Distributed Data Synchronization (DSync)

Clusters

NAS Clusters

Set of NAS that share a single source for session and state data

Session

A continuous series of interactions between a user and a Netscape Application Server application. The term session is widely used to refer to a Web browser session, but with NAS, session refers more specifically to a series of user interactions that are tracked by a Netscape Application Server application. The user's session with a Web browser or other client software might start before the NAS application begins tracking the user, and could continue after the application stops tracking the user.

State

A distributed data storage mechanism for storing the state of a collection of application variables whose scope is global within the application. Information in the state layer can be organized in a hierarchical structure, or tree.

High Availability

Because state and session information is stored and retrieved from from a single server in a cluster, new requests can execute on any server in the cluster.

Failover

By eliminating single points of failure, Netscape Application Server offers maximum application availability. Distributed state and session management prevent loss of user or application data if a failure occurs. (Instances of requests may be lost at the time of failure, but the session and application will persist).

High Scalability

Application scaling can be performed either by adding more servers to a cluster of servers or by adding more CPUs to a multi-CPU system.

Application components can then be deployed to the new servers. Developers do not need to change any application logic as the deployment base grows.