CloudWatch: Math expression in alarm doesn't respect period #32221
Description
Describe the bug
I'm defining an alarm as follows:
let latencyImpactAlarm: Alarm = new Alarm(
this,
val + "LatencyImpact",
{
alarmName: val + "-node-high-latency-impact",
actionsEnabled: false,
datapointsToAlarm: 3,
evaluationPeriods: 5,
metric: new MathExpression({
period: Duration.seconds(60),
expression: 'TIME_SERIES(0) + ((INSIGHT_RULE_METRIC("' +
latencyRule.ruleName +
'", "MaxContributorValue") / m1) * 100)',
usingMetrics: {
"m1": new Metric({
namespace: "AWS/ApplicationELB",
metricName: "RequestCount",
dimensionsMap: {
"LoadBalancer": value
},
statistic: "Sum",
period: Duration.seconds(60)
})
}
}),
threshold: .1,
comparisonOperator:
ComparisonOperator.GREATER_THAN_OR_EQUAL_TO_THRESHOLD,
},
);This produces CFN as follows:
"Metrics": [
{
"Expression": "TIME_SERIES(0) + ((INSIGHT_RULE_METRIC(\"HighLatencyRequestsPerNode-app-multi--ALBAE-7sFFT5bABDxM-2fa0f6aeb46f1279\", \"MaxContributorValue\") / m1) * 100)",
"Id": "expr_1"
},
{
"Id": "m1",
"MetricStat": {
"Metric": {
"Dimensions": [
{
"Name": "LoadBalancer",
"Value": "app/multi--ALBAE-7sFFT5bABDxM/2fa0f6aeb46f1279"
}
],
"MetricName": "RequestCount",
"Namespace": "AWS/ApplicationELB"
},
"Period": 60,
"Stat": "Sum"
},
"ReturnData": false
}
],When deployed, this causes an error: Resource handler returned message: "Error in expression 'expr_1': Parameter Query Period is invalid. Please specify a Period.
Even though the period is set, it is not included in the synth'd CFN template. If you add in the period manually, the resource successfully deploys.
{
"Expression": "TIME_SERIES(0) + ((INSIGHT_RULE_METRIC(\"HighLatencyRequestsPerNode-app-multi--ALBAE-7sFFT5bABDxM-2fa0f6aeb46f1279\", \"MaxContributorValue\") / m1) * 100)",
"Id": "expr_1",
"Period": 60
},Regression Issue
- Select this option if this issue appears to be a regression.
Last Known Working CDK Version
No response
Expected Behavior
I expect the period field to be included in the resulting CFN.
Current Behavior
It does not.
Reproduction Steps
Provided above.
Possible Solution
No response
Additional Information/Context
No response
CDK CLI Version
2.138.0
Framework Version
No response
Node.js Version
20
OS
darwin
Language
TypeScript
Language Version
No response
Other information
No response