New Session Writes in Old Log

[trleith]

Dear xrdp Developers,

I have encountered an issue where a new xrdp session creates an expected log file (/tmp/xrdp-session-trl-<pid>.log), but processes from a prior session (Apr 22 23:46:51 CDT 2025, window manager PID 3894, DISPLAY=:11) continue appending to its log file (/tmp/xrdp-session-trl-3894.log), despite no active PID 3894 (confirmed via pstree 3894). Below is the evidence:

Persistent Processes Writing to 3894.log:

• lsof and ps -aux show processes from the 3894 session holding open descriptors to 3894.log:
  • PID 4032: /usr/bin/python3 /usr/share/system-config-printer/applet.py (stdout/stderr), logged warning:
    /usr/share/system-config-printer/applet.py:366: Warning: Source ID 11 was not found when attempting to remove it
  • PID 4040: /usr/libexec/geoclue-2.0/demos/agent (stdout/stderr).
  • PID 4098: /usr/libexec/tracker-miner-fs-3 (stdout/stderr), spawns tracker-extract-3 processes (e.g., PID 257569) writing GLib-GIO-WARNING messages.
  • PID 4157: pw-cli (PipeWire/xrdp audio, stderr).
• Example from 3894.log:
  (tracker-extract-3:257569): GLib-GIO-WARNING **: 14:50:24.530: Error creating IO channel for /proc/self/mountinfo: Invalid argument (g-io-error-quark, 13)
• All processes started Apr 22 and persist into Apr 23.

Session Management:

• xrdp-sesman.log confirms the 3894 session (session PID 3893, DISPLAY=:11) terminated cleanly on Apr 22 23:59:49:
  [20250422-23:59:49] [INFO ] ++ terminated session: username trl, display :11.0, session_pid 3893
• New sessions (e.g., 257564, session PID 257559, DISPLAY=:12) terminate with exit code 1:
  [20250423-14:54:35] [WARN ] Window manager (pid 257564, display 12) exited with non-zero exit code 1

LightDM Context:

• journalctl -u lightdm shows no activity on Apr 22–23, confirming LightDM was not managing sessions, consistent with light-locker errors:
  (light-locker): ERROR: Environment variable XDG_SESSION_PATH not set. Is LightDM running?

xrdp-sesman Restarts:

• Frequent restarts (e.g., Apr 23 12:25:52, 13:43:53) may disrupt cleanup:
  [20250423-12:25:52] [INFO ] sesman_main_loop: sesman asked to terminate
  [20250423-12:25:52] [INFO ] starting xrdp-sesman with pid 216701

Why do processes like tracker-miner-fs-3 (PID 4098) from the 3894 session (DISPLAY=:11) persist after session termination and append output to 3894.log during new sessions (DISPLAY=:12)? Is this due to incomplete session cleanup, inherited file descriptors, or a logging configuration issue in startwm.sh or xrdp? Any insights would be appreciated. I'm trying to get a stable xrdp/LightDM/xFCE environment going for a new project.

Thank you,
t

xrdp-session-trl-3894.log
xrdp-session-trl-211182.log
xrdp-session-trl-249749.log
xrdp-session-trl-252328.log
xrdp-session-trl-257564.log
lsof_grep_xrdp-session-trl-3894.log
journalctl_-u_lightdm.txt
program_pid_4032.txt
xrdp.log
xrdp-sesman.log
journalctl_-u_lightdm.txt
startwm.sh

[matt335672]

For xrdp v0.9.x, session management doesn't work properly, and you'll have to learn to live with it.

If you're seeing this on xrdp v0.10.x I'm guessing it's related to systemd --user. Systemd starts services on behalf of a user which are considered outside the scope of the session.

As ever, more information can be found on the excellent Arch wiki:-

https://wiki.archlinux.org/title/Systemd/User

Processes will persist if there's anything at all left open for the user (like an ssh login):-

https://bbs.archlinux.org/viewtopic.php?id=235105

[trleith]

Ohhhhh. Yes, v0.9.x,

Thank you very much.

I saw an article very recently (yesterday or the day before) saying Canonical is moving to Wayland entirely in their next major release (25.x) but I've been warned away from it because I'm not really good at any of this, I don't understand the relationship between GNOME and Wayland, and Wayland is new. I don't want to find myself lost, but feeling lost anyway, I'm beginning to wonder about the wisdom of that advice.

