Alarm (List)#
Path: /alarms/alarm-list/alarm
The list of alarms. Each entry in the list holds one alarm for a given alarm type and resource. An alarm can be updated from the underlying resource or by the user. The following leafs are maintained by the resource: ‘is-cleared’, ‘last-change’, ‘perceived-severity’, and ‘alarm-text’. An operator can change ‘operator-state’ and ‘operator-text’. Entries appear in the alarm list the first time an alarm becomes active for a given alarm type and resource. Entries do not get deleted when the alarm is cleared. Clear status is represented as a boolean flag. Alarm entries are removed, i.e., purged, from the list by an explicit purge action. For example, purge all alarms that are cleared and in closed operator state that are older than 24 hours. Purged alarms are removed from the alarm list. If the alarm resource state changes after a purge, the alarm will reappear in the alarm list. Systems may also remove alarms based on locally configured policies; this is out of scope for this module.
Parameters#
| Name | Type | Required | Default | Description |
|---|---|---|---|---|
| time-created | date-and-time | required | The timestamp when this alarm entry was created. This represents the first time the alarm appeared; it can also represent that the alarm reappeared after a purge. Further state changes of the same alarm do not change this leaf; these changes will update the ‘last-changed’ leaf. | |
| self-test | boolean | optional | false | True if this alarm was triggered by a self test operation. Self test alarms do not indicate any issues in the system. |
| impact-tree | string | optional | ||
| description | string | optional | ||
| resource-type | string | optional | ||
| resource | resource | required | The alarming resource. See also ‘alt-resource’. This could be, for example, a reference to the alarming interface | |
| alarm-type-id | alarm-type-id | required | This leaf and the leaf ‘alarm-type-qualifier’ together provide a unique identification of the alarm type. | |
| alarm-type-qualifier | alarm-type-qualifier | required | This leaf is used when the ‘alarm-type-id’ leaf cannot uniquely identify the alarm type. Normally, this is not the case, and this leaf is the empty string. | |
| alt-resource | multi-value, resource | optional | Used if the alarming resource is available over other interfaces. This field can contain SNMP OIDs, CIM paths, or 3GPP distinguished names, for example. | |
| impacted-resource | multi-value, resource | optional | Resources that might be affected by this alarm. If the system creates an alarm on a resource and also has a mapping to other resources that might be impacted, these resources can be listed in this leaf-list. In this way, the system can create one alarm instead of several. For example, if an interface has an alarm, the ‘impacted-resource’ can reference the aggregated port channels. | |
| root-cause-resource | multi-value, resource | optional | Resources that are candidates for causing the alarm. If the system has a mechanism to understand the candidate root causes of an alarm, this leaf-list can be used to list the root-cause candidate resources. In this way, the system can create one alarm instead of several. An example might be a logging system (alarm resource) that fails; the alarm can reference the file system in the ‘root-cause-resource’ leaf-list. Note that the intended use is not to also send an alarm with the ‘root-cause-resource’ as an alarming resource. The ‘root-cause-resource’ leaf-list is a hint and should not also generate an alarm for the same problem. | |
| is-cleared | boolean | required | Indicates the current clearance state of the alarm. An alarm might toggle from active alarm to cleared alarm and back to active again. | |
| last-raised | date-and-time | required | An alarm may change severity level and toggle between active and cleared during its lifetime. This leaf indicates the last time it was raised (‘is-cleared’ = ‘false’). | |
| last-changed | date-and-time | required | A timestamp when the ‘status-change’ or ‘operator-state-change’ list was last changed. | |
| perceived-severity | severity | required | The last severity of the alarm. If an alarm was raised with severity ‘warning’ but later changed to ‘major’, this leaf will show ‘major’. | |
| alarm-text | alarm-text | required | The last reported alarm text. This text should contain information for an operator to be able to understand the problem and how to resolve it. |
Subsections#
| Name | Type | Description |
|---|---|---|
| operator-state-change | List | This list is used by operators to indicate the state of human intervention on an alarm. For example, if an operator has seen an alarm, the operator can add a new item to this list indicating that the alarm is acknowledged. |
| related-alarm | List | References to related alarms. Note that the related alarm might have been purged from the alarm list. |
| status-change | List | A list of status-change events for this alarm. The entry with latest timestamp in this list MUST correspond to the leafs ‘is-cleared’, ‘perceived-severity’, and ‘alarm-text’ for the alarm. This list is ordered according to the timestamps of alarm state changes. The first item corresponds to the latest state change. The following state changes create an entry in this list: - changed severity (warning, minor, major, critical) - clearance status; this also updates the ‘is-cleared’ leaf - alarm-text update |