| No Data | No Data | The default option for **No Data** events.<br/>Sets alert instance state to `No Data`. <br/> The alert rule also creates a new alert instance `DatasourceNoData` with the name and UID of the alert rule, and UID of the datasource that returned no data as labels. |
| Error | Error | The default option for **Error** events.<br/>Sets alert instance state to `Error`. <br/> The alert rule also creates a new alert instance `DatasourceError` with the name and UID of the alert rule, and UID of the datasource that returned no data as labels. |
| No Data or Error | Alerting | Sets the alert instance state to `Pending` and then transitions to `Alerting` once the pending period ends. If you sent the pending period to 0, the alert instance state is immediately set to `Alerting`. |
| No Data or Error | Normal | Sets alert instance state to `Normal`. |
| No Data or Error | Keep Last State | Maintains the alert instance in its last state. Useful for mitigating temporary issues. |
