If you would like the platform to notify you when an alarm activates, create an Alert for it in Control view. Alerts are a group of one or more alarms. They are like a worker monitoring a group of alarms; when all the lights for the group are lit up, the alert is activated. Alerts can also trigger action plans to perform automated actions when their alarms activate. After you create an alert, create an action plan in Control view with the alert as a trigger.
You can create alarms for built-in VM metrics or scaling group metrics, as well as custom metrics created using the API for VMs, scaling groups, virtual appliances, and virtual datacenters.
Virtual datacenters → Alarms
Before you begin:
To create an alarm:
|Entity type||Select an entity with metrics from the list on the left.|
|Entity name||The name of the entity|
|Entity label||The label of the entity, which for VMs is shown in the list on the left|
|Entity icon||The icon that the platform displays in the UI for VMs and virtual appliances|
Name of the alarm with up to 128 characters. Alarm names must be unique for each metric
|Description||Description of the alarm. Used together with the alarm name and VM name to identify the alarm, for example, when creating an alert|
|Metric||Select one of the metrics available for the VM|
|Metric unit||The unit of the metric. Read only|
|Metric description||The description of the metric. Read only|
|Dimension||When the metric has multiple dimensions, optionally select one or more dimensions. For example, if a VM has multiple hard disks, then the disk read bytes metric may have a dimension for each disk|
Last datapoints in period
The number of datapoints that the platform will evaluate the metric during the elapsed time. The default value is All data points and the minimum value of the time period is 1 minute.
If you request the evaluation of an alarm more frequently than metric data is collected by the platform or sent by the provider, then the alarm will not activate.
The platform collects metrics data every 2 minutes by default, but this can be changed using a property for each plugin. For the default configuration, to ensure that an alarm will activate, it should be evaluated at intervals of greater than 2 minutes.
Moreover, each provider transmits metrics at different intervals, for example, with Amazon Basic monitoring, data is sent every 5 minutes, and with Advanced monitoring, every minute. For vCloud, data is available on consultation.
Note that for alarms with longer evaluation periods, for example, an average of 10 points over the last hour, the transmission and collection intervals will not affect the activation of the alarm.
Statistic that the platform will use for evaluating the alarm, which can be: average, maximum, minimum, sum, count, dev
Operator that the platform will use for evaluation of the alarm, for example, greater than. Values can be: notequal, greaterthan, greaterthanorequalto, lessthan, lessthanorequalto, trendup, trenddown
Value that the platform will evaluate the alarm against, if appropriate
The platform will create the alarm for the metric. If you would like the platform to notify you when an alarm is triggered, create an Alert.
For a scaling group, an alarm on a metric of the VM in the base workload will receive input from the metrics of all VMs in the scaling group. This means the base workload and/or the clone VMs. So an alarm for a scaling group can activate, even if the base workload is not deployed.
For API documentation about alarms on an entity, see the API documentation for the entity's resource. For example, for VMs, see VirtualMachinesResource.
When you edit an alarm, there is an extra field, "Active", that shows if the alarm is activated or not.
After you save the alarm, the platform will start to evaluate it again with new data when it receives the next set of metrics datapoints.
You can also remove an alarm from an alert.
To delete an alarm:
To remove an alarm from an alert:
Go to Control → Alerts → edit alert
Select the alarm, click the delete button, and confirm
The platform will remove it from this alert, but it will remain in all other alerts that it is associated with
If you delete a VM, the platform will delete any alarms associated with its metrics.