Intermittent DNS_PROBE_FINISHED_NXDOMAIN on Railway-generated domain (.up.railway.app)
pedroandriani
PROOP

3 months ago

Hi Railway team,

I'm experiencing intermittent DNS resolution issues with my Railway-generated domain (not a custom domain).

Issue:

- Domain: be-your-future-copywriting.up.railway.app

- Error: DNS_PROBE_FINISHED_NXDOMAIN

- The service shows "Online" in the dashboard, logs show normal execution

- Deployments complete successfully

- Redeploy temporarily fixes the issue, but it comes back after some time

Environment:

- Region: us-west2

- Service: n8n (Node.js application)

- Architecture: Primary + Worker + Redis + Postgres

What I've tried:

- Flushing local DNS cache (ipconfig /flushdns)

- Accessing via incognito/private window

- Accessing from mobile on 4G

- Redeploy (works temporarily)

Observations:

- The issue happens multiple times per day

- When it fails, all tests (incognito, mobile, different networks) fail

- Redeploy fixes it temporarily but it returns

- No errors in deploy logs when this happens

This is affecting production workflows. Is there any known issue with DNS for .up.railway.app domains in us-west2, or something I should check on my end?

$10 Bounty

1 Replies

pedroandriani
PROOP

3 months ago

Update - RESOLVED:

Found and fixed two separate issues:

Issue 1: X-Forwarded-For / Rate Limiter Error

  • Cause: n8n wasn't configured to trust the Railway proxy

  • Solution: Added environment variables to the Primary service: 

    N8N_PROXY_HOPS=1
N8N_TRUST_PROXY=true

Issue 2: Redis/Postgres Connection Loss → DNS_PROBE_FINISHED_NXDOMAIN

  • Cause: A pinned workflow was causing instability in the Redis/Postgres connections, which made the service appear offline (DNS error)

  • Solution: Unpinned the problematic workflow

Both issues are now resolved. The service is stable.

Thanks for the support resources — leaving this here in case it helps others with similar symptoms.

brody
EMPLOYEE

3 months ago

This thread has been marked as public for community involvement, as it does not contain any sensitive or personal information. Any further activity in this thread will be visible to everyone.

Status changed to Open brody • 3 months ago

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