Comment 5 for bug 1332058

Currently, keystone is not ready for High availability and doesn't give any control on HA options for memcached.
I think there should be some specific values in keystone.conf where operators can tune libmemcached or pylibmc better than default settings.

[cache]
backend_behaviors=

This option should specify the behavior for backend (http://sendapatch.se/projects/pylibmc/behaviors.html#failover)

    regions.behaviors = {
        "tcp_nodelay": False,
        "ketama": True,
        "failure_limit": 2,
        "_retry_timeout": 30,
        "_auto_eject_hosts": True
    }

and toss all these settings during dogpile backend registration as specified at https://pypi.python.org/pypi/dogpile.cache