Paraview v6.0.1 in Linux shows: vtkXOpenGLRenderWindow.:1458 WARN| bad X server connection after successful connection

ParaView Support
1

After installing Paraview v6.0.1 on our Linux HPC environment and running in client/server mode, we get the Warnings shown in the server-side logs shown below. The GUI running on the client shows the same Warning. Other than what those show, it appears that everything is running correctly. We are operating in a headless environment where X11 Forwarding is not configured. Also, no GPUs are on either the client, server, or HPC compute nodes. We did not see these warnings with v5.13.1.

From server-side output file:

Connecting to client (reverse connection requested)…
Connection URL: csrc://MYserver.ray.com:11111
Client connected.
(  11.226s) \[pvserver.67     \]vtkXOpenGLRenderWindow.:1458  WARN| bad X server connection. DISPLAY=
(  11.226s) \[pvserver.73     \]vtkXOpenGLRenderWindow.:1458  WARN| bad X server connection. DISPLAY=
(  11.226s) \[pvserver.87     \]vtkXOpenGLRenderWindow.:1458  WARN| bad X server connection. DISPLAY=
(  11.226s) \[pvserver.46     \]vtkXOpenGLRenderWindow.:1458  WARN| bad X server connection. DISPLAY=
(  11.226s) \[pvserver.50     \]vtkXOpenGLRenderWindow.:1458  WARN| bad X server connection. DISPLAY=
(  11.226s) \[pvserver.53     \]vtkXOpenGLRenderWindow.:1458  WARN| bad X server connection. DISPLAY=
(  11.226s) \[pvserver.55     \]vtkXOpenGLRenderWindow.:1458  WARN| bad X server connection. DISPLAY=
(  11.226s) \[pvserver.56     \]vtkXOpenGLRenderWindow.:1458  WARN| bad X server connection. DISPLAY=
(  11.226s) \[pvserver.57     \]vtkXOpenGLRenderWindow.:1458  WARN| bad X server connection. DISPLAY=
(  11.227s) \[pvserver.59     \]vtkXOpenGLRenderWindow.:1458  WARN| bad X server connection. DISPLAY=
(  11.226s) \[pvserver.60     \]vtkXOpenGLRenderWindow.:1458  WARN| bad X server connection. DISPLAY=
(  11.226s) \[pvserver.62     \]vtkXOpenGLRenderWindow.:1458  WARN| bad X server connection. DISPLAY=
(  11.226s) \[pvserver.64     \]vtkXOpenGLRenderWindow.:1458  WARN| bad X server connection. DISPLAY=
(  11.227s) \[pvserver.65     \]vtkXOpenGLRenderWindow.:1458  WARN| bad X server connection. DISPLAY=

We are running pvserver using a SLURM submit script with the following arguments:
srun --mpi=pmi2 --cpu-bind=cores --export=ALL -n 96 pvserver --force-offscreen-rendering --system-mpi --timeout=60 --sp=11111 --rc --client-host=MYserver.ray.com

2

I’m curious: does forcing the offsreen mesa rendering mode by setting the environment variable VTK_DEFAULT_OPENGL_WINDOW to vtkOSOpenGLRenderWindow then running pvserver prevent the warnings?

Background: on Linux, ParaView 6 and later attempts to load X11 if it is available, EGL if X11 is available, and then falls back to offscreen mesa if neither of those are available. If your system has X11 libraries installed, but your system is not configured to provide X, that may be causing these warnings.

3

This is indeed the expected behavior when running with the env var or without the --opengl-window-backend option.

I think this is an issue, the check should be silent.

@jaswantp

4

Thank you, guys. That worked. I just put the following entry in my SLURM submit script and the Warning no longer shows up:
export VTK_DEFAULT_OPENGL_WINDOW=vtkOSOpenGLRenderWindow