500 Internal Server Error vs 502 Bad Gateway
500 originates in application code. 502 is generated by a gateway when upstream response is invalid.
| Aspect | 500 Internal Server Error | 502 Bad Gateway |
|---|---|---|
| When it happens | Emitted when conditions specific to 500 internal server error occur. | Emitted when conditions specific to 502 bad gateway occur. |
| How to tell apart | Identify which layer emitted the code and inspect headers/logs for that layer. | Confirm whether problem is auth/policy, upstream quality, overload, or timeout. |
| Troubleshooting first step | Trace request ID through edge and application logs. | Check deploy/config changes and dependency health in same time window. |
| Practical note | Do not mask this response with generic handlers. | Return explicit headers like Retry-After or auth challenge when relevant. |
When each appears in production
Use CDN/proxy logs to find emission point, then app logs/traces to isolate root cause.
Troubleshooting workflow
Validate routing, policy, and timeout budgets in order. Fix the first failing layer before tuning client retries.
Related guides: 500 Internal Server Error · 502 Bad Gateway