Alibaba Cloud Prometheus allows you to specify a condition in an alert rule to monitor a metric. If the condition is met, alert events are generated. You can configure a notification policy to send alert notifications by text message, email, phone call, DingTalk chatbot, WeCom chatbot, or webhook.
Prerequisites
A Prometheus instance is created in Managed Service for Prometheus. For more information, see the following topics:
Go to the Create Prometheus Alert Rule page
Log on to the ARMS console.
In the left-side navigation pane, choose .
On the Prometheus Alert Rules page, click Create Prometheus Alert Rule.
Use a preset metric to create an alert rule
ARMS provides various preset metrics. You can select a preset metric and configure an alert rule for the metric.
On the Create Prometheus Alert Rule page, configure the parameters. The following table describes the parameters.
Parameter
Description
Example
Alert Rule 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.
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.
Kubernetes load
Alert Metric
Select a metric. 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
greaterthan 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.
NoteAfter you set the filter conditions, the Data Preview section appears.
Traverse
Data Preview
The Data Preview 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.
NoteThe 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 }}%
Alert Notification
Simple Mode: You need to set the Notification Objects, Notification Period, and Whether to Resend Notifications.
Standard Mode:
Do Not Specify Notification Policy: 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.
ImportantAfter 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 Policy
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
Check after the data is complete
Yes
No
Yes
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
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 a metric other than the preset metrics, you can use a custom PromQL statement to create an alert rule.
On the Create Prometheus Alert Rule page, configure the parameters. The following table describes the parameters.
Parameter
Description
Example
Alert Rule 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.
None
Reference 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.
Kubernetes load
Reference Metrics
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
Enter a PromQL statement.
Namespace: {{$labels.namespace}}/Pod: {{$labels.pod_name}} / The utilization of the {{$labels.device}} disk exceeds 90%. Current value: {{ printf "%.2f" $value }}%max(container_fs_usage_bytes{pod!="", namespace!="arms-prom",namespace!="monitoring"}) by (pod_name, namespace, device)/max(container_fs_limit_bytes{pod!=""}) by (pod_name,namespace, device) * 100 > 90
Data Preview
The Data Preview displays the PromQL statement that corresponds to the alert condition. The section also displays the values of the specified metric in a time series graph.
By default, only the real-time values of one resource are displayed. You can specify filter conditions to view the metric values of different resources in different time ranges.
NoteYou can move the pointer over the curve to view resource details at a specific point in time.
You can also select a time period on the time series curve to view the time series curve of the selected time period.
None
Duration
If the alert condition is met, an alert event is generated: If a data point reaches the threshold, an alert event is generated.
If the alert condition is continuously met for N minutes, an alert event is generated: An alert event is generated only if the duration for which the threshold is reached is greater than or equal to N minutes.
1
Alert Level
Specify the alert level. Default value: Default. Valid values: Default, P4, P3, P2, and P1. Default indicates the lowest severity level, while P1 indicates the highest severity level.
Default
Alert Message
Specify the alert message that you want to send to the end users. You can specify custom variables in the alert message based on the Go template syntax.
Namespace: {{$labels.namespace}} / Pod: {{$labels.pod_name}} / The utilization of the {{$labels.device}} disk exceeds 90%. Current value: {{ printf "%.2f" $value }}%
Alert Notification
Simple Mode: You need to set the Notification Objects, Notification Period, and Whether to Resend Notifications.
Standard Mode:
Do Not Specify Notification Policy: 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.
ImportantAfter 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 Policy
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
Check after the data is complete
Yes
No
Yes
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
Click Save. On the Prometheus 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.
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.
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.