4ROUTER / Observability
Following a request end to end
Connecting admission, execution and accounting.
Engineering note
Give the request a shared identity
A request crossing gateway, model service and records needs correlation. Request identifiers and trace context serve related but distinct purposes. Keep their propagation clear across service boundaries so timestamps refer to the same work.
Record stages, not unnecessary content
Trace spans describe units of work and their timing relationships. Useful stages include queuing, selection, upstream calls and record writes. Do not copy prompts, responses or credentials into telemetry simply for convenience. Collection should match access and retention policies.
Move from a symptom to its path
For a slow request, locate the delayed stage before interpreting errors and resources. Cost discrepancies require attempts and actual usage, not just the final response. Sampled tracing does not replace business records that require complete retention.
Before implementation
- Correlation propagation
- Sensitive-content boundaries
- Retention and access control
