Sun Cluster system makes all components on the ”path” between users and data highly available by monitoring the applications themselves, the file system, and network interfaces.
The Sun Cluster software detects a node failure quickly and creates an equivalent server for the resources on the failed node. The Sun Cluster software ensures that resources unaffected by the failed node are constantly available during the recovery and that resources of the failed node become available as soon as they are recovered.
Each Sun Cluster data service supplies a fault monitor that periodically probes the data service to determine its health. A fault monitor verifies that the application daemon or daemons are running and that clients are being served. Based on the information returned by probes, predefined actions such as restarting daemons or causing a failover, can be initiated.
Sun Cluster software supports disk-path monitoring (DPM). DPM improves the overall reliability of failover and switchover by reporting the failure of a secondary disk-path. You can use one of two methods for monitoring disk paths. The first method is provided by the scdpm command. This command enables you to monitor, unmonitor, or display the status of disk paths in your cluster. See the scdpm(1M) man page for more information about command-line options.
The second method for monitoring disk paths in your cluster is provided by the SunPlex Manager graphical user interface (GUI). SunPlex Manager provides a topological view of the monitored disk paths. The view is updated every 10 minutes to provide information about the number of failed pings.
Each cluster node has its own IP network multipathing configuration, which can differ from the configuration on other cluster nodes. IP network multipathing monitors the following network communication failures:
The transmit and receive path of the network adapter has stopped transmitting packets.
The attachment of the network adapter to the link is down.
The port on the switch does not transmit-receive packets.
The physical interface in a group is not present at system boot.