Conditions

Updated: May 06, 2022

Conditions are associated with entities; a condition represents the entity's state.

Condition Description
CONDDEATH The entity has died.
CONDABNORMALDEATH The entity has died an abnormal death. Whenever an entity dies, this condition is triggered by a mechanism that results in the generation of a core dump file.
CONDDETACH The entity that was being monitored is detaching. This ends the HAM's monitoring of that entity.
CONDATTACH An entity for whom a place holder was previously created (i.e., some process has subscribed to events relating to this entity) has joined the system. This is also the start of the HAM's monitoring of the entity.
CONDHBEATMISSEDHIGH The entity missed sending a “heartbeat” message specified for a condition of “high” severity.
CONDHBEATMISSEDLOW The entity missed sending a “heartbeat” message specified for a condition of “low”
CONDRESTART The entity was restarted. This condition is true after the entity is successfully restarted.
CONDRAISE An externally detected condition is reported to the HAM. Subscribers can associate actions with these externally detected conditions.
CONDSTATE An entity reports a state transition to the HAM. Subscribers can associate actions with specific state transitions.
CONDANY This condition type matches any condition type. It can be used to associate the same actions with one of many conditions.

For the conditions listed above (except CONDSTATE, CONDRAISE, and CONDANY), the HAM is the publisher—it automatically detects and/or triggers the conditions. For the CONDSTATE and CONDRAISE conditions, external detectors publish the conditions to the HAM.

For all conditions, subscribers can associate with lists of actions that will be performed in sequence when the condition is triggered. Both the CONDSTATE and CONDRAISE conditions provide filtering capabilities, so subscribers can selectively associate actions with individual conditions based on the information published.

Any condition can be associated as a wild card with any entity, so a process can associate actions with any condition in a specific entity, or even in any entity. Note that conditions are also associated with symbolic names, which also need to be unique within an entity.