Http/3 issues

Questions
1

We installed a self hosted n8n instance (1.113.3) behind Traefik Reverse proxy. When activating http/3 on Traefik n8n loses connection when entering a workflow. It just says “no connection”.
There is no error message in the console and no error in Traefik logging. Any advice?

1 Like
2

Hello evo.fin, welcome to n8n Community! I’ll try my best to help yaa

I see the problem is n8n’s editor uses WebSockets (socket.io). HTTP/3/QUIC doesnt support WebSockets. With Traefik H3 enabled, the browser negotiates H3 and the WS upgrade fails “no connection“.

You can try first to disable HTTP/3 for the n8n router (keep H3 elsewhere). TLS option that removes h3 from ALPN for n8n.

tls:
  options:
    no-h3:
      alpnProtocols:
        - "h2"
        - "http/1.1"

Labels:

traefik.http.routers.n8n.tls.options=no-h3@file

You can try it first, and i hope this will works! :blush::raising_hands:

2 Likes
3

Hello, and thank you very much for your help and the warm welcome!

You’re right, I hadn’t considered that. Does n8n support WebTransport in any way instead of WebSockets?

4

Unfortunately, n8n doesnt support WebTransport

The editor uses socket.io over WebSockets, and socket.io in n8n is wired for H2/H1, not WebTransport/QUIC. So even if Traefik speaks HTTP/3, the app wont.

Maybe there are several you can do:

  • Keep HTTP/3 enabled globally if you want, but force n8n’s route (or just the WS endpoints) to H2/H1 via ALPN.
  • Minimal Traefik fil (file provider):
tls:
  options:
    no-h3:
      alpnProtocols:
        - "h2"
        - "http/1.1"

and on the n8n router:

traefik.http.routers.n8n.tls.options=no-h3@file

Maybe you can try it, and i hope it will work fine.

5

Many thanks @Naufal_Fayyadh , your solution worked pretty well for me :grinning_face:

1 Like
6

You’re welcome, have a good day!

7

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