AWS CloudWatch Dashboards and Alarms

AWS CloudWatch: Dashboards and Alarms

CloudWatch is AWS's native monitoring service, providing metrics, logs, alarms, and dashboards for all AWS resources. While third-party tools offer more flexibility, CloudWatch's deep AWS integration and zero-setup metrics collection make it an essential part of any AWS monitoring strategy.

Custom Dashboards

Create dashboards that show the health of your entire application at a glance:

aws cloudwatch put-dashboard --dashboard-name ProductionOverview --dashboard-body '{
  "widgets": [
    {
      "type": "metric",
      "properties": {
        "metrics": [
          ["AWS/ApplicationELB", "RequestCount", "LoadBalancer", "app/prod-alb/xxx", {"stat": "Sum", "period": 60}],
          ["AWS/ApplicationELB", "HTTPCode_Target_5XX_Count", "LoadBalancer", "app/prod-alb/xxx", {"stat": "Sum", "period": 60}]
        ],
        "title": "ALB Request Count & 5xx Errors",
        "period": 300,
        "view": "timeSeries"
      }
    },
    {
      "type": "metric",
      "properties": {
        "metrics": [
          ["AWS/RDS", "CPUUtilization", "DBInstanceIdentifier", "prod-db"],
          ["AWS/RDS", "DatabaseConnections", "DBInstanceIdentifier", "prod-db"]
        ],
        "title": "RDS Performance"
      }
    }
  ]
}'

Metric Math

Combine metrics with mathematical expressions:

# Error rate percentage
# m1 = 5xx count, m2 = total requests
METRICS(m1/m2*100) AS "Error Rate %"

# Useful expressions:
# ANOMALY_DETECTION_BAND(m1, 2) - automatic anomaly detection
# FILL(m1, 0) - replace missing data points with 0
# RATE(m1) - per-second rate of change

Composite Alarms

Combine multiple alarms to reduce false positives:

# Individual alarms
aws cloudwatch put-metric-alarm \
  --alarm-name high-cpu \
  --metric-name CPUUtilization \
  --namespace AWS/EC2 \
  --statistic Average \
  --period 300 \
  --evaluation-periods 3 \
  --threshold 80 \
  --comparison-operator GreaterThanThreshold

aws cloudwatch put-metric-alarm \
  --alarm-name high-5xx \
  --metric-name HTTPCode_Target_5XX_Count \
  --namespace AWS/ApplicationELB \
  --statistic Sum \
  --period 60 \
  --evaluation-periods 3 \
  --threshold 10 \
  --comparison-operator GreaterThanThreshold

# Composite alarm - only fires when BOTH conditions are true
aws cloudwatch put-composite-alarm \
  --alarm-name production-degraded \
  --alarm-rule 'ALARM("high-cpu") AND ALARM("high-5xx")' \
  --alarm-actions arn:aws:sns:us-east-1:xxx:pagerduty

Anomaly Detection

CloudWatch can automatically learn normal patterns and alert on deviations:

aws cloudwatch put-anomaly-detector \
  --namespace AWS/ApplicationELB \
  --metric-name RequestCount \
  --stat Sum \
  --dimensions Name=LoadBalancer,Value=app/prod-alb/xxx

aws cloudwatch put-metric-alarm \
  --alarm-name request-anomaly \
  --metrics '[{"Id":"m1","MetricStat":{"Metric":{"Namespace":"AWS/ApplicationELB","MetricName":"RequestCount"},"Period":300,"Stat":"Sum"}},{"Id":"ad1","Expression":"ANOMALY_DETECTION_BAND(m1, 2)"}]' \
  --threshold-metric-id ad1 \
  --comparison-operator LessThanLowerOrGreaterThanUpperThreshold

Essential Alarms to Configure

Eazy SaaS Tip: We set up CloudWatch dashboards with a "traffic light" layout: green for healthy, yellow for warning, red for critical. Combined with composite alarms that reduce noise, our clients get actionable alerts — not alarm fatigue.