High performance setup is just as high availability setup, difference is that high performance setup uses Redis to store data that is in the default setup stored in LDAP. This reduces the IO and makes possible the vertical scaling of SSO installations. For instruction on how to install and configure Redis cluster, please read Redis documentation.
This instruction covers two SSO nodes cluster setup. When installing more SSO nodes the process in still the same → install LDAP, install SSO and copy configuration, as in high availability cluster installation.