X11 Remote Applications Responsiveness

Tue, 30 Dec 2008 15:01:43 +0000

As a developer, I use eclipse a lot… We have a powerful server that off which eclipse is run which allows us to keep the desktops at a much lower spec. In general, this works well for us.

However, recently, I have been niggled by the amount of time it takes to switch perspectives on eclipse. It takes a good 4 seconds to switch between perspectives.There is also a noticeable lag when performing some operations.

To resolve this, I spent a lot of time looking at the linux real-time and low-latency patches. I had expected that running X11 applications remotely would not cause a bottleneck over a gigabit link. Turns out that I was wrong.

To test this, I ran a vnc server on the application server and found that switching perspectives on there was super fast.

To be able to resolve this, the first thing to do was to remove any latency put on the X->X communication by ssh.

We use gdm, so I had to enable to TCP on there first. Do this using the following config line in /etc/gdm/gdm.conf

``` DisallowTCP=false ```

Restart gdm

on the remote host, export DISPLAY

``` export DISPLAY=:0 ```

and run your application.

I found the application to be a lot more responsive after this. I didn’t have to worry about X auth since we have nfs mounted home. If you don’t, check this mini howto

Ssh on despatches

X11 Remote Applications Responsiveness