Memcache in conjunction with Varnish and APC, any configuration tweks needed?

I'm optimizing the performance of a Drupal 7 website and I have varnish, memcache and APC all installed and working with their individual Drupal 7 modules. I'm using a single memcache instance and my server is in the cloud so I can just massively scale up the machine if needed.

In my settings php I have the $config options below. My question is to get better performance and have all these caches work together well, do I need to add more configuration options? It appears like the module readme assumes a single cache system. Are there any tweaks needed to get better performance out of running 3 separate caching backends?

// Add Varnish as the page cache handler.
$conf['cache_backends'][] = 'sites/all/modules/varnish/varnish.cache.inc'; $conf['cache_class_cache_page'] = 'VarnishCache'; // Drupal 7 does not cache pages when we invoke hooks during bootstrap. // This needs to be disabled. $conf['page_cache_invoke_hooks'] = FALSE;

$conf['cache_backends'][] = 'sites/all/modules/apc/drupal_apc_cache.inc'; $conf['cache_class_cache'] = 'DrupalAPCCache'; $conf['cache_class_cache_bootstrap'] = 'DrupalAPCCache'; //$conf['apc_show_debug'] = TRUE; // Remove the slashes to use debug mode.

$conf['cache_backends'][] = 'sites/all/modules/memcache/memcache.inc'; $conf['cache_default_class'] = 'MemCacheDrupal'; $conf['cache_class_cache_form'] = 'DrupalDatabaseCache';