If no alert is triggered when the corresponding metric value reaches the specified threshold, perform the operations described in this topic to troubleshoot the issue.
Background information
Each alert condition is an expression that contains a metric, an alert level, a period, and a threshold. The period of a metric indicates the interval between two consecutive data points and the aggregation period of metric values. For example, if the period of a metric is 60 seconds, a data point is generated every 60 seconds. A metric value is the aggregate value that is calculated based on the monitoring data of the previous 60 seconds. The detection period of an alert rule is determined by the period. If a multi-metric expression contains multiple periods, the shortest period prevails.
The aggregation method varies based on the metric. For more information, see Appendix 1: Metrics. You can view the Statistics column of a specific cloud service on the TimeSeries Metrics page. If the value of the Statistics parameter that is configured for an alert rule is not the value of the Statistics parameter of the corresponding metric, the status of the alert rule is normal and no alert is generated.
The period of each metric varies. For more information, see Appendix 1: Metrics. You can view the Min Periods column of a specific cloud service on the TimeSeries Metrics page.
Procedure
In this example, the maximum value of the CPU Utilization metric of an Elastic Compute Service (ECS) instance is greater than or equal to 90% in three consecutive periods.
View the monitoring data of the CPU Utilization metric, especially the maximum value and period.
For more information about how to view the monitoring data of other cloud services, see View the monitoring data.
Log on to the Cloud Monitor console.
In the left-side navigation pane, click .
On the Host Monitoring page, find the host that you want to manage, and click the host name or Monitoring Charts in the Actions column.
On the Basic Monitoring tab, view the monitoring chart of the CPU Utilization metric and check the maximum value and period.
View the latest threshold-triggered alert rule of the CPU Utilization metric, and then check whether the alert condition is met.
In the left-side navigation pane, choose .
On the Alert Rules page, find the alert rule that you want to view and click More in the Actions column.
On the More tab, view the alert condition that contains the threshold and period, effective time, alert status, and associated resources. If the maximum value of the CPU Utilization metric of the ECS instance is greater than or equal to 90% in three consecutive periods, the alert condition is met. Make sure that the alert status is normal and the alert rule is effective.
Check whether the ECS instance is added to a blacklist.
In the left-side navigation pane, choose .
On the Alert Blacklists page, check whether the ECS instance is added to a blacklist.
The specified mute period of an alert rule for Container Service for Kubernetes (ACK) applies to all the associated resources in the alert rule. For example, you set the mute period to 24 hours. In this case, Cloud Monitor sends only one alert notification within 24 hours after a pod triggers an alert, even if another pod meets the specified alert condition. If the level of an alert triggered by a pod changes, Cloud Monitor sends an alert notification.