I have servers and 1 memcached server linked by the network. When I add 2 memcached on the 2 servers, locally, it's drastically faste !
So I've configured Drupal to use memcached on 127.0.0.1, except for sessions. The sessions are the only data hosted on the network server (MC 3).
DRUPAL 1 DRUPAL 2 MC 1 MC 2 \ / \ / \ / MC 3 Sessions
It's fine, except for the cache flush because when I do a
drush cc all, Drupal 1 will only flush MC1, and Drupal2 only MC2, but not both.
The idea is to force Drupal to clear all the memcached, but to use only the localhost + MC3.
What is your advice, add a hook to clear both servers?