1. Correlation turns scattered logs into an investigation path
Without a request ID, logs from controllers, services, database calls and integrations can look unrelated. A correlation identifier lets the team follow one request across layers and services.
This is especially important when the same API serves web, mobile and background jobs.
- Generate or accept a request ID at the HTTP boundary.
- Propagate the ID through logs and downstream calls.
- Return the ID in error responses when useful.
- Train support to capture the ID from user-facing messages.
- Keep the identifier safe and non-sensitive.
2. Structured context beats long unsearchable messages
A log line should be searchable by route, status, duration, user context when safe, request ID and integration name. Long free-text logs make filtering harder during incidents.
The best context is enough to investigate without exposing secrets or personal data unnecessarily.
- Log route, method, status and duration for important requests.
- Separate validation failures from unexpected exceptions.
- Do not log passwords, tokens, secrets or full sensitive payloads.
- Use consistent names for fields across services.
- Record external-call duration separately from total request time.
3. Logs should lead to action
Logs are not useful because they exist. They are useful when they help the team decide what to do next: retry, fix data, change code, improve timeout, adjust validation or document a support procedure.
A lightweight incident note can turn repeated log patterns into future prevention.
- Link repeated failures to root-cause notes.
- Promote useful log patterns into alerts or dashboards.
- Use request IDs in post-incident review.
- Update API documentation when an error is expected behavior.
- Review noisy logs during maintenance routines.
How to use this article
Treat this page as a decision aid. Use it with the related hub, checklist or service route when the topic affects production, customer experience, deployment, security or business continuity.