| name | debugging-network |
| description | Investigate network-related replay failures and divergences. Use when replays fail due to network errors, stubbing issues, or request ordering problems. |
Debugging Network Issues
Use this guide when replays fail or diverge due to network request problems.
Investigation Steps
1. Check Logs for Network Errors
- Search
logs.concise.txt for "network", "fetch", "xhr", "request", "response", "timeout".
- Look for failed requests, unexpected status codes, or missing responses.
- Check for CORS errors or SSL issues.
2. Compare Network Activity in Timeline
- In
timeline.json, look for network-related events.
- Compare the sequence and timing of network requests between head and base.
- Look for requests in one replay that are missing in the other.
3. Examine Session Data
- Read session data in
debug-data/sessions/<id>/data.json.
- Check
recordedRequests for the original HAR entries captured during recording.
- Compare recorded requests with what was replayed.
4. Look for Stubbing Issues
- Network requests are stubbed during replay using recorded data.
- Check if new API endpoints were added that don't have recorded responses.
- Look for requests with dynamic parameters (timestamps, tokens) that may not match stubs.
5. Check for Request Ordering Dependencies
- Some applications depend on requests completing in a specific order.
- Look for race conditions where parallel requests resolve differently.
- Check for waterfall dependencies (request B depends on response from request A).
6. Verify API Compatibility
- If the API was changed, recorded responses may no longer be valid.
- Check for schema changes, new required fields, or renamed endpoints.
