Maximum number of clients reached

[Frank P. Westlake]

After running in Xfce for a few weeks and hibernating every day I get
the error "Maximum number of clients reached" printed by one or more of
my scripts without the culprit program identifying itself. Searching the
Internet I find many suggestions on how to prevent the error but I could
find nothing on what the cause is. Anyone know the likely causes?

For you would-be programmers, it is wise (and used to be common) to
print the program name with messages sent to standard error so that
errors redirected to log files could be traced. I.e.:

bash: Maximum number of clients reached.

Frank

[John K. Herreshoff]

What does ps -A show you?

John.

--
Using the Cubic at home

[Henrik Carlqvist]

On Fri, 20 Feb 2015 07:18:21 -0800, Frank P. Westlake wrote:
> After running in Xfce for a few weeks and hibernating every day I get
> the error "Maximum number of clients reached"

Are you able to open say 10 more xterm windows? If not, that message
probably means that you have too many windows open. By closing some
windows you will be able to open new ones.

regards Henrik
--
The address in the header is only to prevent spam. My real address is:
hc351(at)poolhem.se Examples of addresses which go to spammers:
root@localhost postmaster@localhost

[Frank P. Westlake]

On 02/20/2015 02:36 PM, John K. Herreshoff wrote:
> What does ps -A show you?

A lot of processes. Are processes clients?

Frank

[John K. Herreshoff]

do they say xterm, or whatever it is that is messing with you? If it were
me, I'd try killing the ones you don't need.

Just a thought.

[Frank P. Westlake]

On 02/21/2015 12:02 AM, Henrik Carlqvist wrote:
> Are you able to open say 10 more xterm windows? If not, that message
> probably means that you have too many windows open. By closing some
> windows you will be able to open new ones.

I had 16 windows open and this Thunderbird reply opened into a 17th. I
then opened an xterm (I normally use Konsole) as an 18th and it gave me
the xterm window with a prompt following the warning "Maximum number of
clients reached". I could not open another xterm but I could open a 19th
window from Thunderbird. One of my scripts runs a popup notifier, so
that might be the source of the error message.

Is a "client" a window, or a process, or a handle of some other type?

Frank

[John K. Herreshoff]

Sorry, Frank, but happy to know that the ps -A is not going to help here.

[Øyvind Røtvold]

"Frank P. Westlake" <frank.w...@gmail.com> writes:

>
> Is a "client" a window, or a process, or a handle of some other type?

It's handle of some other type, an application (process) would
usually only need one connection to a server. The number of
connection a server will handle is usually rather low, eg. 256.

The number ow windows allowable must be much larger; every button in
your application may well have it own window.

You probably have some leakage going on where all these clients are
not visible as windows.

xlsclients will list then, but it's also a client so that might be
interesting.


--
.. Ųyvind - soon to appear in a kill file near you.
.. Ignorance can be cured; stupidity is forever.

[Henrik Carlqvist]

On Sat, 21 Feb 2015 05:57:36 -0800, Frank P. Westlake wrote:
> I then opened an xterm (I normally use Konsole) as an 18th and it gave
> me the xterm window with a prompt following the warning "Maximum number
> of clients reached". I could not open another xterm but I could open a
> 19th window from Thunderbird.

This might still mean that you are close to the max number of Windows to
your X server. But most of all it seems as if you have some login script
which starts a program consuming the limited resource.

Are you using bash, tcsh or some other shell? If you don't know and your
prompt contains a '$' you are probably running bash.

You could try to start another shell in your terminal window, simply at
the prompt type

bash

or whatever shell you are using. Do you get the message again? If so try
to narrow it down by running login scripts manually, something like:

. /etc/profile
. ~/.profile
. ~/.bashrc

or with tcsh:

source /etc/csh.login
source ~/.login
source ~/.cshrc
source ~/.tcshrc

Try to find which script gives the error and then narrow it down from
there!

