heartbeat

Cauldron.ktl.procedural.heartbeat(service, *args, **kwargs)

Identify keyword (either a keyword name, or a Keyword instance) as a heartbeat keyword for this Service. A heartbeat keyword should broadcast regularly to indicate that the KTL service is functional. period should be set to the maximum expected interval (in seconds) between heartbeat broadcasts.

All hearbeats are monitored by a background FirstResponder thread that wakes up according to the most imminent expiration of any heartbeat’s set period. If the heartbeat does not update within period seconds, an external check will be made to see whether the service is responding. If it is, and local broadcasts have not resumed, all Service instances corresponding to the affected KTL service will be resuscitated. See the FirstResponder class and Paramedic.resuscitate() for details.

Multiple heartbeats may be specified for a single Service instance. This is desirable if distinct dispatchers provide subsets of the keywords within a single KTL service. The failure of any heartbeat will trigger a full resuscitate operation; no attempt is made to distinguish between Keyword instances serviced by distinct dispatchers.

Warning

heartbeat is not implemented in the Cauldron version of the KTL API.