[Thinlinc-technical] dynamically choosing terminal server

[Peter Astrand]

Hi. I'd say that you should go for option 2, "At a lower level". With 
individual virtual machines, one would typically have the possibility of 
giving administrator/root access to the users. That's one of the 
advantages with individual virtual machines compared to multi user 
terminal server solutions. However, the ThinLinc cluster security model is 
based on the fact the all machines are controlled by the 
administrator/root. Thus, you should not add machines to a TL cluster 
which are controlled by end users. Also, even though the TL load balancer 
scales well, it's not designed for 1000 machines.

So, you should go for a solution with 2 or more terminal servers which 
hosts the base user sessions (Xserver). Then, there are multiple options 
for using and connecting to virtual machines:

* If you are using a hosted hypervisor such as VMware workstation or 
VirtualBox, you can run those directly on the ThinLinc servers, inside the 
user sessions.

* You can also define a profile (see profiles.hconf) that connects to a 
virtual machine and runs the desktop environment there. In principle, you 
should be able to define a profile which runs "tl-run-unixapp 
gnome-session" or similar.

Almost every aspect of the session startup can be customized. As a 
starting point, take a look at:

http://www.cendio.com/resources/docs/tag/configuration_customizing_user_session.html#configuration_session-startup-vsmagent

Br,
Peter




On Thu, 25 Sep 2014, Rob De Langhe wrote:

> 
> hy ThinLinc enthousiasts,
> 
> I am looking for a 'best practice' to box users in their individual virtual server.
> 
> At the highest level, I can choose to create individual terminal servers at the time where a new user gets defined in the system
> (that user list will probably be kept in LDAP). So this would become potentially many (10's, 100's or even 1000's) of terminal
> servers.
> - disadvantages (if I understood well) : not sure (documentation?) how we can replace the load-balancing method of the VSM server
> by some mechanism to force the VSM server to startup a session on a specific terminal server for an authenticated user ; a bit of
> effort to develop the automated creation/drop of virtual servers when users are created/deleted
> - advantages : user sessions are boxed ; virtual servers can be created and resources can be assigned/tuned dynamically
> 
> At a lower level, I can define 2 (or more?) terminal servers to startup all user sessions. Is there a way to replace the startup of
> a user session on the terminal server by a script which determines a virtual server to use for that user, starts that virtual
> server (1-2 seconds needed only) does a X11-forwarded SSH connection to that virtual server and starts there a GNOME2 (or whatever
> chosen) X11 session
> - disadvantages : not sure (documentation?) how we can replace the session-startups on terminal servers by some new self-developed
> script (which will figure out the virtual server to use for this new session, startup that virtual server, SSH to it and starts
> session on it)
> - advantages : any server and any UNIX flavor can act as guest host to run such virtual servers ; virtual servers are totally
> independent from ThinLinc ; more control over the actions performed by the script running on the ThinLinc terminal servers
> 
> Any comments, experiences, hints ?
> 
> best regards,
> Rob
> 
> 
>


---
Peter Astrand		ThinLinc Chief Developer
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