[Floyd L. Davidson]

Henrik Carlqvist <Henrik.C...@deadspam.com> wrote:
>On Sat, 21 Feb 2015 05:57:36 -0800, Frank P. Westlake wrote:
>> I then opened an xterm (I normally use Konsole) as an 18th and it gave
>> me the xterm window with a prompt following the warning "Maximum number
>> of clients reached". I could not open another xterm but I could open a
>> 19th window from Thunderbird.
>
>This might still mean that you are close to the max number of Windows to
>your X server. But most of all it seems as if you have some login script
>which starts a program consuming the limited resource.
>
>Are you using bash, tcsh or some other shell? If you don't know and your
>prompt contains a '$' you are probably running bash.

This is the right idea, but it's barking up the wrong
tree.

Too many X clients, and the error says it can't open a display. An
X client is any process that opens the X display to request services
from the X Server.

Login shells don't do that.

But an Internet browser does... and that is probably
where the problem lies. Two types of browser usage
might well encourage something like this. Using
multiple browsers under different user names, and having
multiple tabs open. All it takes is one of the tabs
viewing some site that repeatedly runs some script to
open up a new frame in some odd way.

I have had exactly the same thing happening, and have
not figured out exactly the source. But by completely
closing the tabs open to a pair of newspaper it has been
stopped. It seems to be a pop up advertizement one of
them is running.

--
Floyd L. Davidson http://www.apaflo.com/
Ukpeagvik (Barrow, Alaska) fl...@apaflo.com

[Frank P. Westlake]

On 02/21/2015 07:49 PM, Øyvind Røtvold wrote:
> xlsclients will list then, but it's also a client so that might be
> interesting.

It reports 'xlsclients: unable to open display ":0"', following
"Maximum number of clients reached", but 'man xlsclients' taught me what
I was missing: that a client is a user of a display that X-server is
maintaining, roughly. That gives me the basis I needed to get started on
solving this. Thanks.

I notice that at least 'xlsclients' properly identifies itself with its
error message.

Frank

[Frank P. Westlake]

On 02/22/2015 03:22 AM, Henrik Carlqvist wrote:
> This might still mean that you are close to the max number of Windows to
> your X server.

Thanks. I normally start with three screens and about 16 windows, 4 of
the windows are Konsole with a total of about 12 tabs (variable). I
suspect it's related to my use of 'knotify', which I've had to handle
like this:

#!/bin/bash
export $(dbus-launch);
kdialog --msgbox "$@" >/dev/null 2>&1;

Frank

[Frank P. Westlake]

On 02/22/2015 06:23 AM, Floyd L. Davidson wrote:
> ... an Internet browser does... and that is probably

> where the problem lies. Two types of browser usage
> might well encourage something like this. Using
> multiple browsers under different user names, and having
> multiple tabs open.

I have 5 windows of Firefox with a total of 12 tabs, and I was able to
open another Firefox window with two tabs. Thunderbird is also open and
is not having trouble with additional windows. Kate is open and will nor
respond to CTRL-O to open a file.

My visual windows don't change much so I suspect it is 'knotify', which
I launch from three scripts once each day. 'ps -A' shows a bunch of
'kded4', 'kded4 <defunct>', 'kdeinit4', 'klauncher', and 'xfconfd'.

Frank

[Henrik Carlqvist]

On Sun, 22 Feb 2015 05:23:16 -0900, Floyd L. Davidson wrote:

> Henrik Carlqvist <Henrik.C...@deadspam.com> wrote:

>>On Sat, 21 Feb 2015 05:57:36 -0800, Frank P. Westlake wrote:
>>> I then opened an xterm (I normally use Konsole) as an 18th and it gave
>>> me the xterm window with a prompt following the warning "Maximum
>>> number of clients reached".

>> But most of all it seems as if you have some login script
>> which starts a program consuming the limited resource.

> Login shells don't do that.

For most people this is true, but most people do not see this kind of
error in a newly opened terminal Window after the shell is started.

Somehow the shell is trying to start an X client and fails doing so
because too many X clients has already been started. Maybe, but only
maybe there have been to many X clients because shells has been spawning
them. Some of the login files are run every time a new shell is started,
this might include shells wich get started when a script file is run.

