AWS — CloudWatch

What is CloudWatch?

Monitoring and observability service for AWS resources.

Metrics

# Get metrics
aws cloudwatch get-metric-statistics \
  --namespace AWS/EC2 \
  --metric-name CPUUtilization \
  --start-time 2024-01-01T00:00:00Z \
  --end-time 2024-01-01T23:59:59Z \
  --period 3600 \
  --statistics Average \
  --dimensions Name=InstanceId,Value=i-1234567890abcdef0

Alarms

aws cloudwatch put-metric-alarm \
  --alarm-name high-cpu \
  --metric-name CPUUtilization \
  --namespace AWS/EC2 \
  --statistic Average \
  --period 300 \
  --threshold 80 \
  --comparison-operator GreaterThanThreshold \
  --evaluation-periods 2 \
  --alarm-actions arn:aws:sns:us-east-1:123456789:my-topic

Logs

# Create log group
aws logs create-log-group --log-group-name /my/app

# Create log stream
aws logs create-log-stream \
  --log-group-name /my/app \
  --log-stream-name my-stream

# Put log events
aws logs put-log-events \
  --log-group-name /my/app \
  --log-stream-name my-stream \
  --log-events timestamp=1234567890,message="Hello"

Dashboards

aws cloudwatch put-dashboard \
  --dashboard-name MyDashboard \
  --dashboard-body '{"widgets":[{"type":"metric","x":0,"y":0,"width":12,"height":6,"properties":{"metrics":[["AWS/EC2","CPUUtilization","InstanceId","i-1234567890abcdef0"]]}}]}'

Custom metrics

import boto3

cloudwatch = boto3.client('cloudwatch')
cloudwatch.put_metric_data(
    Namespace='MyApp',
    MetricData=[{
        'MetricName': 'Requests',
        'Value': 100,
        'Unit': 'Count'
    }]
)

Best practices

1. Set up alarms
2. Use dashboards
3. Enable detailed monitoring
4. Set log retention

Mini Practice

1. Create an alarm
2. View metrics
3. Set up logging
4. Create a dashboard

Up Next

Continue with CloudFormation - Infrastructure as Code.