I have installed Ondemand 3.0.1 on one of my test cluster OOD servers and I am getting this error when launching an interactive desktop from that new OOD servers. I can launch it on another test server running Ondemand 2.0.31. What should I look for? I am using pretty much the same ood-portal.yml …

Yes on RHEL8 the EPEL it is python3-websockify and version 0.11.0 works. I just had to update the server to the same version.

Maybe there’s a websockify version mismatch. We run websockfiy 0.8.0 with no issue. Did the compute node you’re getting these jobs on change as well or are the compute nodes the same for OOD 3.0 and 2.0?

They are the same version. We have not upgraded the websockify version.

The version we are running is also 0.8.0 on the compute nodes.

Maybe there’s a cache issue? Can you try in a private window?

Same thing happens with a private window. I can see that the websocket is there in the haproxy log file when I try to connect to it.

Maybe it does have something to do with the response header I have above when I refresh the screen: 400 Client must support ‘binary’ or ‘base64’ protocol

I’ve modified the websock.js file to change: open(uri, protocols) { this.attach(new WebSocket(uri, protocols)); } to: open(uri, protocols) { this.attach(new WebSocket(uri, [‘binary’, ‘base64’])); } But I can’t seem to get the new code to run except in private window but it does start the web…

Yes I just did that. So why do I have to modify the protocols to start a new websocket in 3.0.1 and not the earlier 2.0.x versions?

I am running the latest version of RHEL 8 with the latest OS updates as of two weeks ago and it is a fresh install of the OS and Open Ondemand 3.0.1.

noVNC Failed to connect to server (ondemand 3.0.1)

Get Help

Topic		Replies	Views
Websockify novnc - failed to connect to server - 400 error Get Help	4	350	December 9, 2024
Open OnDemand - Unable to start bc_desktop session (Failed to connect to server) Get Help	7	453	May 12, 2024
noVNC- failed to connect to server Get Help	14	2013	August 1, 2023
Authentication failed / Client temporarily blocked errors when connecting to a running session Get Help question	13	183	November 23, 2025
noVNC failed to connect to server Get Help question	5	3073	May 26, 2022

noVNC Failed to connect to server (ondemand 3.0.1)

Related topics