159. CloudWatch Metrics & CloudWatch Alarms Overview

Amazon CloudWatch

provides metrics for every services in AWS

Metric

a variable to monitor
Metrics have timestamps
Can create CloudWatch dashboards of metrics

Important Metrics

• EC2 instances: CPU Utilization, Status Checks, Network (not RAM)
• Default metrics every 5 minutes

• Option for Detailed Monitoring ($$$): metrics every 1 minute

• EBS volumes: Disk Read/Writes

• S3 buckets: BucketSizeBytes, NumberOfObjects, AllRequests • Billing: Total Estimated Charge (only in us-east-1)

• Service Limits: how much you’ve been using a service API

• Custom metrics: push your own metrics

Amazon CloudWatch Alarms

used to trigger notifications for any metric

Alarms actions...

• Auto Scaling: increase or decrease EC2 instances “desired” count
• EC2 Actions: stop, terminate, reboot or recover an EC2 instance
• SNS notifications: send a notification into an SNS topic