[X2Go-User] Long-running x2goagent, high memory usage

[Johannes Töger]

Thanks for quick reply.

Answers to your questions below. I hope it gives some clue. Please let me know what else I can try.



What version of x2goagent resp. nxagent are you using? dpkg -l nx-libs?

	dpkg -l nx-libs: no packages found <--- this seems strange?

	x2goserver-x2goagent 4.1.0.3-0~1708~ubuntu1 amd64
	nxagent 2:3.5.99.20-0~20190425 amd64  

Can you please run xrestop within such a session and check if there are numbers that are far away from those of a fresh session?

	Nothing out of the ordinary there I think. No processes with high memory usage.

You probably cannot answer that due to your usage scenario, but
anyway: does this also happen when you do not disconnect/reconnect?

	I'll try to think of a way to test this.

What are you running inside the session?

	No real pattern here for good and bad sessions. Matlab, Python/machine learning stuff, NVIDIA CUDA-accelerated machine learning programs etc.

— 
Johannes Töger

Associate Senior Lecturer
Cardiac MR Group
Department of Clinical Sciences Lund, Clinical Physiology
Lund University, Sweden

-----Original Message-----
From: Ulrich Sibiller <uli42 at gmx.de> 
Sent: Friday, January 17, 2020 13:25
To: Johannes Töger <johannes.toger at med.lu.se>
Cc: x2go-user at lists.x2go.org
Subject: Re: [X2Go-User] Long-running x2goagent, high memory usage

On Fri, Jan 17, 2020 at 11:56 AM Johannes Töger <johannes.toger at med.lu.se> wrote:
> We are using x2go for a common compute server at our department. We have users both on the local LAN and connections to the other side of Europe that work really well. Being able to close the client and have computations still running in a GUI environment is great.
>
> However, I think we have encountered a bug. Some (but not all) of the long-running x2goagent processes start taking a lot of memory, ~30 GB. This adds up quickly so that the other users can’t do their work. Below you can see how user3 and user7 have x2goagent processes with large memory use (RSS column).
>
> How can I go about debugging this? I have quite a bit of Linux experience, but I don’t know where to start on this one since I don’t know much about how x2go works internally.
>
> Server is on Ubuntu Server 18.04.1 LTS, (x2goserver 4.1.0.3-0~1708~ubuntu18.04.1). Clients are on Windows 10, version. 4.1.2.0.
>
> johannes at compute-server:~$ ps  -o pid,lstart,rss,user $(pgrep 
> x2goagent)

What version of x2goagent resp. nxagent are you using? dpkg -l nx-libs?

Can you please run xrestop within such a session and check if there are numbers that are far away from those of a fresh session?

You probably cannot answer that due to your usage scenario, but
anyway: does this also happen when you do not disconnect/reconnect?

What are you running inside the session?

You could run x2goagent with valgrind to identify memory leaks but I am unsure if that is working on a stock installation ( I don't do the packaging for Debian/Ubuntu so I don't know if the deliveres binaries allow for decent analysis/output). I'll check that this weekend.

Uli