Application Real-Time Monitoring Service:Create an alert rule for a Prometheus instance

Procedure

1. Log on to the ARMS console.
2. In the left-side navigation pane, choose Prometheus Service > Prometheus Alert Rules.
3. In the upper-right corner of the Prometheus Alert Rules page, click Create Prometheus Alert Rule.

Use a preset metric to create an alert rule

If you set the Check Type parameter to Static Threshold, you can select a preset metric and create an alert rule template by using the metric.

1. On the Create Prometheus Alert Rule page, configure the parameters. The following table describes the parameters.

   Parameter	Description	Example
   Alert Name	Enter the name of the alert rule.	Production cluster - container CPU utilization alert
   Check Type	Select Static Threshold.	Static Threshold
   Prometheus Instance	Select the Prometheus instance for which you want to create the alert rule.	Production cluster
   Alert Contact Group	Select an alert contact group. The alert contact groups that are supported by a Prometheus instance vary based on the type of the Prometheus instance. The options in the drop-down list vary based on the type of the Prometheus instance that you specify.	Kubernetes load
   Alert Metric	Select the metric that you want to monitor by using the alert rule. Different alert contact groups provide different metrics.	Container CPU utilization
   Alert Condition	Specify the condition based on which alert events are generated.	If the CPU utilization of the container is greater than 80%, an alert event is generated.
   Filter Conditions	Specify the applicable scope of the alert rule. If a resource meets both the filter condition and the alert condition, an alert event is generated. The following types of filter conditions are supported: Traverse: The alert rule applies to all resources in the current Prometheus instance. By default, Traverse is selected. Equal: If you select this filter condition, you must enter a resource name. The alert rule applies only to the specified resource. You cannot specify multiple resources at the same time. Not equal: If you select this filter condition, you must enter a resource name. The alert rule applies to resources other than the specified resource. You cannot specify multiple resources at the same time. Regex match: If you select this filter condition, you must enter a regular expression to match resource names. The alert rule that you create by using the template applies to all resources that match the regular expression. Regex not match: If you select this filter condition, you must enter a regular expression to match resource names. The alert rule applies to resources that do not match the regular expression. Note After you set the filter conditions, the Data Preview section appears.	Traverse
   Data Preview	The Data Preview section displays the PromQL statement that corresponds to the alert condition. The section also displays the values of the specified metric in a time series graph. By default, only the real-time values of one resource are displayed. You can specify filter conditions to view the metric values of different resources in different time ranges. Note The threshold in the time series graph is represented by a red line. The part of the curve that meets the alert condition is displayed in dark red, and the part of the curve that does not meet the alert condition is displayed in blue. You can move the pointer over the curve to view resource details at a specific point in time. You can also select a time period on the time series curve to view the time series curve of the selected time period.	None
   Duration	If the alert condition is met, an alert event is generated: If a data point reaches the threshold, an alert event is generated. If the alert condition is continuously met for N minutes, an alert event is generated: An alert event is generated only if the duration for which the threshold is reached is greater than or equal to N minutes.	1
   Alert Level	Specify the alert level. Default value: Default. Valid values: Default, P4, P3, P2, and P1. Default indicates the lowest severity level, while P1 indicates the highest severity level.	Default
   Alert Message	Specify the alert message that you want to send to the end users. You can specify custom variables in the alert message based on the Go template syntax.	Namespace: {{$labels.namespace}} / Pod: {{$labels.pod_name}} / Container: {{$labels.container}} CPU utilization: {{$labels.metrics_params_opt_label_value}} {{$labels.metrics_params_value}}%. Current value: {{ printf "%.2f" $value }}%
   Advanced Settings
   Alert Check Cycle	An alert rule is triggered every N minutes to check whether the alert conditions are met. Default value: 1. Minimum value: 1.	1
   Specify Notification Policies	Do Not Specify Notification Policies: If you select this option, you can create a notification policy on the Notification Policy page after you create the alert rule. On the Notification Policy page, you can specify match rules and match conditions. For example, you can specify an alert rule name as the match condition. When the alert rule is triggered, an alert event is generated and an alert notification is sent to the contacts or contact groups that are specified in the notification policy. For more information, see Create and manage a notification policy. You can also select a notification policy from the drop-down list. ARMS automatically adds a match rule to the selected notification policy and specifies the ID of the alert rule as the match condition. The name of the alert rule is displayed on the Notification Policy page. This way, the alert events that are generated based on the alert rule can be matched by the selected notification policy. Important After you select a notification policy, the alert events that are generated based on the alert rule can be matched by the notification policy and alerts can be generated. The alert events may also be matched by other notification policies that use fuzzy match, and alerts may be generated. One or more alert events can be matched by one or more notification policies.	Do Not Specify Notification Policies
   Tags	Specify tags for the alert rule. The specified tags can be used to match notification policies.	None
   Annotations	Specify annotations for the alert rule.	None

2. Click Save. On the Prometheus Alert Rules page, check the status of the alert rule.
   If Automatic Interruption appears in the Status column, modify the alert rule as prompted and click Start in the Actions column. In the message that appears, click OK. If the issue persists after you apply the preceding solution, contact technical support (DingTalk ID: d9j_rg9e4062f).

