Having issues with blank expose windows

[MickM]

I use NoMachine to connect to a Linux box to display back individual windows (of Cadence EDA software) instead of the remote desktop on my Mac. Part of the greatness in doing this was that I could do Expose on my Mac and pick/choose the remote window I wanted very quickly instead of continuously moving around Linux windows on the Linux desktop searching for the window I wanted. I believe my issue occurred with the last update to 6.9.2 (although I believe I upgraded directly from 6.7.x) – now when I do Expose many of the remote windows show blank or partially blank contents (the local Mac windows are fine) and I can no longer tell which remote window is which. When that happened I was running High Sierra, and I’ve since upgraded to Catalina and the problem still persists. If I select a blank remote window it comes to the front and then it redraws so I can fully see it’s contents and if I do another expose event then that window now does show it’s contents during the expose event. I can pick all the blank windows one by one and bring them to the front and eventually expose with show all the usual contents. The amount of gray in the window during expose also appears to be a function of how much the window was overlapped by other windows. Note also that it’s only the remote windows that are being rendered by X11 on the Mac that have this behavior.

Here are some further details:

NoMachine 6.9.2 running on a mid-2015 MacBook Pro with 10.15.3. The remote machine is a HP ProLiant ML10 Gen9 running Centos 6.9

 

[fra81]

Hi MickM,

I couldn’t reproduce with a similar setup, but probably I’m missing something. Could you send a video showing the problem?

[MickM]

I’d be happy to provide you with a video, but it’s 2020 already and the TINY 1MB limit on file size attachments isn’t working for me. After recording my screen for about 30 seconds highlighting the issues my video is 80MB. I tried compressing it and got down to 12MB but some of my menu commands now are too blurry to read. Memory so cheap these days so it’s very frustrating to bang into these limits. Do you have an alternate way for me to get you the file.

In other news, I’ve noticed that NoMachine will often disconnect while unattended and start itself up again seconds later. I believe that when that occurs all the covered windows show as blank (or nearly blank) during an expose event. You have to manually select each window to refresh the view so that subsequent expose events show their contents during the expose. Hopefully that’s another clue.

[Britgirl]

You can share a link with us to a file-sharing service – send the link to us privately via forum[at]nomachine[com] and we’ll download it.

[MickM]

I had sent a link to a video of the expose issue in a separate email to you a week ago and haven’t heard anything back. I continue to be suspicious that this is all connected to NoMachine possibly disconnecting and then reconnecting by itself, with a residual side effect that the Expose window images are subsequently lost. I asked the guy who installed the patched version onto the linux box if there were any NoMachine disconnection logs I could forward to you, but he wasn’t sure where to look…

[fra81]

Yes, it must be the disconnections.

I’ve seen the video (thanks for sending it) and that is what I would expect in case of disconnection. Local windows are destroyed and so their content, saved locally, is gone. Upon reconnection, only not overlapped content will be rendered and sent. This is how X applications (connected to the same X display) work and we can’t change this.

Now it would be interesting to investigate these disconnections. Client side logs can be gathered as explained in https://www.nomachine.com/DT10O00163#2. Also server side logs could be useful. To gather them now you can follow instructions in https://www.nomachine.com/AR10K00697.

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