Package software.amazon.awscdk.services.cloudwatch

Interface MathExpressionProps

All Superinterfaces:

software.amazon.jsii.JsiiSerializable, MathExpressionOptions

All Known Implementing Classes:

MathExpressionProps.Jsii$Proxy

@Generated(value="jsii-pacmak/1.119.0 (build 1634eac)",
           date="2025-11-17T14:40:47.352Z")
@Stability(Stable)
public interface MathExpressionProps
extends software.amazon.jsii.JsiiSerializable, MathExpressionOptions

Properties for a MathExpression.

Example:

 MatchmakingRuleSet matchmakingRuleSet;
 // Alarm that triggers when the per-second average of not placed matches exceed 10%
 MathExpression ruleEvaluationRatio = MathExpression.Builder.create()
         .expression("1 - (ruleEvaluationsPassed / ruleEvaluationsFailed)")
         .usingMetrics(Map.of(
                 "ruleEvaluationsPassed", matchmakingRuleSet.metricRuleEvaluationsPassed(MetricOptions.builder().statistic(Statistic.SUM).build()),
                 "ruleEvaluationsFailed", matchmakingRuleSet.metric("ruleEvaluationsFailed")))
         .build();
 Alarm.Builder.create(this, "Alarm")
         .metric(ruleEvaluationRatio)
         .threshold(0.1)
         .evaluationPeriods(3)
         .build();
 

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static final class	MathExpressionProps.Builder	A builder for MathExpressionProps
static final class	MathExpressionProps.Jsii$Proxy	An implementation for MathExpressionProps

Method Summary

Modifier and Type	Method	Description
static MathExpressionProps.Builder	builder()
String	getExpression()	The expression defining the metric.
default Map<String,IMetric>	getUsingMetrics()	The metrics used in the expression, in a map.

Methods inherited from interface software.amazon.jsii.JsiiSerializable

$jsii$toJson

Methods inherited from interface software.amazon.awscdk.services.cloudwatch.MathExpressionOptions

getColor, getLabel, getPeriod, getSearchAccount, getSearchRegion

Method Details

getExpression

@Stability(Stable)
@NotNull
String getExpression()

The expression defining the metric.

When an expression contains a SEARCH function, it cannot be used within an Alarm.

getUsingMetrics

@Stability(Stable)
@Nullable
default Map<String,IMetric> getUsingMetrics()

The metrics used in the expression, in a map.

The key is the identifier that represents the given metric in the expression, and the value is the actual Metric object.

The period of each metric in usingMetrics is ignored and instead overridden by the period specified for the MathExpression construct. Even if no period is specified for the MathExpression, it will be overridden by the default value (Duration.minutes(5)).

Example:

 IApplicationLoadBalancerMetrics metrics;
 MathExpression.Builder.create()
         .expression("m1+m2")
         .label("AlbErrors")
         .usingMetrics(Map.of(
                 "m1", metrics.custom("HTTPCode_ELB_500_Count", MetricOptions.builder()
                         .period(Duration.minutes(1)) // <- This period will be ignored
                         .statistic("Sum")
                         .label("HTTPCode_ELB_500_Count")
                         .build()),
                 "m2", metrics.custom("HTTPCode_ELB_502_Count", MetricOptions.builder()
                         .period(Duration.minutes(1)) // <- This period will be ignored
                         .statistic("Sum")
                         .label("HTTPCode_ELB_502_Count")
                         .build())))
         .period(Duration.minutes(3))
         .build();
 

Default: - Empty map.

builder

@Stability(Stable)
static MathExpressionProps.Builder builder()

Returns:

a MathExpressionProps.Builder of MathExpressionProps