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

5 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?

Solved$10 Bounty

1 Replies

pedroandriani
PROOP

5 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.


Status changed to Open medim about 2 months ago


Status changed to Solved medim about 2 months ago


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