My machine (HP ProLiant ML350e Gen8 v2, Xeon E5-2440 v2 X 2 = 16 cores @ 3GHz, 96G RAM, NVIDIA GTX 1060 3G RAM) has vastly more power than the Sparc stations I used a lifetime ago, but by today's standards isn't anything particularly noteworthy. I'm more concerned about network latency than anything because I want X sessions over WAN. "Lightweight on the net" is particularly good, but I do hope I have sufficient machine resources to make it snappy otherwise.

Now that I've got something working at all and have had a little "tour" through X11 again, what's a reasonable next move?

 t

[matt335672]

If you're worried about latency and you're on v0.9.x, have a look at #2910 and #2905, particularly this comment.

At some point we'll need to support Wayland as part of this project, but we're quite a way from that at the moment.

[trleith]

After extensive chasing of proverbial rabbits I think I understand at least how v0.9.x fails (doesn't properly register with systemd-logind, apparently some D-bus issues) and I don't know enough to "fix it" in my startwm.sh. If anybody want a rundown I can probably get something reasonable together. But nobody's working on that version anymore and I think I should move on at least a week ago.

1. I hadn't wanted to get outside the Ubuntu LTS framework because I'm not a "real" sysadmin, but I do want remote sessions, preferably using the GPU, that work. I have occasionally gotten xcfe sessions to work and use the NVIDIA 1060 on xrdp 0.09.x but "live with it" will be too painful. I need something that works.
2. When trying out xrdp v0.1.x I recall missing symbols having to do with moving and/or resizing windows and learned that NVIDIA makes itself hard to work with and that's the source of it, but maybe there was some also kind of mismatch between v0.1.x and other Xorg components. I tossed GNOME in favor of xcfe because I thought I had GNOME problems too. I haven't the expertise to know for sure. I've also got a kernel update rolled back and frozen at the moment, tangled up with all this. I would like to undo that.
3. If I compiled some newer version of xrdp and whatever else I need from Xorg, could I expect it to work with the apparently troublesome NVIDIA 1060? I don't quite know what to look for in the release notes.
4. What updates would I have to freeze so Ubuntu doesn't wreck it and leave me with a month of troubleshooting things I don't understand in the first place? What would I be getting myself into?
5. I`m happy to assist let's say "current development" by running experiments and providing logs, but I need something that works.
6. Is there a reasonable alternative? I'm leery about VNC running into the exact same problems. Somebody mentioned X2Go. Never heard of it before.

[matt335672]

Based on your requirements, using xrdp is going to be problematic for you. If I can summarise:-

1. Ubuntu aren't very good at adopting new versions of xrdp. Other distros are much better. Ubuntu LTS is still using xrdp v0.9.x out-of-the-box. This has issues with systemd sessions that aren't realistically fixable.
2. NVidia-based acceleration for xrdp is very much still a work in progress and hasn't landed in any stable release yet.
3. You're not prepared to spend many days troubleshooting this, and coping with OS updates in the meantime. Don't get me wrong - I think this is a realistic and sensible view of the world. Most of us just want to use computers to get stuff done.

I can't see a simple way forward which will satisfy all of these using xrdp and xorgxrdp. Using xrdp and the VNC backend will not solve 1), but should fix the other 2, provided the performance is acceptable.

The other two suggestions I can give you are:-

1. Try GNOME remote desktop. This gives you a way to share a logged-in console desktop over the network. It's going to give you the most full-featured experience (remote audio, better clipboard, etc).
2. Investigate a simple VNC setup on the LAN and see if the performance and the way of working is acceptable.

If either of these gives you something that works, layer your security requirements on top.

X2Go I can't help you with I'm afraid.

I hope this is at least a bit useful.

[trleith]

Thank you very much.

I do enjoy computer puzzles more than I enjoy crossword puzzles but I've got over 60 hours in this. Yes, I learned a lot but want to get stuff done. I didn't even know there was a GNOME remote desktop -- maybe I've learned enough to make it work. I see it uses Microsoft RDP under the hood; I guess I'll find out whether it has the "RDP or SSH terminal but not both" problem. That really threw me. Would never have thought of it.

Thanks again -- I owe you a couple pints.
t