Network outage reported on Atlas, Luna, and Sol platforms. Investigation with the NOC indicates a null-route was applied upstream to stem a deluge of packets originating from these servers on a memcached 0-day amplification attack. memcached access has been restricted to local-only. Moreover, for any users running memcached on your account, you are encouraged to switch to socket-based.
memcached -s /tmp/memcached.sock
Then to access memcached from a PHP application change relevant code to use the socket rather than 127.0.0.1:
$memcached->addServer($_SERVER['SITE_ROOT'] . '/tmp/memcached.sock');
Ruby, Python, Node, Go, and shell tasks do not require usage of the environment variable, "SITE_ROOT".