Default heartbeats are created as part of partnership creation. If you use a custom heartbeat, the custom heartbeat should be created before you create a partnership. You can modify the properties of the default and custom heartbeats by using the geohb set-prop command. For more information about this command, refer to the geohb (1M) man page.
If you modify the default value of the Query_interval property, ensure that the interval is sufficiently long. An interval that is too short causes a timeout and heartbeat-loss event before the logical hostname resource is available. This failover should result in no more than two unanswered heartbeat requests. Setting a default Query_interval value of 120 seconds with the default heartbeat.retries parameter of 3 enables the peer cluster to be unresponsive for 6 minutes (120 * 3 ) without having a false failure declared.
The heartbeat.retries parameter is specified in the com.sun.cluster.agent.geocontrol.xml file.
If you adjust the delay setting of the Query_interval property, ensure that the following condition is met:
Query_interval > worst-case-logical-host-failover-time / 2
You must empirically determine the logical-host failover time for the cluster in question.
The following must be true to avoid false failures:
Query_interval > worst-case-logical-host-failover-time / 3
You should not change the heartbeat.retries value. If you want to change the default value of the heartbeat.retries property, contact an Oracle service representative.