krdc vnc becomes extremely slow after a few seconds

Bug #792251 reported by Dennis Schridde
12
This bug affects 2 people
Affects Status Importance Assigned to Milestone
KDE Network
Invalid
Medium
kdenetwork (Ubuntu)
Confirmed
Undecided
Unassigned

Bug Description

Binary package hint: kdenetwork

After a few seconds into a vnc connection it will become very slow. The cursor follows the mouse hardly, until it stops almost completely (and/or updates only after tens of seconds) and mouse/key presses will only have an effect after minutes. In addition the visible area is only updated very very slowly: I first see half of the screen, then a few blocks more, and after some minutes the full screen, until the process starts freshly.

ProblemType: Bug
DistroRelease: Ubuntu 11.04
Package: krdc 4:4.6.2-0ubuntu3
ProcVersionSignature: Ubuntu 2.6.38-8.42-generic 2.6.38.2
Uname: Linux 2.6.38-8-generic i686
Architecture: i386
Date: Fri Jun 3 10:40:12 2011
InstallationMedia: Kubuntu-Netbook 10.04 "Lucid Lynx" - Beta i386 (20100318)
ProcEnviron:
 PATH=(custom, user)
 SHELL=/bin/bash
SourcePackage: kdenetwork
UpgradeStatus: Upgraded to natty on 2011-04-28 (35 days ago)

Revision history for this message
Dennis Schridde (devurandom) wrote :
Revision history for this message
Dennis Schridde (devurandom) wrote :

P.S: This appears to be a bug in KDE, since gvncviewer (using gtk-vnc) is extremely fast. The network connection is 1Gbps Ethernet.

Changed in kdenetwork:
importance: Unknown → Medium
status: Unknown → New
Revision history for this message
In , Dennis Schridde (devurandom) wrote :

Version: unspecified (using KDE 4.6.2)
OS: Linux

After a few seconds into a vnc connection it will become very slow. The cursor follows the mouse hardly, until it stops almost completely (and/or updates only after tens of seconds) and mouse/key presses will only have an effect after minutes. In addition the visible area is only updated very very slowly: I first see half of the screen, then a few blocks more, and after some minutes the full screen, until the process starts freshly.

The downstream Ubuntu-bug #792251 is at https://bugs.launchpad.net/ubuntu/+source/kdenetwork/+bug/792251 , providing more information on installed software.

Reproducible: Always

Revision history for this message
In , Dennis Schridde (devurandom) wrote :

P.S: This appears to be a bug in KDE, since gvncviewer (using gtk-vnc) is extremely fast. The network connection is 1Gbps Ethernet.

Revision history for this message
In , Uwolfer (uwolfer) wrote :

Can you please check if there is high CPU load when KRDC gets slow? Memory ussage?

Revision history for this message
In , Dennis Schridde (devurandom) wrote :

CPU utilisation is at maximum (2.6GHz AMD Athlon64 X2) and memory usage is VIRT:375M RES:32M SHR:22M (retrieved via htop).

Revision history for this message
In , Uwolfer (uwolfer) wrote :

Can you reproduce this issue all the time? Do you have a slow connection?

Revision history for this message
In , Dennis Schridde (devurandom) wrote :

The connection is gigabit LAN and the problem was [1] reproducible every time.
The server was provided by Xen running on a x86_64 RHEL 5.6.

[1] I did not try again since reporting the bug, but until then it was reproducible for several weeks.

Revision history for this message
In , Smithjd15 (smithjd15) wrote :

KRFB and KRDC seem to function fairly well as a pair after kde 4.8.0. I think the issue may have been in kwin.

Revision history for this message
In , Dennis Schridde (devurandom) wrote :

(In reply to comment #6)
> KRFB and KRDC seem to function fairly well as a pair after kde 4.8.0. I think
> the issue may have been in kwin.
The issue did not appear in conjunction with KRFB, but with the Xen VNC server. Does the KRFB/KRDC combination use VNC at all?