[Floyd L. Davidson]

"Frank P. Westlake" <frank.w...@gmail.com> wrote:
>It reports 'xlsclients: unable to open display ":0"', following
>"Maximum number of clients reached", but 'man xlsclients' taught me what
>I was missing: that a client is a user of a display that X-server is
>maintaining, roughly. That gives me the basis I needed to get started on
>solving this. Thanks.
>
>I notice that at least 'xlsclients' properly identifies itself with its
>error message.

It isn't related to the number of windows. Once a
process has opened a display it might use dozens of
windows via that particular display.

The error message from xlsclients just means it is the
first to have a problem, not that it is at all related
to causing the problem.

And looking for something with "ps" doesn't help either,
because all that shows is processes, not Xserver
activity!

And a further hinderance is that killing any process
that is using the Xserver, will free up resources and
allow things to function... for awhile. If only one
instance is made available it won't take long to have
the same problem again.

I guess the trick is to selectively kill processes using
the Xserver, and not restart it until either the problem
reappears even with that process gone, or enough time
goes by to suspect that process was indeed the cause.

As noted in a previous article, I would most suspect web
browsers that are likely to be displaying pop up
advertizements from random sites that you are visiting.

[Frank P. Westlake]

On 02/22/2015 07:02 AM, Henrik Carlqvist wrote:
> Somehow the shell is trying to start an X client and fails doing so
> because too many X clients has already been started. Maybe, but only
> maybe there have been to many X clients because shells has been spawning
> them. Some of the login files are run every time a new shell is started,
> this might include shells wich get started when a script file is run.

Now I understand that. I don't think my login scripts do anything X
related but I'll look.

Thanks.

Frank

[Floyd L. Davidson]

Henrik Carlqvist <Henrik.C...@deadspam.com> wrote:
>On Sun, 22 Feb 2015 05:23:16 -0900, Floyd L. Davidson wrote:
>
>> Henrik Carlqvist <Henrik.C...@deadspam.com> wrote:
>
>>>On Sat, 21 Feb 2015 05:57:36 -0800, Frank P. Westlake wrote:
>>>> I then opened an xterm (I normally use Konsole) as an 18th and it gave
>>>> me the xterm window with a prompt following the warning "Maximum
>>>> number of clients reached".
>
>>> But most of all it seems as if you have some login script
>>> which starts a program consuming the limited resource.
>
>> Login shells don't do that.
>
>For most people this is true, but most people do not see this kind of
>error in a newly opened terminal Window after the shell is started.
>
>Somehow the shell is trying to start an X client and fails doing so
>because too many X clients has already been started. Maybe, but only
>maybe there have been to many X clients because shells has been spawning
>them. Some of the login files are run every time a new shell is started,
>this might include shells wich get started when a script file is run.

The shell isn't the culprit, the error comes from the
use of xterm, which does connect to the Xserver.

[Floyd L. Davidson]

"Frank P. Westlake" <frank.w...@gmail.com> wrote:

If you can login on a VT, they don't do anything with X... or you'd
get lots of error messages every time.

[Frank P. Westlake]

On 02/20/2015 02:36 PM, John K. Herreshoff wrote:

> What does ps -A show you?

Here's a current list of processes with more than one instance by
frequency:

131:kded4
118:kdeinit4
115:dbus-daemon
84:gconfd-2
73:xfconfd
61:klauncher
58:kded4
23:bash
4:konsole
4:agetty
3:udevd
3:java
3:eclipse
2:udisks-daemon
2:thunar-volman
2:jfsCommit
2:hci0
2:gvfsd
2:gam_server
2:firefox
2:bioset
2:acpid
2:Thunar

I wish I knew 'awk'. Here's the script ('replines') that gave me that list:

#!/bin/sh
list=();
while read; do
listlen="${#list[@]}";
found=;
for a in $(seq 0 1 $(( ${listlen} -1 ))); do
z="${list[$a]}";
if [ "${z#*:}" = "$REPLY" ]; then
found="${z%:*}"
list[$a]="$((found+1)):$REPLY";
break;
fi;
done;
if [ -z "$found" ]; then
list[$(( ${#list[@]} ))]="1:$REPLY";
fi;
done;
for a in ${list[@]}; do echo "$a"; done;

And the command line:

ps -A|cut -b 25-|replines|sort -gr

Frank

[Floyd L. Davidson]

"Frank P. Westlake" <frank.w...@gmail.com> wrote:

>On 02/20/2015 02:36 PM, John K. Herreshoff wrote:
>> What does ps -A show you?
>
>Here's a current list of processes with more than one instance by
>frequency:

It doesn't help though, as any single one of those
processes might either have 0 Xserver display
connections, or 200 of them!

