Using Sub-Realms in OpenSSO Again & Again
By docteger on Jul 16, 2008
In general, you should use the default root realm (
opensso) to configure identity data stores, and manage policies and authentication chains. After deployment, OpenSSO creates a Realm Administrator who can perform all operations in the configured root realm, and a Policy Administrator who can only create and manage policies. The use of sub-realms in OpenSSO should be restricted to the following two scenarios.
- Application Policy Delegation The use case for this is when you need to have different Policy Administrators to create policies for a sub-set of resources. For example, let's assume a sub-realm is created and named Paycheck. This sub-realm is configured with a policy referral from the root realm for configuring protection of resources starting with
https://paycheck.sun.com/paycheck. Within the Paycheck sub-realm, a Paycheck Administrator role or group is created and assigned Policy Administration privileges. These administrators are now able to login to the sub-realm and create policies for their applications. By default, the sub-realm inherits the same configuration data store and authentication chains configured for its parent; if these configurations change in the parent, a corresponding change would be needed in the sub-realm. Additionally, all users will still log in to the root realm for access to all the applications. The sub-realm is primarily for the Policy Administrator to manage policies for the application. An educated guess on the number of sub-realms that can be supported would be about 100.
- ISP/ASP/Silo The use case for this scenario is when each sub-realm is to have its own set of identity data stores, authentication chains, and policies. Ideally the only common thread between the root and the sub-realm would be the referral policy created in the root realm to delegate a set of resources to the sub-realm. Users would not be able to log in to the root realm (unless they are a member) but would have to authenticate to their sub-realm. Also, agents would have to be configured to redirect user authentication to the particular sub-realm. With regards to performance, the most resource consuming component would be when persistent searches created by the data stores connect to the same directory. An educated guess on the number of sub-realms that can be supported would be about 50.