Failure Detection and Takeover Properties for HA Clusters

The following configuration properties (listed in Table 14–10) specify the parameters for the exchange of heartbeat and status information within an HA cluster:

• imq.cluster.heartbeat.hostname gives the host name (or IP address) for the heartbeat connection service.

• imq.cluster.heartbeat.port gives the port number for the heartbeat connection service.

• imq.cluster.heartbeat.interval defines the interval, in seconds, at which heartbeat packets are transmitted.

• imq.cluster.heartbeat.threshold specifies the number of missed heartbeat intervals after which a broker is considered suspect of failure.

• imq.cluster.monitor.interval defines the interval, in seconds, at which to monitor a suspect broker’s state information to determine whether it has failed.

• imq.cluster.monitor.threshold specifies the number of elapsed monitor intervals after which a suspect broker is considered to have failed.

Smaller values for these heartbeat and monitoring intervals will result in quicker reaction to broker failure, but at the cost of reduced performance and increased likelihood of false suspicions and erroneous failure detection.