To monitor Classic Load Balancer (CLB) instances and get notified when performance metrics cross a threshold, configure alert rules in CloudMonitor. You can set up alert rules through the CloudMonitor console or by calling CloudMonitor API operations.
If you delete a CLB instance or a listener, CloudMonitor also deletes all alert rules configured for that instance or listener. You can also use the Alert Rules link in the CLB instance monitoring panel to check whether monitoring alert rules have already been configured for a specific instance.
The health check feature of CLB only monitors the availability of backend servers. Health check exceptions do not automatically trigger alert notifications. To receive alerts when health checks detect failures, you must manually configure alert rules in the CloudMonitor console and select health check–related metrics.
Note the difference between alert types:
Health check alerts — Must be manually created. Relevant metrics are located under the
acs_slb_dashboardnamespace and includeUnhealthyServerCount(number of unhealthy backend ECS instances) andHeathyServerCount(number of healthy backend ECS instances).Quota alerts — Automatically created by the system (for example, SLB quota usage alerts under the
acs_quotas_commonquotanamespace). Quota alerts cannot replace health check alerts.
Prerequisites
Before you begin, ensure that you have:
Activated CloudMonitor
Created at least one alert contact and one alert contact group in CloudMonitor.
A CLB instance with at least one listener added and health checks enabled:
The CloudMonitor service label for CLB:
SLBThe CloudMonitor namespace for CLB:
acs_slb_dashboard. To get the namespace, call DescribeProjectMeta
Configure alert rules in the CloudMonitor console
Before creating a new alert rule, you can check whether alert rules are already configured for a CLB instance: navigate to the CloudMonitor console > Alert Center > Alert Rules.
This path starts from the CLB console and automatically scopes the alert rule to the selected instance.
Log on to the CLB console.
Log on to the CLB console.
In the top navigation bar, select the region where the CLB instance resides.
On the Instances page, find the instance and click the
icon in the Monitoring column.In the Monitoring Information panel, click Alert Rules. This link opens the Alert Rules page in CloudMonitor and automatically filters the view to the current CLB instance.
On the Alert Rules page of the CloudMonitor console, click Create Alert Rule.
On the Alert Rules page, you can check whether alert rules have been configured for the current instance:
If the list contains rule entries, alert rules have been configured.
If the list is empty or displays No Data, no alert rules have been configured for this instance. To create an alert rule, click Create Alert Rule.
In the Create Alert Rule panel, configure the alert rule parameters. For details, see Create an alert rule.
Configure alert rules by calling API operations
The following figure shows the API workflow for configuring alert rules.
(Optional) Call
DescribeMetricMetaListto query the descriptions of time series metrics available in CloudMonitor. Alternatively, see Monitoring and alerting metrics.Call
PutContactto create or modify an alert contact.Call
PutContactGroupto create or modify an alert contact group.Call
PutResourceMetricRuleto configure a threshold-triggered alert rule for a CLB performance metric.Call
DescribeMetricRuleListto query alert rules.