PUBLIC MARKS with tags symfony & optimization

Jordi Boggiano gives some hints on how to improve the performances of a Symfony2 powered website

The very point of caching is that it's faster and less resource intensive to deliver cached data than creating it on the fly. With existing cache solutions, when the cached data expires, it has to be refreshed while the user waits. In environments that rely heavily on caching, such behavior has the potential to create thread pileups and other cascading failure scenarios. This plugin introduces a cache manager : when an expired âge is called, then it is directly served from the cache, and then the cache gets asynchronously refreshed.