Sun Cluster 3.1 Data Services Developer's Guide


The probe command periodically checks the health of the given application. It must be a UNIX command complete with its arguments that can be passed directly to a shell to probe the application. The probe command returns with an exit status of 0 if the application is OK.

The exit status of the probe command is used to determine the severity of the failure of the application. This exit status, called probe status, must be an integer between 0 (for success) and 100 (for complete failure). The probe status can also be a special value of 201 which results in immediate failover of the application unless Failover_enabled is set to false. The probe status is used within the GDS probing algorithm (see scds_fm_action(3HA)) to make the decision about restarting the application locally versus failing it over to another node; if the exit status is 201, the application is immediately failed over.

If the probe command is omitted, the GDS provides its own simple probe that connects to the application on the set of IP addresses derived from the Network_resources_used property or the output of scds_get_netaddr_list(3HA). If the connect succeeds, it disconnects immediately. If both connect and disconnect succeed, the application is deemed to be running healthily.

Note –

The probe provided with the GDS is only intended to be a simple substitute for the fully functioning application-specific probe.