Multi-instance WordPress usingn Memcached to handle sessions requests login every time a requests is handled by a different server
I have WordPress running in Kubernetes with horizontal autoscaling, my site uses BuddyPress to provide social-networking functionality. I also have a memcached server accessed by all the deployments of the website, and PHP session handler set as memcached with the appropriate path.
Despite this setup, which I believe should allow logged-in users to talk to any deployment without being asked to log in again, whenever the server changes the user is redirected to the login page.
Sticky sessions are not an option as I want to have autoscalability as well as the option to roll-out new deployments, which would be compromised by sticky session.