Hello!

 

I probably detected strong problems with x2go, not very easy to explain.

I am running a debian bullseye desktop, on it a kvm guest with debian

bullseye, both have kernel6. The kvm guest x2goserver: 4.1.0.3-5, the

host (my workstation) x2goclient: 4.1.2.2-2. Usually everything updated.

 

The problem is the performance of firefox, but not generally. It stucks

sometimes, up to several minutes and is completely unresponsive,

especially(!), if it comes to youtube videos, but most time, it is not

video.

Astoundigly, in the many cases, it recovers. I am run dstat permanently

(in the guest) and usually see a memory bottleneck (mem < 1 GB), not

too strong and additionally high cpu usage, load: 6/4/4, but not too long.

Often, this box crashes, if mem goes below 500 MB. Known, with firefox.

 

For unknown reasons, this situation is not stabil (I am using up to

500 Tabs), one will never know, when this may happen and pre-actively

saveing the session and continue with, say, 50 Tab, doesnt change the

problem!

 

The VM got 8 cores(!) on a AMD EPYC-Rome Processor with max 3.4 Ghz

and 24 GB(!) mem, it got two network interfaces, one, to communicate with

my host over a local bridge (10-36 Gb/s!), this is the "x2go-channel" and

a lan-IF (1 Gb/s, hardware-passthrough) to the gateway (has 500 Mb/s) and

nothing overloaded ever. Additionally some diskwrite, but with 600MB/s

(in the VM!) this should not indicate a bottleneck.

 

But since days, while another hickup, I saw, that the fox needs about

only 20% cpu, BUT 'x2goagent' neds 100% !! It looks like the hickup

appears exactly at those times. I setup a little processmonitor for the

x2goagent and this seems to show a memory leak. I append this at the

end. I installed 'glances' and that show me the x2goclient as the second

mem consumer, growing.

What language is the x2goagent written? Looks like a failing

heap-management, garbage collection, which needs a lot of cpu?

 

Some notes would be really welcome!

 

Thanks,

Manfred

 

--- x2go-"monitor" -----------------------------------

(to keep this short, it has been cutted in the middle)

 

$ while true; do ts="$(isodate -dt)"; xp="$(ps --no-headers -o user,pid,rss,%mem,comm -p 9430)"; echo "${ts}  ${xp}"; sleep 3600; done
2023-04-05--22-21-29  ncu1        9430 1479916  6.0 x2goagent
2023-04-05--23-21-30  ncu1        9430 1491476  6.0 x2goagent
2023-04-06--00-21-30  ncu1        9430 1507612  6.1 x2goagent
2023-04-06--01-21-30  ncu1        9430 1514504  6.1 x2goagent
2023-04-06--02-21-30  ncu1        9430 1545784  6.2 x2goagent
2023-04-06--03-21-30  ncu1        9430 1560096  6.3 x2goagent
2023-04-06--04-21-30  ncu1        9430 1664844  6.7 x2goagent
2023-04-06--05-21-30  ncu1        9430 1684888  6.8 x2goagent
2023-04-06--14-06-28  ncu1        9430 1684888  6.8 x2goagent

.......

2023-04-10--16-06-31  ncu1        9430 2263236  9.1 x2goagent
2023-04-10--17-06-31  ncu1        9430 2274848  9.2 x2goagent
2023-04-10--18-06-31  ncu1        9430 2305704  9.3 x2goagent
2023-04-10--19-06-31  ncu1        9430 2352964  9.5 x2goagent
2023-04-10--20-06-32  ncu1        9430 2352964  9.5 x2goagent
2023-04-10--21-06-32  ncu1        9430 2406988  9.7 x2goagent
2023-04-10--22-06-32  ncu1        9430 2446112  9.9 x2goagent

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