The following figure illustrates the most basic deployment architecture for OpenSSO Enterprise in single sign-on environment. A list of the components that comprise the architecture follows.
Two instances of OpenSSO Enterprise provide the core functionality. Each instance is configured with its own embedded configuration data store. Configuration data includes information about services, administrative users, realms, policies, and more. User data is accessed through a single load balancer deployed in front of two instances of Sun Java System Directory Server.
The Distributed Authentication User Interface is a component of OpenSSO Enterprise that provides a thin presentation layer for user authentication. During user authentication, the Distributed Authentication User Interface interacts with OpenSSO Enterprise to retrieve credentials from the user data store, thus protecting the OpenSSO Enterprise servers from direct user access. The Distributed Authentication User Interface does not directly interact with the user data store.
Two instances of Directory Server provide storage for the OpenSSO Enterprise user data. Both instances of Directory Server are masters that engage in multi-master replication. Multi-master replication allows data to be synchronized in real time between two directories, providing high availability to the OpenSSO Enterprise layer.
Policy agents are used to restrict access to hosted content or applications. The policy agents intercept HTTP requests from external users and redirect the request to OpenSSO Enterprise for authentication. Web policy agents protect any resources under the doc root of the web container. J2EE policy agents protect a variety of hosted J2EE applications; in this deployment, agentsample is used. The agents communicate with the OpenSSO Enterprise instances through one of two configured load balancers.
The protected resources host machines contain the content for which access is restricted. Towards this end, web servers, application servers and policy agents will be installed. Two load balancers are configured in front of the host machines to balance traffic passing through the policy agents.
OpenSSO Enterprise uses two instances of Message Queue to form a cluster for distributing client connections and delivering messages. The Berkeley Database by Sleepycat Software, Inc. is the session store database. When an instance of OpenSSO Enterprise goes down and session failover is enabled, the user's session token can be retrieved from one of the Message Queues by the available instance of OpenSSO Enterprise. This ensures that the user remains continuously authenticated, allowing access to the protected resources without having to reauthenticate.
The load balancer hardware and software used for this deployment is BIG-IP® manufactured by F5 Networks. They are configured for simple persistence and deployed as follows:
Distributed Authentication User Interface Load Balancer. This external-facing load balancer exposes the remote, web-based Distributed Authentication User Interface for user authentication and self-registration.
OpenSSO Enterprise Load Balancer. This internal-facing load balancer exposes the web-based OpenSSO Enterprise console to internal administrators. Alternatively, internal administrators can bypass this load balancer and log in directly.
J2EE Policy Agents Load Balancer. The load balancer in front of the J2EE policy agents installed on the Protected Resource machines provides round-robin load balancing and a single virtual server by balancing traffic passing through the agents.
Web Policy Agents Load Balancer. The load balancer in front of the web policy agents installed on the Protected Resource machines provides round-robin load balancing and a single virtual server by balancing traffic passing through the agents.
Directory Server Load Balancer. The load balancer in front of the Directory Server instances provide round-robin load balancing and a single virtual Directory Server host name for the instances of OpenSSO Enterprise. It detects individual Directory Server failures and recoveries, taking failed servers off the load balancer list.
For detailed instructions on how to deploy these components, see Deployment Example: Single Sign-On, Load Balancing and Failover Using Sun OpenSSO Enterprise 8.0.