Hi,

That's exactly what we're doing as well. Works fine in terms of availability, although it feels we're missing out with regard to cache, and there's performance that could gain.

On our backlog there's a ticket about a HA (preferably distributed) memcache-replacement (or extension).

Anyone who did this already?

Cheers,
Kees

On 13-05-2025 08:22, Eugen Block wrote:

we were facing the same thing when we reinstalled our cloud to be highly available. We had a list of memcached servers for all the required services, and then noticed that a failed control node would disrupt our services. We could pinpoint it to memcached not being highly-available despite having a list of servers. So we decided to point all services to localhost only:

# nova
root@controller02:~# grep memcached /etc/nova/nova.conf
memcached_servers = localhost:11211

# Dashboard
CACHES = {
    'default': {
        'BACKEND': 'django.core.cache.backends.memcached.PyMemcacheCache',
        'LOCATION': '127.0.0.1:11211',
    },
}

This has been working great for years now.