title: Use redis to cache duplicate requests in symfony2
body: <p>This is my current setup:</p>
  
  <pre><code>snc_redis:
      clients:
          default:
              type: predis
              alias: cache
              dsn: "redis://127.0.0.1"
      doctrine:
              metadata_cache:
                  client: cache
                  entity_manager: default
                  document_manager: default
              result_cache:
                  client: cache
                  entity_manager: [bo, aff, fs]
              query_cache:
                  client: cache
                  entity_manager: default
  </code></pre>
  
  <p>I have an API which gets multiple duplicate requests (usually in quick succession), can I use this setup to send back a cached response on duplicate request? Also is it possible to set cache expiry?</p>