Memcache 是否会对我的性能产生负面影响？

Question

我正在使用 pressflow 6，NewRelic 似乎表明 memcache 确实损害了性能，如下所示：

我的settings.php 文件：

# Varnish reverse proxy on localhost
$conf['reverse_proxy'] = TRUE;           
$conf['reverse_proxy_addresses'] = array('127.0.0.1'); 

# Memcached configuration
$conf['cache_inc'] = './sites/all/modules/memcache/memcache.inc';
$conf['memcache_servers'] = array(
         '127.0.0.1:11211' => 'default',
         );
### END Mercury settings written on 2011-11-01T07:12:49-04:00