Package software.amazon.awscdk.services.cloudwatch

Class Alarm

java.lang.Object
software.amazon.jsii.JsiiObject
software.constructs.Construct
software.amazon.awscdk.Resource
software.amazon.awscdk.services.cloudwatch.AlarmBase
software.amazon.awscdk.services.cloudwatch.Alarm
All Implemented Interfaces:
IEnvironmentAware, IResource, IAlarm, IAlarmRule, software.amazon.jsii.JsiiSerializable, software.constructs.IConstruct, software.constructs.IDependable
Direct Known Subclasses:
AnomalyDetectionAlarm
@Generated(value="jsii-pacmak/1.119.0 (build 1634eac)", date="2025-11-17T14:40:47.271Z") @Stability(Stable) public class Alarm extends AlarmBase
An alarm on a CloudWatch metric.

Example: 

 LogGroup logGroup;
 MetricFilter mf = MetricFilter.Builder.create(this, "MetricFilter")
         .logGroup(logGroup)
         .metricNamespace("MyApp")
         .metricName("Latency")
         .filterPattern(FilterPattern.exists("$.latency"))
         .metricValue("$.latency")
         .dimensions(Map.of(
                 "ErrorCode", "$.errorCode"))
         .unit(Unit.MILLISECONDS)
         .build();
 //expose a metric from the metric filter
 Metric metric = mf.metric();
 //you can use the metric to create a new alarm
 //you can use the metric to create a new alarm
 Alarm.Builder.create(this, "alarm from metric filter")
         .metric(metric)
         .threshold(100)
         .evaluationPeriods(2)
         .build();

  • Field Details

    • ANOMALY_DETECTION_NO_THRESHOLD

      @Stability(Stable) public static final Number ANOMALY_DETECTION_NO_THRESHOLD
      Conventional value for the threshold property when creating anomaly detection alarms.

      Anomaly detection alarms don't have numbered threshold. Instead, they have a dynamically calculated threshold based on the metric math expression that contains a metric expression.

      The threshold property is required, but the value is ignored. This constant has the value 0, and has a symbolic name to indicate why the threshold is 0. You can use new AnomalyDetectionAlarm() to avoid having to pass the threshold property at all.

    • PROPERTY_INJECTION_ID

      @Stability(Stable) public static final String PROPERTY_INJECTION_ID
      Uniquely identifies this class.

  • Constructor Details

    • Alarm

      protected Alarm(software.amazon.jsii.JsiiObjectRef objRef)

    • Alarm

      protected Alarm(software.amazon.jsii.JsiiObject.InitializationMode initializationMode)

    • Alarm

      @Stability(Stable) public Alarm(@NotNull software.constructs.Construct scope, @NotNull String id, @NotNull AlarmProps props)
      Parameters:
      scope - This parameter is required.
      id - This parameter is required.
      props - This parameter is required.

  • Method Details

    • fromAlarmArn

      @Stability(Stable) @NotNull public static IAlarm fromAlarmArn(@NotNull software.constructs.Construct scope, @NotNull String id, @NotNull String alarmArn)
      Import an existing CloudWatch alarm provided an ARN.

      Parameters:
      scope - The parent creating construct (usually this). This parameter is required.
      id - The construct's name. This parameter is required.
      alarmArn - Alarm ARN (i.e. arn:aws:cloudwatch::invalid input: '<'account-id>:alarm:Foo). This parameter is required.

    • fromAlarmName

      @Stability(Stable) @NotNull public static IAlarm fromAlarmName(@NotNull software.constructs.Construct scope, @NotNull String id, @NotNull String alarmName)
      Import an existing CloudWatch alarm provided an Name.

      Parameters:
      scope - The parent creating construct (usually this). This parameter is required.
      id - The construct's name. This parameter is required.
      alarmName - Alarm Name. This parameter is required.

    • addAlarmAction

      @Stability(Stable) public void addAlarmAction(@NotNull IAlarmAction... actions)
      Trigger this action if the alarm fires.

      Typically SnsAction or AutoScalingAction.

      Overrides:
      addAlarmAction in class AlarmBase
      Parameters:
      actions - This parameter is required.

    • toAnnotation

      @Stability(Stable) @NotNull public HorizontalAnnotation toAnnotation()
      Turn this alarm into a horizontal annotation.

      This is useful if you want to represent an Alarm in a non-AlarmWidget. An AlarmWidget can directly show an alarm, but it can only show a single alarm and no other metrics. Instead, you can convert the alarm to a HorizontalAnnotation and add it as an annotation to another graph.

      This might be useful if:

      • You want to show multiple alarms inside a single graph, for example if you have both a "small margin/long period" alarm as well as a "large margin/short period" alarm.
      • You want to show an Alarm line in a graph with multiple metrics in it.

    • getAlarmArn

      @Stability(Stable) @NotNull public String getAlarmArn()
      ARN of this alarm.
      Specified by:
      getAlarmArn in interface IAlarm
      Specified by:
      getAlarmArn in class AlarmBase

    • getAlarmName

      @Stability(Stable) @NotNull public String getAlarmName()
      Name of this alarm.
      Specified by:
      getAlarmName in interface IAlarm
      Specified by:
      getAlarmName in class AlarmBase

    • getMetric

      @Stability(Stable) @NotNull public IMetric getMetric()
      The metric object this alarm was based on.