What does this show:

xlsclients | wc -l

That gives the current count of X clients. I'm not sure
how high it should be able to go. Mine right now shows
47.

One thought that may or may not work out, is to start
some "throw away" process that uses X, and let it run
until you get the error message. Then kill the process
and immediately run xlsclients to get a list of clients.
I'd do that on one command line to try to prevent
something else from being able to grab that one client
slot made available. Another way might be to run 10 or
20 instances of something (a game, for example). Then
use killall to get them all. That gives at least some
elbow room!

The list produced by xlsclients should show some
inordinate number of clients all to one single process.

Here's a way to make it easy to look at,

xlsclients | cut -d' ' -f1-3 | uniq -c | sort -rn

The highest count process will be at the top, and each
line starts with the number for that process.

You might also just randomly, while using the computer,
do the "xlsclients | wc -l" command and watch for any
unusual increase in the number. If it is usually less
than say 50, any time it hits 100 is something to take
a closer look at.

Or that command could be put into a cron job that adds
to a log file. When the problem occurs, check the last
few entries in the log file to see what was changing.
You'd probably want to add " | head -2" to the command
sequence though, to keep the size of the log file
reasonable.

[John K. Herreshoff]

Floyd L. Davidson wrote:

> xlsclients | wc -l

I love that!!!

Clever thing, that wc :-)

[Frank P. Westlake]

On 02/22/2015 08:43 AM, Floyd L. Davidson wrote:
> xlsclients | cut -d' ' -f1-3 | uniq -c | sort -rn

X clients was 275.

Thanks for 'uniq -c', it does a much better job than that awkward script
I wrote.

Frank

[Floyd L. Davidson]

"Frank P. Westlake" <frank.w...@gmail.com> wrote:

>On 02/22/2015 08:43 AM, Floyd L. Davidson wrote:
>> xlsclients | cut -d' ' -f1-3 | uniq -c | sort -rn
>
>X clients was 275.

Wow, that is a real bunch!

Is there one process doing most of that, or is that reasonably
spread out over many different processes?

>Thanks for 'uniq -c', it does a much better job than that awkward script
>I wrote.

Makes it nice!

[frank.w...@gmail.com]

From floyd:

>>X clients was 275.
>
>Wow, that is a real bunch!
>
>Is there one process doing most of that, or is that reasonably
>spread out over many different processes?

Two of the big ones in my message showing the 'ps -A'
counts -- kded4 is one. I only get three hours of
electricity each day so I'm done with the laptop and on
the Android until about 06-PST Monday. Then I'll look at
those high counts and see if I can figure out what uses
them.

Thanks

[Floyd L. Davidson]

Wow, that's an interesting circumstance! Three hours of
electricity is a bit unusual. Of course in some parts
of the world that isn't odd at all... bush Alaska being
one!

What you need is a small lead acid gell cell battery to
run your laptop via a DC-AC inverter. Charge the
battery during those three hours a day with power, and
run the laptop all day even when the power is off. I
would expect that a motorcycle/ATV battery would run the
laptop for a 24 hours. If not a small marine battery
would. Or, use a car battery and run it for a week!

[Henrik Carlqvist]

On Sun, 22 Feb 2015 06:59:34 -0900, Floyd L. Davidson wrote:
> The shell isn't the culprit, the error comes from the use of xterm,
> which does connect to the Xserver.

The xterm could get trouble to connect to X, but if xterm succeeds and

spawns a shell and that shell in the open xterm writes:

"Maximum number of clients reached"

it seems to me that the shell spawned by xterm has been trying to start
some program trying to connect to X. Maybe it would also be possible to
see traces from that when logging in from console without any DISPLAY
set. But maybe the login scripts has some if-statement checking if there
is any DISPLAY set before trying to launch the program.

