Find the useful clues in application logs — CloudWatch Logs

Your goal

Plan logs that help explain an application failure without exposing secrets.

Why this matters

A customer reports a failed request. You will collect useful event details, narrow the search, and set rules for access and retention so logs stay helpful and controlled.

Words you will use

A log event records something that happened. A log group organizes related logs. A request ID connects events from one request. Retention controls how long logs are kept.

How to proceed

Read each situation and choose an answer. The lesson explains the result. Try again if needed, then continue through all three decisions and finish the tour.

1. Record useful details

Your app currently writes only “error,” making every failure look the same. The team needs context without copying passwords or private payloads.

What should the app record?

Useful structured fields such as time, request ID, and safe error details.

Structured fields make events easier to search and compare. Include identifiers and safe context that help explain the failure, while excluding credentials and unnecessary personal data. More logging is not automatically better logging.

Events have useful, safe investigation clues.

Timestamp + request ID + safe event fields → log event

2. Narrow the investigation

The customer provides a request ID and approximate time. Searching all logs forever would be slow and noisy. Choose a focused query.

Where should you start?

Relevant log groups, a narrow time range, and the request ID.

Use the known time and identifier to find related events, then widen the search if needed. A focused query reduces noise and unnecessary work. Compare the sequence instead of drawing a conclusion from one line alone.

The investigation follows the reported request.

Relevant group + time range + request ID → related events

3. Set a retention and access plan

The logs help support staff but contain operational details and continue growing. The team needs an intentional storage policy.

What should be configured?

Appropriate retention, access permissions, and monitoring of log volume.

Choose retention based on investigation and organizational needs. Restrict who can read or change logs and monitor volume. Useful evidence should remain available for the needed period without becoming an uncontrolled data store.

Logs have a clear lifetime and access boundary.

Defined retention + limited access + volume review

Practice, then check your understanding

In the interactive tour, make each decision before seeing the outcome. Wrong answers receive coaching, and replay gives you a fresh attempt without duplicating earned XP.

Read the official AWS documentation for service behavior and production details.