Unable to launch programs ~18 hours post reboot

[Ken]

I have had a ongoing problem where programs fail to start once my machine has been active for 18 to 24 hours. A reboot corrects the problem but it will reoccur once the waiting period has passed. I reported this under bug # 1354929 but received no response. I've been using Ubuntu for about 6 months so I'm still learning and this is the first bug I've tried to report.

Running 14.04 with all maint current. Hardware is a IBM ThinkCenter 8213 with 2GB ram, 64GB SSD primary, 1 TB data area (which is a windows formatted drive via USB and external case). Dual monitors (one running off a graphics card, the other running off motherboard).

Symptom Details:
Following a boot of the machine, all software functions as it should. All programs start fine, no issues. After an extended idle time (I have no time limit set for session, so it doesn't even lock the screen or logout), when I attempt to start a program it will fail to launch. This behavior is the same for all applications - Thunderbird, Firefox, Libre Office, Wine installed programs, Rythymbox, Terminal. No error messages are presented. All that occurs is the cursor switches to the waiting clock for 6-8 seconds then returns to a pointer. All currently open applications function normally with one exception. If I use an open Firefox window to go to YouTube, it will not initialize the video box.

I've been researching how to get this reported (since my first attempt did not garner any interest). I discovered ubuntu-bug. So I started a new tactic. Following a reboot, when things are working well, I open a terminal, a gedit window, and a firefox window containing a number of tabs containing the bug reporting pages I have found. Once the failure occured, I went to the open terminal and issued ubuntu-bug unity. The following occured in the terminal:
ken@OurVeranda-Linux2:~$ ubuntu-bug unity
Maximum number of clients reached
** (apport-gtk:13395): WARNING **: Could not open X display

(process:15687): GLib-CRITICAL **: g_slice_set_config: assertion 'sys_page_size == 0' failed

A prior event generated a large number of messages indicating something about a key failure in apport-gtk. That is why I setup the gedit window, so that I could save those messages.

Attempted workarounds (other than a reboot):
Logging off and back on does not work.
Starting programs from the terminal window does not work.
Trying to start programs from the search panel (as opposed to attempting to start from the task bar) does not work.

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: unity 7.2.2+14.04.20140714-0ubuntu1.1
ProcVersionSignature: Ubuntu 3.13.0-34.60-generic 3.13.11.4
Uname: Linux 3.13.0-34-generic x86_64
ApportVersion: 2.14.1-0ubuntu3.3
Architecture: amd64
CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins'
CurrentDesktop: Unity
Date: Mon Sep 1 12:25:20 2014
InstallationDate: Installed on 2014-05-24 (100 days ago)
InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Release amd64 (20140417)
SourcePackage: unity
UpgradeStatus: No upgrade log present (probably fresh install)

[Stephen M. Webb (bregma)]

The key clue here is the following error message.

   Maximum number of clients reached

This is a message that the X11 server is no longer accepting connections, usually because its resource database is full. This can be caused by malfunctioning software that asks the X11 server to load resources, but does not properly ask for them to be freed. That cause would be consistent with the symptoms you describe, although logging out from the desktop session kills the X11 server so it should resolve the problem.

I would suggest the next step for you is to install the xrestop package and run that program in a terminal window when starting a session, monitoring its output from time to time. This should give you an idea of which application might be grabbing and not relinquishing X resources.

[Ken (a-launchpad-com-kensbiz)]

Thanks for the suggestion & I'll do that and respond back with results.

[Ken (a-launchpad-com-kensbiz)]

A number of interesting things have happened. First, as requested, I ran xrestop. This revealed a number of tasks under <unknown> that kept increasing in number, as predicted. To try and figure out what was creating these, I rebooted and only opened the terminal with xrestop. These <unknown> tasks began to appear with nothing other than the terminal running. So I looked for tasks that I could easily stop. Wallch, a wallpaper changer, was one I could control. After stopping Wallch, the <unknown> tasks quit increasing. I rebooted to clean things up and all stayed functional for several days. Reactivating Wallch brought back the problem.

Contacting Wallch, they had me upgrade from 4.00 to the latest release 4.16. Now the application fail to launch symptom is gone (as near as I can tell), but the <unknown> tasks continue to appear, adding one in most instances of a wallpaper switch. With the launch issue no longer appearing, the number of <unknowns> has grown to MUCH larger quantities than before, probably because I've not been forced to reboot as often. Pursuing with Wallch support.

I also have noticed that just prior to an added <unknown> task, the nautilus task increases storage by 12141K in both the pxm mem and total columns. And then the <unknown> task is created with essentially the same amount - 12140K - and the nautilus task returns to it's prior storage usage.

[Ken (a-launchpad-com-kensbiz)]

An update - In the above post I stated that the nautilus task was showing the memory bump and release. Upon another reboot and rerun of xrestop, the task Desktop is in the same slot as nautilus was before, no nautilus task now. But the Desktop task is doing the same behavior.