One more thing pointing towards bash scripts is the error message
mentioned in the first post in this thread:

"bash: Maximum number of clients reached."

Maybe, but just maybe, some login script is causing the problem. However,
as you say it is not the normal thing to do to start X applications from
login scripts. I think that is reason enough to investigate what kind of
X client is being launched from the login scripts and why.

Your suggestion with xlsclients (with and without piping to wc) is great
to pinpoint which process is consuming windows. While OP still is able to
run xlsclients I would suggest the following command:

xlsclients | sort | uniq -c | sort -n

Which might be able to pinpoint the program causing trouble.

[frank.w...@gmail.com]

From HenrikCarlqvist :

>On Sun, 22 Feb 2015 06:59:34 -0900, Floyd L. Davidson wrote:
>> The shell isn't the culprit, the error comes from the use of xterm,
>> which does connect to the Xserver.
>
>The xterm could get trouble to connect to X, but if
xterm succeeds and
>spawns a shell and that shell in the open xterm writes:
>
>"Maximum number of clients reached"
>
>it seems to me that the shell spawned by xterm has been
trying to start
>some program trying to connect to X.

That's so reasonable it's got to be it, and it reminded
me that I have fortunes enabled. I don't have access to
the Linux machine right now but fortunes is the only
thing I can recall not being normal shell programs. Each
prompt calls a fortune and each invocation of 'su' calls
another.

Frank

[frank.w...@gmail.com]

From frank.westlake:

>I don't have access to the Linux machine right now but
>fortunes is the only thing I can recall not being normal shell programs.

I just remembered that fortunes are also called before X
is started so it's probably something else. I'll look
tomorrow.

Frank

[jeff g.]

fortunes??
which fortunes is that?

[Henrik Carlqvist]

On Sun, 22 Feb 2015 18:13:22 -0800, jeff g. wrote:
> fortunes??
> which fortunes is that?

I suppose this is /usr/games/fortune called by
/etc/profile.d/bsd-games-login-fortune.sh

But I don't think that program tries to connect to any X server.

[Frank P. Westlake]

On 02/20/2015 07:18 AM, Frank P. Westlake wrote:
> bash: Maximum number of clients reached.

This might be the cause of my problem:


<http://slackblogs.blogspot.com/2011/02/x11-maximum-number-of-clients-reached.html>
Update (16 March 2011): This problem has been solved at Slackware-
Current tree. The culprit is the old, obsolete guidance-power-manager
package which was included in Slackware 13.1. Please remove this
package and you will be fine. The drawback of this is that you might
lost some information about battery power. Just use KDE's battery
monitor to track your batteries. I should have mentioned this update
earlier. Sorry for that.

It's been about a year and a half but I recall that when I installed
Slackware 14.1 the battery monitor was not working so I installed
something other than the default monitor. Figuring out how to fix this
problem will take too much of the time I have on the computer so I'll
just leave it and restart X every couple of months. Also, since I don't
have electrical power at home the battery monitor is very important to
me and I don't want to lose the amount of information I now get.

Thanks for the help!

Frank

[jeff g.]

On 02/22/2015 10:47 PM, Henrik Carlqvist wrote:
> On Sun, 22 Feb 2015 18:13:22 -0800, jeff g. wrote:
>> fortunes??
>> which fortunes is that?
>
> I suppose this is /usr/games/fortune called by
> /etc/profile.d/bsd-games-login-fortune.sh
>
> But I don't think that program tries to connect to any X server.
>

That is what I was wondering but if it used for an x-screensaver, say,
it just may do that. I'm not familiar with fortune "the game", per se,
and don't have it as part of my distro, ubuntu based. I am obviously
not a unix or BSD user.

[Helmut Hullen]

Hallo, jeff,

Du meintest am 23.02.15:

>>> fortunes??
>>> which fortunes is that?

> I'm not familiar with fortune "the game",
> per se, and don't have it as part of my distro, ubuntu based.

If installed "fortunes" shows an aphorism after user's login.

