Bug 293587 - kdevelop over ssh X11 forwarding is very slow
Summary: kdevelop over ssh X11 forwarding is very slow
Status: RESOLVED FIXED
Alias: None
Product: kdevelop
Classification: Applications
Component: general (show other bugs)
Version: 4.2.2
Platform: Fedora RPMs Linux
: NOR normal
Target Milestone: 4.2.3
Assignee: kdevelop-bugs-null
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2012-02-07 23:59 UTC by Christopher Heiny
Modified: 2013-12-21 12:01 UTC (History)
2 users (show)

See Also:
Latest Commit:
Version Fixed In:


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Description Christopher Heiny 2012-02-07 23:59:22 UTC
Version:           4.2.2 (using KDE 4.6.2) 
OS:                Linux

We're in the progress of updating our build/development machines from Fedora 14 to Fedora 16 (all 64-bit).  We're stuck on an issue, though - kdevelop running on an F16 machine and displaying on an F14 machine via ssh X11 forwarding is so slow as to be unusable.  For example: click on the scroll bar, and scrolling happens several seconds later.  Text display lags many characters behind typing.

Reproducible: Always

Steps to Reproduce:
Ssh -X from a F14 machine to an F16 machine.
start kdevelop
experience pain

Actual Results:  
Slowness as described in the details.

Expected Results:  
Kdevelop is the fast and easy to use IDE it was under F14 in these circumstances.

I'm not sure what information you might need to investigate this.  Let me what you need, and I'll try to provide it.

Marked this as "crash", because it basically renders kdevelop unusable.
Comment 1 Milian Wolff 2012-02-08 11:06:06 UTC
Not a crash, hence not marking it as such.

Have you tried the following:

- use a different Qt/KDE style (systemsettings -> application appearance -> style)
- use a different graphics system (kdevelop --graphicssystem raster)

generally, have you tried other applications such as kate or similar over ssh - do they work better?
Comment 2 Christopher Heiny 2012-02-08 16:10:43 UTC
OK, normal I can live with, but fixed? :-)

I'll try the style and graphics changes later this morning and let you know the results.
Comment 3 Milian Wolff 2012-02-08 16:51:31 UTC
jup, should be WAITINGFORINFO - sorry
Comment 4 Christopher Heiny 2012-02-08 21:09:46 UTC
Here's what I see in the apps I use day-to-day, without changing any settings:

konsole - seems happy.

konqueror - somewhat variable.  This Bugzilla page is working fine, but another page displaying some very simple HTML and a basic SVG graphic is noticably slow (a couple of seconds to render) vs Firefox over the same connection (almost instant).

kompare - works fine

kmail2 - OK, that has a whole bucketload of problems, but display sluggishness isn't one of them.

kate - same issues as kdevelop

kwrite - similar problems, but not as severe.

kdiff3 - scrolling is slow.  Also a click in the scroll bar is interpreted as two clicks (that is, a two screenful jump results, instead of one)
Comment 5 Milian Wolff 2012-02-09 13:43:28 UTC
right, so this is rather a kate "bug" or limitation. have you tried different styles, graphicssystems?
Comment 6 Christopher Heiny 2012-02-09 16:31:02 UTC
Haven't had a chance to try different styles/etc yet - I'll give that a shot today sometime.
Comment 7 Christopher Heiny 2012-02-09 20:44:58 UTC
There is no change in behavior with kdevelop --graphicssystem raster.

I'll try changing other setting later today.
Comment 8 Milian Wolff 2012-02-10 11:10:30 UTC
also try --graphicssystem native just to make sure.
Comment 9 Milian Wolff 2012-02-10 11:49:40 UTC
how fast is the connection between those machines btw? I heard that KDevelop is supposed to run just fine over a 100MBit connection.
Comment 10 Christopher Heiny 2012-02-10 16:44:00 UTC
I'll try --graphicssystem native later this morning.

Didn't get a chance to try the system settings changes (we're up to our armpits in alligators at the moment).

Both machines are plugged into the same 1Gb ethernet switch.  I'll try switching ports and switches, just in case there's an issue with the switch.
Comment 11 Christopher Heiny 2012-02-15 20:41:34 UTC
--graphicssystem native eliminates the issue.  Unfortunately, that switch isn't passed to sessions launched from the Sessions menu, so their behavior is still awful.  But it definitely makes it possible to use kdevelop across the network again.

Switching network cables and ports around doesn't seem to have made a difference.  I have yet to try a different switch.

For changing the QT/KDE style, should that be done on the remote machine or the local machine?
Comment 12 Milian Wolff 2012-02-16 14:01:54 UTC
This is odd, I'd presumed native would be the default. Have you changed this manually maybe? see e.g.: http://kde-apps.org/content/show.php?content=129817

and you are using kdevelop 4.2 right? I think in older versions we hardcoded the graphicssystem to raster, but not anymore.

anyhow, marking as resolved. please open a new bug report for the issue that the --graphicssystem cli argument is not passed to new sessions.
Comment 13 michel 2013-02-01 10:20:55 UTC
@Milian

Apparently it's not the default. We are on 4.8.2 and experience the same issue. Your fix solved it. Thank you very much! :)
Comment 14 Philipp A. 2013-12-21 12:01:53 UTC
this issue just came up on the mailing list, so since there’s interest in the explanation on why raster is the default graphics system: it’s independent of X11 and likely faster on local screens.

and X11 forwarding is slow in itself, anyways, so i rather use a RDP client like KRDC to get a compressed connection.