The memcached service is used to cache common data and objects in RAM to reduce the numbers of times they are read from disk and it is used by various OpenStack services.

On the controller node, install memcached:

    # apt install memcached python-memcache

Edit the /etc/memcached.conf file and replace the default listener address with the IP address of the controller node:

• From: 127.0.0.1
• To: 10.10.0.100

Restart the memcached service:

    # systemctl restart memcached