Failover and Scalability in Sun Cluster

Sun Cluster enables you to implement applications on either a failover or scalable basis. Failover and scalable applications can also run on the same cluster concurrently. In general, a failover application provides high availability (redundancy), whereas a scalable application provides high availability along with increased performance. A single cluster can support both failover and scalable applications.

Failover

Failover is the process by which the cluster automatically relocates an application from a failed primary node to a designated secondary node. With failover, Sun Cluster provides high availability.

When a failover occurs, clients might see a brief interruption in service and might need to reconnect after the failover has finished. However, clients are not aware of the physical server from which they are provided the application and data.

Scalability

While failover is concerned with redundancy, scalability provides constant response time or throughput without regard to load. A scalable application leverages the multiple nodes in a cluster to concurrently run an application, thus providing increased performance. In a scalable configuration, each node in the cluster can provide data and process client requests.

Refer to "Data Services" for more specific information on failover and scalable services.