Alarm

The Alarm resource lets you manage AWS CloudWatch Alarms for monitoring your AWS resources and applications. You can set alarms based on specific metrics, and take automated actions when those metrics reach a defined threshold.

Minimal Example

Create a basic CloudWatch Alarm that triggers when the CPU utilization exceeds 80%.

import AWS from "alchemy/aws/control";

const cpuAlarm = await AWS.CloudWatch.Alarm("cpuAlarm", {
  ComparisonOperator: "GreaterThanThreshold",
  EvaluationPeriods: 1,
  MetricName: "CPUUtilization",
  Namespace: "AWS/EC2",
  Period: 300,
  Statistic: "Average",
  Threshold: 80,
  AlarmDescription: "Alarm when CPU exceeds 80%",
  AlarmActions: ["arn:aws:sns:us-east-1:123456789012:NotifyMe"],
  OKActions: ["arn:aws:sns:us-east-1:123456789012:NotifyMe"],
  Dimensions: [
    {
      Name: "InstanceId",
      Value: "i-0abcd1234efgh5678"
    }
  ]
});

Advanced Configuration

Configure a CloudWatch Alarm with additional options, such as treating missing data and using extended statistics.

const advancedCpuAlarm = await AWS.CloudWatch.Alarm("advancedCpuAlarm", {
  ComparisonOperator: "GreaterThanThreshold",
  EvaluationPeriods: 2,
  MetricName: "CPUUtilization",
  Namespace: "AWS/EC2",
  Period: 300,
  Statistic: "Average",
  Threshold: 75,
  AlarmDescription: "Advanced Alarm when CPU exceeds 75% for 2 periods",
  AlarmActions: ["arn:aws:sns:us-east-1:123456789012:NotifyMe"],
  InsufficientDataActions: ["arn:aws:sns:us-east-1:123456789012:NotifyMe"],
  TreatMissingData: "breaching",
  ExtendedStatistic: "p90",
  Dimensions: [
    {
      Name: "InstanceId",
      Value: "i-0abcd1234efgh5678"
    }
  ]
});

Custom Metric Alarm

Set an alarm based on a custom metric that tracks application-specific performance.

const customMetricAlarm = await AWS.CloudWatch.Alarm("customMetricAlarm", {
  ComparisonOperator: "GreaterThanThreshold",
  EvaluationPeriods: 3,
  MetricName: "CustomErrorCount",
  Namespace: "MyApplication",
  Period: 60,
  Statistic: "Sum",
  Threshold: 5,
  AlarmDescription: "Alarm for high error count in application",
  AlarmActions: ["arn:aws:sns:us-east-1:123456789012:NotifyMe"],
  Dimensions: [
    {
      Name: "ServiceName",
      Value: "MyService"
    }
  ]
});

Multi-Metric Alarm

Create an alarm that monitors multiple metrics using metric math.

const multiMetricAlarm = await AWS.CloudWatch.Alarm("multiMetricAlarm", {
  ComparisonOperator: "GreaterThanThreshold",
  EvaluationPeriods: 1,
  Metrics: [
    {
      Id: "m1",
      Expression: "SUM(METRICS())",
      Label: "TotalRequests",
      ReturnData: true
    },
    {
      Id: "m2",
      MetricStat: {
        MetricName: "5XXError",
        Namespace: "AWS/ApiGateway",
        Period: 60,
        Stat: "Sum"
      },
      Label: "5XX Errors",
      ReturnData: true
    }
  ],
  Threshold: 10,
  AlarmDescription: "Alarm when total requests exceed errors threshold",
  AlarmActions: ["arn:aws:sns:us-east-1:123456789012:NotifyMe"]
});