:

   $this->memcached->set('user_123_data', $userData, 300); // 5-minute TTL
   $cachedData = $this->memcached->get('user_123_data');
   

2. Cache Invalidation Delete keys explicitly:

   $this->memcached->delete('user_123_data');
   

   Or use wildcards (if supported by Memcached server):

   $this->memcached->deleteMulti(['user_*']);
   

3. Tag-Based Invalidation Leverage tags for grouped invalidation (if configured):

   besimple_memcached:
       options:
           tags: true
   

   $this->memcached->add('user_123_data', $data, 300, ['user', 'profile']);
   $this->memcached->deleteByTags(['user']);
   

4. Integration with Symfony Cache Use the bundle’s CacheAdapter for PSR-6 compliance:

   use BeSimple\MemcachedBundle\Cache\MemcachedAdapter;
   
   $cache = $this->container->get('besimple_memcached.cache.adapter');
   $item = $cache->getItem('key');
   

Advanced Patterns

1. Fallback Logic Combine with Symfony’s CacheItemPoolInterface for fallback:

   $cache = $this->container->get('besimple_memcached.cache.adapter');
   $item = $cache->getItem('expensive_data', function (CacheItemInterface $item) {
       $item->expiresAfter(3600);
       return $this->fetchExpensiveData();
   });
   

2. Distributed Locking Use add() with a short TTL for locks:

   $locked = $this->memcached->add('lock_key', true, 5);
   if ($locked) {
       // Critical section
       $this->memcached->delete('lock_key');
   }
   

3. Batch Operations Fetch multiple keys at once:

   $keys = ['key1', 'key2', 'key3'];
   $values = $this->memcached->getMulti($keys);
   

Gotchas and Tips

Common Pitfalls

1. Connection Issues

   • Symptom: Silent failures or timeouts.
   • Fix: Verify servers config and test connectivity:

     telnet 127.0.0.1 11211
     

   • Ensure the Memcached server is running and accessible.

2. Key Collisions

   • Symptom: Unexpected data overwrites due to missing prefixes.
   • Fix: Always use the prefix in config (e.g., myapp_) to namespace keys.

3. TTL Misconfiguration

   • Symptom: Data expires too soon or persists indefinitely.
   • Fix: Use explicit TTLs (e.g., 3600 for 1 hour) and avoid 0 (unlimited).

4. Serialization Errors

   • Symptom: Complex objects fail to cache.
   • Fix: Implement __serialize()/__unserialize() or use json_encode():

     $this->memcached->set('obj', json_encode($object));
     $data = json_decode($this->memcached->get('obj'), true);
     

Debugging Tips

1. Enable Logging Add to config/packages/monolog.yaml:

   handlers:
       memcached:
           type: fingers_crossed
           action_level: error
           handler: nested
           buffer_size: 100
           channels: ["besimple_memcached"]
   

2. Check Stats Use the stats() method to monitor server health:

   $stats = $this->memcached->getStats();
   

3. Test Locally Run Memcached in Docker for development:

   docker run -p 11211:11211 memcached
   

Extension Points

1. Custom Client Configuration Override the default client in config/packages/besimple_memcached.yaml:

   besimple_memcached:
       client_class: App\Service\CustomMemcachedClient
   

2. Event Listeners Subscribe to MemcachedEvents (if the bundle supports them) for pre/post-cache operations:

   // config/services.yaml
   App\EventListener\MemcachedListener:
       tags:
           - { name: kernel.event_listener, event: besimple_memcached.cache.set, method: onCacheSet }
   

3. Proxy Integration Use with Symfony’s HttpCache or ProxyClient for HTTP caching:

   $client = new ProxyClient(
       new MemcachedAdapter($this->memcached),
       new Client()
   );