4.5.1 Simple Persistence

In this deployment, both Directory Server load balancers are configured for simple persistence. When the load balancer is configured for simple persistence, all Federation Manager requests sent within a specified interval are sent to the same Directory Server for processing. Simple persistence ensures that within the specified interval, no errors or delays occur due to replication time or redirects when retrieving data.

When a request requires information to be written to Directory Server 3SP, that information is also replicated in Directory Server 4SP. But the replication takes time to complete. During that time, if a related request is directed by the load balancer to Directory Server 4SP, the request may fail.

For example, when simple persistence is not configured properly, creating a realm from the Federation Manager administration console could fail in the following way. A request for the parent entry creation is routed to Directory Server 3SP, and a second request to create the subentry is routed to Directory Server 4SP. But if the parent entry request is not yet fully replicated to Directory Server 4SP, the subentry request fails. The result is a partially created realm which may not contain all its subentries such as realm administration roles. Simple persistence eliminates this type of error. When persistence is properly configured, both the parent entry request and the subentry request are routed to Directory Server 3SP. The requests are processed in consecutive order. The parent entry is fully created before the subentry request begins processing.