See also

http://en.wikipedia.org/wiki/Fortune_cookie

Viele Gruesse
Helmut

"Ubuntu" - an African word, meaning "Slackware is too hard for me".

[jeff g.]

On 02/23/2015 08:55 AM, Helmut Hullen wrote:
> Hallo, jeff,
>
> Du meintest am 23.02.15:
>
>>>> fortunes??
>>>> which fortunes is that?
>
>> I'm not familiar with fortune "the game",
>> per se, and don't have it as part of my distro, ubuntu based.
>
> If installed "fortunes" shows an aphorism after user's login.
>
> See also
>
> http://en.wikipedia.org/wiki/Fortune_cookie
>

Thanks, Helmut, I am aware of the fortune cookie (see below). For me
this is a function of my email client that adds sigs to messages. It
wouldn't occur to me to use it for a login but I can see the
entertainment value on networks - only a unix guy would amuse themselves
like that :)

--
Jeff G.

Health nuts are going to feel stupid someday, lying in hospitals dying
of nothing.

[jeff g.]

On 02/23/2015 10:19 AM, jeff g. wrote:
> On 02/23/2015 08:55 AM, Helmut Hullen wrote:
>> Hallo, jeff,
>>
>> Du meintest am 23.02.15:
>>
>>>>> fortunes??
>>>>> which fortunes is that?
>>
>>> I'm not familiar with fortune "the game",
>>> per se, and don't have it as part of my distro, ubuntu based.
>>
>> If installed "fortunes" shows an aphorism after user's login.
>>
>> See also
>>
>> http://en.wikipedia.org/wiki/Fortune_cookie
>>
>
> Thanks, Helmut, I am aware of the fortune cookie (see below). For me
> this is a function of my email client that adds sigs to messages. It
> wouldn't occur to me to use it for a login but I can see the
> entertainment value on networks - only a unix guy would amuse themselves
> like that :)
>

Being a smartass on NNTP can bite you - I'd like to back off that last
remark - I can see a real use for things like MOTDs, etc. on a network...

[Ed Wilson]

Floyd L. Davidson wrote:


>
> What you need is a small lead acid gell cell battery to
> run your laptop via a DC-AC inverter. Charge the
> battery during those three hours a day with power, and
> run the laptop all day even when the power is off. I
> would expect that a motorcycle/ATV battery would run the
> laptop for a 24 hours. If not a small marine battery
> would. Or, use a car battery and run it for a week!
>

Is there any reason you want to put an inverter inline? HP, Dell, and
several third parties make auto adapters designed to run off 12 volt power
outlets commonly found in cars.

As long as I am spending money that is not mine, solar panels and charge
controllers can help keep the car battery topped off.

Ed Wilson

[Floyd L. Davidson]

Oh that's perfectly fine too! The inverter can be used
for other things too though. Most if maybe not all
could also be found in 12 volt versions, but that also
adds complexity. I just find the inverter to be the
most flexible.

[Unknown]

====
That's wildly over optimistic.
Being located in DEgeneration new "democratic" South Africa I can speak
from experience -- which is only trumped by valid calculations.

Electricity generating systems, unlike bank-robbers, prefer to work 24/7.
The reason for 3-hour-supply is usually that the constant-maximum supply
is ROTATED between client-locations. So with consumers running at full
blast WHEN it's their turn, the situation is worse. Eg. running your
device from stored/accumulator electricity has substantial conversion
losses.

Which is where perhaps android comes in:
IMO the american "infinite frontier"/wastefull culture, has promoted the
WinTel power-hog; which prompted me to investigate rPi.
AFAIK android is ARM-based.
rPi allows me to listen to the TextToSpeech inet-fetched-files in a
location which has no electricity supply. But the 4*4*4inch 6V. Acco
only lasts for ca. 3 hrs. rPi averages 300mA x 5V = 1.5 Watt; with
no display/keybrd. The WinTel [atom CPU: minimum WinTel consumption]
that I had stolen, even needed a cooling fan.

Perhaps I should check if my Acco is rated at only:3 x 300mA ~ 1 AmpHour?