If data loss occurs during a collection process, Log Service collect no data. To detect and prevent this issue, you can use the no-data alert feature.
- The CPU utilization of a host exceeds 95%.
- No data exists in query results.
- Query Statistics: Enter
* | select promql_query_range('cpu_util') from metrics limit 1000.
This query statement is used to calculate the CPU utilization of each host.
- Trigger Condition: Select data matches the expression and enter value > 95.
If the value of a value field in the query result is greater than 95, an alert is triggered.
- Threshold of Continuous Triggers: If the number of continuous triggers reaches the specified threshold, an alert is triggered.
- No Data Alert: Turn on the No Data Alert switch, and set the Severity and Add Annotation parameters.
If no data is returned for a query, an alert is triggered. If you enable the no-data alert feature, an alert is triggered only when the number of continuous triggers exceeds the specified threshold of continuous triggers.
You can specify the severity and annotations for a no-data alert.