Application users must be authenticated. The Application Server provides three different choices for user authentication: file-based, LDAP, and Solaris.
The default file based security realm is suitable for developer environments, where new applications are developed and tested. At deployment time, the server administrator can choose between the Lighweight Directory Access Protocol (LDAP) or Solaris security realms. Many large enterprises use LDAP-based directory servers to maintain employee and customer profiles. Small to medium enterprises that do not already use a directory server may find it advantageous to leverage investment in Solaris security infrastructure.
For more information on security realms, see Chapter 9, Configuring Security, in Sun Java System Application Server Enterprise Edition 8.1 2005Q2 Administration Guide.
The type of authentication mechanism chosen may require additional hardware for the deployment. Typically a directory server executes on a separate server, and may also require a backup for replication and high availability. Refer to Sun Java System Directory Server documentation for more information on deployment, sizing, and availability guidelines.
An authenticated user’s access to application functions may also need authorization checks. If the application uses the role-based J2EE authorization checks, the application server performs some additional checking, which incurs additional overheads. When you perform capacity planning, you must take this additional overhead into account.