Use evaluate expressions to define trigger conditions for alert monitoring rules. For example, set Trigger Condition to Data matches the expression and enter an evaluate expression. An alert triggers when query and analysis results match the expression.
Overview
In an alert rule, you can specify the results of query statements as the input and the fields in the results of set operations as variables. If the evaluate expression returns true, an alert is triggered.
Configure a trigger condition
In a trigger condition, the evaluate expression is used to evaluate the results of set operations. If the evaluate expression returns true, an alert is triggered. The trigger conditions support the following options:
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Data is returned: Checks the number of data entries in the set operation result. Triggers if at least one data entry exists.
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The query result contains: Checks if the number of data entries in the set operation result meets a specified threshold. Supported operators include greater than, less than, and equal to. For example, if the result has 4 entries and the trigger condition is The query result contains > 10 entries, the condition is not met, and no alert is generated.
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Data matches the expression: Checks the content of the data entries in the set operation result. Triggers if the content of at least one data entry matches the evaluate expression. For example, if the result is one entry (
pv=900) and the trigger condition is Data matches the expression, pv > 1000, the condition is not met, and no alert is generated.
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The query result contains and matches: Checks both the number of data entries and their content. Triggers only when a specified number of data entries match the evaluate expression. For example, if the result has four entries (
pv=900,pv=1100,pv=1200,pv=1001) and the trigger condition is The query result contains and matches > 3, pv > 1000, the condition is met, and an alert is generated.