Revision history for this message
In , Smithjd15 (smithjd15) wrote :

On Saturday February 4 2012 12:36:10 PM Dennis Schridde wrote:
> https://bugs.kde.org/show_bug.cgi?id=274816
>
>
>
>
>
> --- Comment #7 from Dennis Schridde <devurandom gmx net> 2012-02-04
> 12:36:10 --- (In reply to comment #6)
>
> > KRFB and KRDC seem to function fairly well as a pair after kde 4.8.0. I
> > think the issue may have been in kwin.
>
> The issue did not appear in conjunction with KRFB, but with the Xen VNC
> server. Does the KRFB/KRDC combination use VNC at all?

I often confuse krdc / krfb but the server uses vnc and the client uses rdp
and vnc.

Revision history for this message
GaryParr (gary-garyparr) wrote :

I see the same behaviour in Kubuntu 12.04 after switching over from Ubuntu 11.04 in an attempt to get away from Unity. The only additional information I can provide is that my session appears to work fine until I launch IE on the remote machine. At this point, the only workable solution is to disconnect the session, re-connect and immediately close IE. After that, the session is fine again. There may be other applications that cause this behavior but I have not stumbled upon any yet.

Revision history for this message
Launchpad Janitor (janitor) wrote :

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

Changed in kdenetwork (Ubuntu):
status: New → Confirmed
Revision history for this message
GaryParr (gary-garyparr) wrote :

Wanted to say I screwed up and miss-read the topic. I'm not connecting using VNC. I'm connecting to an XP instance using RDP. That said however, the symptoms are exactly the same as described in the original bug report. This may mean we are dealing with two different issues, however identical symptoms indicate they are the same underlying problem bubbling up into two different protocols. I am able to use Remmina for an RDP connection without experiencing this bug, so the problem seems isolated to krdc.

Revision history for this message
In , Uwolfer (uwolfer) wrote :

Can you still reproduce this issue with xen vnc and a recent version of KRDC?

Revision history for this message
In , Dennis Schridde (devurandom) wrote :

(In reply to comment #9)
> Can you still reproduce this issue with xen vnc and a recent version of KRDC?
I did not try in a long time. We use Vinagre now.

Revision history for this message
In , Andrew-crouthamel (andrew-crouthamel) wrote :

Dear Bug Submitter,

This bug has been stagnant for a long time. Could you help us out and re-test if the bug is valid in the latest version? I am setting the status to NEEDSINFO pending your response, please change the Status back to REPORTED when you respond.

Thank you for helping us make KDE software even better for everyone!

Changed in kdenetwork:
status: New → Incomplete
Revision history for this message
In , Andrew-crouthamel (andrew-crouthamel) wrote :

Dear Bug Submitter,

This is a reminder that this bug has been stagnant for a long time. Could you help us out and re-test if the bug is valid in the latest version? This bug will be moved back to REPORTED Status for manual review later, which may take a while. If you are able to, please lend us a hand.

Thank you for helping us make KDE software even better for everyone!

Changed in kdenetwork:
status: Incomplete → New
Revision history for this message
In , Justin Zobel (justin-zobel) wrote :

Thank you for reporting this issue in KDE software. As it has been a while since this issue was reported, can we please ask you to see if you can reproduce the issue with a recent software version?

If you can reproduce the issue, please change the status to "REPORTED" when replying. Thank you!

Changed in kdenetwork:
status: New → Incomplete
Revision history for this message
In , Bug-janitor (bug-janitor) wrote :

Dear Bug Submitter,

This bug has been in NEEDSINFO status with no change for at least
15 days. Please provide the requested information as soon as
possible and set the bug status as REPORTED. Due to regular bug
tracker maintenance, if the bug is still in NEEDSINFO status with
no change in 30 days the bug will be closed as RESOLVED > WORKSFORME
due to lack of needed information.

For more information about our bug triaging procedures please read the
wiki located here:
https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging

If you have already provided the requested information, please
mark the bug as REPORTED so that the KDE team knows that the bug is
ready to be confirmed.

Thank you for helping us make KDE software even better for everyone!

Revision history for this message
In , Bug-janitor (bug-janitor) wrote :

This bug has been in NEEDSINFO status with no change for at least
30 days. The bug is now closed as RESOLVED > WORKSFORME
due to lack of needed information.

For more information about our bug triaging procedures please read the
wiki located here:
https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging

Thank you for helping us make KDE software even better for everyone!

Changed in kdenetwork:
status: Incomplete → Invalid
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