Thanks for the info, Uli.
I ran a few tests and see the issue is GUI related in our case. It seems to speak to the 2nd reason for sleep you described regarding the sending of pixmaps.
I ran two MATLAB scripts. Both including the same steps. However, 1 script suppressed pop-windows tracking the script status. The 2nd script did not suppress the pop-up windows displaying real-time status. The 1st script involving command lines ran in the same amount whether the session was active or suspended. No reduction of time or CPU usage. The 2nd script took much longer and CPU was reduced significantly while the session was suspended.
A few questions:
- for X2GO_NXOPTIONS="sleep=0", what does 0 represent in time. If I set the value to 1000, what would that mean?
- Is the idle-nice-level=19 for suspended sessions the default setting?
- Would the supernicer setting override the x2goagent sleep option setting?
- What would be an example command for the -irlimit option in x2goagent.options file.
h
From: Ulrich Sibiller <uli42@gmx.de> Sent: Monday, June 1, 2020 5:22 PM To: h i <qpile117@outlook.com> Cc: x2go-user@lists.x2go.org <x2go-user@lists.x2go.org> Subject: Re: [X2Go-User] Suspending sessions causes performance slowing down
On Mon, Jun 1, 2020 at 5:51 PM h i <qpile117@outlook.com> wrote:
By how much does the load reduce? I tried again over the weekend, and a typical 5 minute process now takes 3 hours during a suspended session. Is this normal or is there some underlying issue? Did this type of behavior occur under freenx? Just don't recall this type of reduced speed while suspending a session on the client side and running something overnight. I've recently installed a Windows update on the client side and updated our ubuntu 18.04 LTS server with mate DE. Any input would be appreciated. Thanks.
I cannot give you a percentage. It depends on the workload. There are two locations where the nxagent will sleep before going on: The first is where the nxagent waits for input by his clients or the real X server and the second one is when clients are sending pixmaps to the nxagent. Here the sleep depends on the size of the pixmap. Bigger pixmap, longer sleep.
So sessions with a higher percentage of pixmap operations are slower than others.
This behaviour was added in June 2016 between 3.5.0.28 and 3.5.0.29 (commit 6051dec4a1ae6decd9123a3310098baf43f45c49). So if it was active with freenx depends on what version of nx-libs your were using with freenx.
Uli