   An alert rule may be automatically interrupted due to the following reasons:

   • The number of results queried by the alert rule exceeds 1,500.
   • No notification object is configured.
   • The Prometheus instance is uninstalled or unavailable.

Use a custom PromQL statement to create an alert rule

To monitor metrics other than the preset metrics, you can use a custom PromQL statement to create an alert rule.

1. On the Create Prometheus Alert Rule page, configure the parameters. The following table describes the parameters.

   Parameter	Description	Example
   Alert Name	Enter the name of the alert rule.	Pod CPU utilization exceeds 8%
   Check Type	Select Custom PromQL.	Custom PromQL
   Prometheus Instance	Select the Prometheus instance for which you want to create the alert rule.	None
   Reference alarm indicator	Optional. The reference metrics drop-down list displays common metrics. After you select a metric, the PromQL statement of the metric is displayed in the Custom PromQL Statements field. You can modify the statement based on your business requirements. The values in the reference metrics drop-down list vary based on the type of the Prometheus instance.	Pod disk usage alert
   Custom PromQL Statements	Specify the PromQL statement based on which alert events are generated.	max(container_fs_usage_bytes{pod!="", namespace!="arms-prom",namespace!="monitoring"}) by (pod_name, namespace, device)/max(container_fs_limit_bytes{pod!=""}) by (pod_name,namespace, device) * 100 > 90
   Data Preview	The Data Preview section displays the time series graph of resources that meet the specified conditions in the PromQL statement. By default, the alert data of all resources that meet the specified conditions in the PromQL statement is displayed. You can configure filter conditions to display the data of a specific resource in a specific time range. Note You can move the pointer over the curve to view resource details at a specific point in time. You can also select a time period on the time series curve to view the time series curve of the selected time period.	None
   Duration	If the alert condition is met, an alert event is generated: If a data point reaches the threshold, an alert event is generated. If the alert condition is continuously met for N minutes, an alert event is generated: An alert event is generated only if the duration for which the threshold is reached is greater than or equal to N minutes.	1
   Alert Level	Specify the alert level. Default value: Default. Valid values: Default, P4, P3, P2, and P1. Default indicates the lowest severity level, while P1 indicates the highest severity level.	Default
   Alert Message	Specify the alert message that you want to send to the end users. You can specify custom variables in the alert message based on the Go template syntax.	Namespace: {{$labels.namespace}} / Pod: {{$labels.pod_name}} / The utilization of the {{$labels.device}} disk exceeds 90%. Current value: {{ printf "%.2f" $value }}%
   Advanced Settings
   Alert Check Cycle	An alert rule is triggered every N minutes to check whether the alert conditions are met. Default value: 1. Minimum value: 1.	1
   Specify Notification Policies	Do Not Specify Notification Policies: If you select this option, you can create a notification policy on the Notification Policy page after you create the alert rule. On the Notification Policy page, you can specify match rules and match conditions. For example, you can specify an alert rule name as the match condition. When the alert rule is triggered, an alert event is generated and an alert notification is sent to the contacts or contact groups that are specified in the notification policy. For more information, see Create and manage a notification policy. You can also select a notification policy from the drop-down list. ARMS automatically adds a match rule to the selected notification policy and specifies the ID of the alert rule as the match condition. The name of the alert rule is displayed on the Notification Policy page. This way, the alert events that are generated based on the alert rule can be matched by the selected notification policy. Important After you select a notification policy, the alert events that are generated based on the alert rule can be matched by the notification policy and alerts can be generated. The alert events may also be matched by other notification policies that use fuzzy match, and alerts may be generated. One or more alert events can be matched by one or more notification policies.	Do Not Specify Notification Policies
   Tags	Specify tags for the alert rule. The specified tags can be used to match notification policies.	None
   Annotations	Specify annotations for the alert rule.	None

2. Click Save. On the Prometheus Alert Rules page, check the status of the alert rule.
   If Automatic Interruption appears in the Status column, modify the alert rule as prompted and click Start in the Actions column. In the message that appears, click OK. If the issue persists after you apply the preceding solution, contact technical support (DingTalk ID: d9j_rg9e4062f).

   An alert rule may be automatically interrupted due to the following reasons:

   • The number of results queried by the alert rule exceeds 1,500.
   • No notification object is configured.
   • The Prometheus instance is uninstalled or unavailable.

Manage an alert rule

On the Prometheus Alert Rules page, you can view, enable, disable, modify, or delete an alert rule.

1. Optional: On the Prometheus Alert Rules page, configure filter conditions or enter an alert name in the search box, and then click the Search icon.
2. Perform the following operations on an alert rule by using the options in the Actions column based on your business requirements:
   • To modify an alert rule, click Edit. On the Edit Prometheus Alert Rules page, modify the alert rule and click Save.
   • To delete an alert rule, click Delete. In the Confirm message, click OK.
   • To enable an alert rule, click Start. In the Confirm message, click OK.
   • To disable an alert rule, click Stop. In the Confirm message, click OK.
   • To view historical alert events, click Alert Event History. On the Events page, you can view historical alert events.