CloudWatch helps observe AWS systems. Billing tools help control cost. The shared responsibility model defines what AWS secures and what you must secure.
CloudWatch
CloudWatch collects operational data.
Common CloudWatch features:
- Logs.
- Metrics.
- Alarms.
- Dashboards.
- Events.
Backend systems use CloudWatch to understand health, errors, latency, and resource usage.
Logs
CloudWatch Logs stores application and service logs.
Examples:
- Lambda logs.
- ECS logs.
- EC2 application logs.
- API Gateway logs.
Logs are useful only if they are structured and searchable.
Metrics and alarms
Metrics are numeric measurements over time.
Examples:
- CPU usage.
- Memory usage.
- Error count.
- Request latency.
- Database connections.
Alarms notify you when a metric crosses a threshold.
Billing and cost controls
AWS cost can grow quickly without monitoring.
Use:
- Budgets.
- Cost Explorer.
- Billing alerts.
- Tags for cost allocation.
- Reserved or savings plans when usage is predictable.
For learning accounts, billing alerts are mandatory.
Shared responsibility
AWS is responsible for security of the cloud. You are responsible for security in the cloud.
| AWS handles | You handle |
|---|---|
| Physical data centers | IAM permissions |
| Hardware | Network rules |
| Managed service infrastructure | Data classification |
| Global infrastructure | Application security |
Quick revision
- CloudWatch provides logs, metrics, alarms, and dashboards.
- Billing tools protect against surprise cost.
- Tags help understand where cost comes from.
- AWS secures the cloud infrastructure.
- You secure your usage, data, identities, and applications.