Error message

Notice: MemcachePool::set(): Server ec2-54-235-122-115.compute-1.amazonaws.com (tcp 11211, udp 0) failed with: Connection refused (111) in dmemcache_set() (line 44 of /var/www/vibe.com/Vibe/htdocs/sites/all/modules/memcache/dmemcache.inc).