The following recommendations are based on the test results:
If your environment demands a large number of users active throughout the day, scaling the memory to hold these user sessions is recommended. For example, all users keep their portal or mailbox open throughout the day. However, if the environment demands more users activities such as logins per second / requests per second, scaling the CPU is recommended for faster processing. For example, trading systems where a large number of users log in at the same time and leave the session quickly.
A total number of users in the LDAP user store is not significant for determining hardware for Access Manager components.
When usage is high on accessing web servers and applications, more Access Gateways are required.
When usage is high on users and authentication, more Identity Servers are required.
Two nodes in a cluster are given as the minimum recommended configuration to have fault tolerance.
The setup needs to be evaluated in a real-world usage of the use case.