The Timing tab of each Threshold Condition properties dialog offers the option to set 'Acknowledgement required by operator'. When selected this option requires the operator to acknowledge each time that the Threshold condition is activated.
To understand how this works, it helps to understand the different state transitions of the PROBSTATE field of the PROBLEM record. Available states will depend whether the 'Acknowledgement required by operator' option has been selected in the Threshold Timing page and whether an off-event was configured for the Problem Log destination. The following scenarios will demonstrate the various options.
In the first scenario, an 'Acknowledgement required by operator' option has been selected together with an Off Event. In this case when the Threshold condition is activated it will go into the OPENACK state. If the Off Event occurs first then the problem will automatically go into a CLOSEACK state, meaning that the problem is now resolved but it still needs to be acknowledged by the operator. Once acknowledged by the operator it will go into the CLOSED state. Alternatively, if the operator acknowledges the OPENACK status first, the problem will go into the OPEN state, meaning that the problem has been acknowledged but it still exists. When the Off Event occurs, the problem will automatically go into the CLOSED state.
In this scenario, another problem instance will not be re-opened while one is still in the CLOSEACK state, i.e. the same problem will not be detected again until the current instance is closed. See Scenario 2 for the option to avoid this situation.
This scenario has the same conditions as Scenario 1, except that the following statement has been added to the ALERTS Configuration file:
For further details see the ALERTS Configuration Syntax.
After this statement has been added to the configuration, should a further identical ON event occur, the problem state will revert back from CLOSEACK to OPENACK.
In the second scenario only the 'Acknowledgement required by operator' option has been set, there is no Off Event. In this case when a Threshold condition is activated the problem will go into the OPENACK state. Once the operator has acknowledged this it will go straight to a CLOSED state. As no Off Event has been set there is no check that the problem has actually been resolved.
In the next scenario, an Off Event has been set without any 'Acknowledgement required by operator'. In this case when the Threshold condition is activated it will go into the OPEN state and when the Off Event is detected it will go automatically to the CLOSED state.
The last scenario shows when no 'Acknowledgement required by operator' or OFF Event is set. In this case the problem will go straight to the CLOSED state.
See also the How to Acknowledge Alerts.