This symfony bundle <a href="https:&#x2F;&#x2F;github.com&#x2F;LeaseWeb&#x2F;LswMemcacheBundle" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;LeaseWeb&#x2F;LswMemcacheBundle</a> uses specifically the php-memcache extension. Thats why we need it