Opcache Profiler Bundle Laravel Package

Getting Started

Minimal Setup

1. Install via Composer:

   composer require codepoet/opcache-profiler-bundle:^1.0
   

   (Note: For Symfony 2.0.x, use the gist workaround.)

2. Enable the Bundle: Add to config/bundles.php (Symfony 4+) or AppKernel.php (Symfony 2/3):

   new Codepoet\OpcacheProfilerBundle\CodepoetOpcacheProfilerBundle(),
   

3. First Use Case: Access any Symfony profiler page (e.g., /_profiler/). The Opcache tab will appear in the toolbar, showing:

   • Cache status (enabled/disabled)
   • Memory usage
   • Hit/miss ratios
   • Cached script count

Implementation Patterns

Core Workflows

1. Debugging Performance Bottlenecks:

   • Use the hit/miss ratio to identify uncached scripts (high misses = Opcache inefficiency).
   • Correlate with Symfony profiler timings to spot slow scripts that should be cached.

2. Monitoring During Deployment:

   • After deploying, check the filelist (if enabled) to verify critical classes are cached.
   • Watch for memory spikes post-deploy (may indicate cache invalidation issues).

3. Environment-Specific Config:

   # config/packages/dev/codepoet_opcache_profiler.yaml
   codepoet_opcache_profiler:
       data_collector:
           show_filelist: true  # Only enable in dev/staging
           cache_stats: true    # Show detailed cache stats
   

4. Integration with CI/CD:

   • Add a pre-deploy check (e.g., via PHPUnit) to fail if Opcache hit ratio < 90% in staging.

Advanced Patterns

• Custom Metrics: Extend the OpcacheDataCollector to log cache events to a monitoring system (e.g., Datadog):

  // src/EventListener/OpcacheListener.php
  use Codepoet\OpcacheProfilerBundle\DataCollector\OpcacheDataCollector;
  
  public function onKernelRequest(GetResponseEvent $event) {
      $opcache = $event->getKernel()->getContainer()
          ->get('codepoet_opcache_profiler.data_collector');
      if ($opcache->getMissCount() > 10) {
          // Trigger alert
      }
  }
  

• Dynamic Filelist Filtering: Override the getFileList() method to exclude vendor/ or cache/ directories:

  // config/services.yaml
  Codepoet\OpcacheProfilerBundle\DataCollector\OpcacheDataCollector:
      arguments:
          $showFilelist: true
          $filelistFilter: '~^(?!.*(vendor|cache))~'
  

Gotchas and Tips

Pitfalls

1. Memory Overhead:

   • show_filelist: true can consume hundreds of MB for large apps. Enable only in dev/staging.
   • Fix: Use opcache.get_status() directly in CLI scripts for lightweight checks.

2. Symfony 4+ Compatibility:

   • The bundle targets Symfony 2/3. For Symfony 4+, ensure config/bundles.php is used instead of AppKernel.
   • Fix: Check the Symfony 4 migration guide for bundle loading.

3. Opcache Disabled:

   • The toolbar may show no data if Opcache is off. Verify with:

     php -i | grep opcache.enable
     

   • Fix: Enable Opcache in php.ini (opcache.enable=1) and restart PHP-FPM.

4. Filelist Inconsistencies:

   • The filelist may lag behind real-time changes (e.g., after opcache_reset()).
   • Tip: Refresh the profiler tab or run opcache_reset() in CLI to sync.

Debugging Tips

• CLI Debugging: Use opcache_get_status() in a script to bypass the toolbar:

  $status = opcache_get_status();
  var_dump($status['opcache_statistics']);
  

• Log Cache Events: Add this to config/packages/monolog.yaml to log Opcache misses:

  handlers:
      opcache:
          type: stream
          path: "%kernel.logs_dir%/opcache.log"
          level: debug
          channels: ["opcache"]
  

  Then log misses in a subscriber:

  public function onKernelRequest(RequestEvent $event) {
      $misses = opcache_get_status()['opcache']['miss_count'];
      if ($misses > 0) {
          $this->logger->debug('Opcache misses', ['misses' => $misses]);
      }
  }
  

Extension Points

1. Custom Data Collection: Extend OpcacheDataCollector to add metrics like:

   • Script execution time (from Symfony profiler).
   • File modification timestamps (to detect stale cache).

2. Toolbar Integration: Override the Twig template (templates/CodepoetOpcacheProfilerBundle:Toolbar:opcache.html.twig) to:

   • Add visual warnings for high miss rates.
   • Include a "Clear Opcache" button (calls opcache_reset()).

3. Asynchronous Monitoring: Use a cron job to log Opcache stats to a database:

   */5 * * * * php /path/to/script.php opcache:stats >> /var/log/opcache.log
   

   Script example:

   // script/opcache:stats.php
   $stats = opcache_get_status();
   file_put_contents(
       '/var/log/opcache.json',
       json_encode($stats['opcache_statistics'])
   );