Small Demo for Demonstrating Vault Client Count 1.9
If you want to enable Client Count on OSS. Check here: https://learn.hashicorp.com/tutorials/vault/usage-metrics#enable-usage-metrics For Enterprise it is enabled by default unless you want to change the retention period.
If you want to create namespaces - a multi tenancy capability in Vault - or a Vault in Vault you will need a Vault Enterprise license.