"Maximum number of clients reached"

Status changed to 'Confirmed' because the bug affects multiple users.

Makes two.. I've got the same problem

This has something to do with the fact that I have a script running in the background that changes my background image every couple minutes. When I disable that script, the problem goes away.

If that script is provided in an official Ubuntu package, please:

1. Change the package from xorg to that one.
2. Set its status to "confirmed".

Thank you.

It's a script I wrote myself. I would be happy to share it if that would be useful.

I do not understand why you marked this issue invalid.

Surely you are not meaning to suggest that it is invalid for users to write their own tools which periodically change the desktop background using the interfaces that are provided for doing exactly that?

This bug has been reported over and over again since it was introduced in 12.04 (just do a LP search for "Maximum number of clients reached"). Now, for some reason in 15.10 it's much easier to reproduce. I hit the problem every day now, whereas I used to be able to go a couple weeks without hitting it. There are many clues in the older reports:

https://bugs.launchpad.net/ubuntu/+source/gnome-screensaver/+bug/263211 seems to have gotten the most attention, and was closed with changes to gnome-screensaver, but I don't think that actually fixed the problem (just made gnome-screensaver quit making the problem show up). It seems to be some kind of X resource leak.

I don't know if this is relevant or helpful, but taking some of the comments from that bug report, here are some of the things folks did in that bug to troubleshoot:

xwininfo -root -children | wc -l

Over time, the resulting number keeps going up. It's currently at 430, and if I open a window (gcalc, for example), I'll get the "Maximum number of clients reached" error when trying to run xwininfo. If I look at the out put of xwininfo -root -children right before that, I see that about 80% of the windows have no name.

Also, if I run xrestop, I get a whole bunch of "<unknown>" resources with no associated PID (218 of them at the moment). The other 38 are actual windows I have open.

A little more info, as I've been trying to watch the output of xwininfo -root -children, as well as xrestop over time.

As I mentioned before, the number of root children keeps growing over time. It starts out under 100, and grows over time. When the "Maximum number of clients reached" problem started this time, it was at 322 (lower than last time). However, I also watched the output of "xrestop -m 1 -b | grep ^[0-9]" over time, and watched it grow from around 42, to 255 when the problem manifested itself (same as last time). I think this is more significant, because the 255 seems to be a cap, and it never goes higher than this. Is there an 8-bit table somewhere in X that if it fills up, could cause this syptom?

More info: This seems to be related to Unity, or at least, Unity makes the problem show up a lot faster. When running Unity, I'd see this problem every day. I switched to using gnome-shell for my desktop, and I've been up for a week now without ever encountering the problem.

If you experience this bug using a different compositor than Compiz, please change the affected package back from "compiz" to "xorg".

I have been having this problem for a while. I have seen a number of commands suggested as helpful in various forums: `xwininfo -root -children`, `xlsclients`, and `lsof -U`. I wrote a script that logged the number of lines reported by these every 30 seconds.

It took about 5 days for my computer to crash (for most of which the computer was idle because I was away for the long weekend). xlsclients and lsof stayed steady at around 20 and 500 lines respectively. xwininfo climbed steadily from 68 to 362. When the computer was idle and locked, it would stay steady for hours at a time, then climb by about 10 windows over 5 minutes, then steady out again. As described by Brett Johnson above, most of the windows have no name.

I notice that it is always nautilus that crashes, usually while the computer is unattended. I will return, nautilus will be closed and I won't be able to open any new windows because the maximum number of clients is reached. Nautlius exits with a segfault some address "not located in known VMA region".

Experienced this with Ubuntu 16.04 after using my work desktop station as a temporary server with vagrant servers and using gnome-shell as my DE for about a month. Nautilus started to crash with the error:

cannot open display: :0.0
Maximum number of clients reached

Restarting gdm3 didn't work either. Killed all users, and run startx as root launched the gnome-shell and nautilus worked, but I could not make gdm3 start as gdm3 user again.

Also experiencing this currently on Ubuntu 16.04.5 LTS.

After working on the computer for a few hours, I can no longer open any application (Nautilus, Terminal, etc).

If I already had a terminal open before the issue occurs and I try to start nautilus from this old terminal, I get the following error:

Maximum number of clients reached
** (nautilus:29162): WARNING **: Could not open X display
sys:1: PyGIWarning: Nautilus was imported without specifying a version first. Use gi.require_version('Nautilus', '3.0') before import to ensure that the right version gets loaded.
/usr/share/nautilus-python/extensions/nautilus-admin.py:18: PyGIWarning: GConf was imported without specifying a version first. Use gi.require_version('GConf', '2.0') before import to ensure that the right version gets loaded.
  from gi.repository import Nautilus, GObject, GConf, Gtk, GLib
** Message: Init Stock Icons
Maximum number of clients reached
(nautilus:29162): GnomeDesktop-WARNING **: Unable to open display ':1' when setting background pixmap

Segmentation fault (core dumped)

I tried all possible solutions that were provided by Google but nothing worked. Restarting the system or closing half of the opened applications (e.g. Chrome tabs) seems to resolve the issue temporarily, but this is not really a solution but a workaround.

Hi there!

Same problem here...

A simple search in the Internet and found several threads about this problem and it seems no one is interested on fixing this... and it is very disappointing to see that this issue is still opened... I'm not an expert in xserver but this seems like a really simple fix in a variable MAXCLIENTS...

I know that an increase in a variable limit may have an impact in system resources, but nowadays every medium laptop should be able to handle such an increase in resource consumption.

My laptop setup is:
 System: Ubuntu 18.04.3 LTS
 Memory: 31,1 GiB
 Processor: Intel Core i7-7820HQ CPU @ 2.90GHz × 8
 Graphics: Intel HD Graphics 630 (Kaby Lake GT2)
 GNOME: 3.28.2
 OS type: 64-bit
 Disk: 491,2 GB

which is pretty much common in development working environments, so it's just not acceptable such an limitation like this.

Please fix this or provide instructions to increase this limit in config files.

Thankx!