dbus and kde on terminalserver

[Joerg Barfurth]

Hi,

Wilhelm Meier wrote:

> If we assume a client-machine running as thin-client (the thin-client has no 
> local apps nor the user logs into this client) and a terminalserver the user 
> logs in, logically the hardware of the thin-client belongs to the session, 
> the user opens on the terminalserver. 

Depending on the thin-client/terminal-server architecture this may not 
be entirely true as well. Sun Ray supports 'session mobility': you can 
detach a thin-client from a running session and reattach to the same 
user session from a different thin-client.

So the thin-client hardware belongs to the terminal-session on the 
server, which is distinct from the user login session.

> If the user plugs-in a device, the local hald on the thin-client sends 
> messages to the dbus of the thin-client, which are not recognized (there is 
> no session). Now, one could make the new device of the thin-client available 
> on the terminalserver, for instance via network-block-device. In this case it 
> would be useful to inform the session on the terminalserver of the new device 
> for the session. 
> 

Again this is even more pointedly so in the Sun Ray case: the 
thin-client doesn't run a local hald (or in fact any general purpose 
OS). If a usb device (other than mouse/keyboard) is plugged into the 
thin-client a new device is made available on the terminal server. But 
it isn't entirely clear how to do HAL-style notification for this.

> The LTSP-people do something similar, but without using hal/dbus I think. 
> 

Well, some of the assumptions inherent in a global system bus break down 
in a thin-client scenario, and I believe that in general the session bus 
is an incomplete replacement for it. Session mobility or user switching 
on the thin client a scenarios that expose the need for another scope 
for signal distribution.

- Joerg

-- 
Joerg Barfurth              Sun Microsystems - Desktop - Hamburg
 >>>>>>>>>>>>>>>>>> using std::disclaimer <<<<<<<<<<<<<<<<<<<<<<<
Software Engineer                         joerg.barfurth at sun.com
Thin Client Software