Most of OpenStack services use an application to offer persistence and store ephemeral data (like tokens). Memcached is one of them and can scale-out easily without any specific tricks required. To install and configure it, read the official documentation. Memory caching is managed by oslo-incubator so the way to use multiple memcached servers is the same for all projects. Example with two hosts: memcached_servers = controller1:11211,controller2:11211 By default, controller1 handles the caching service but if the host goes down, controller2 does the job. For more information about memcached installation, see the OpenStack Cloud Administrator Guide.