Multiple Workstations

Tim Wood timwood0 "at" pacbell.net
Thu Jan 15 18:26:01 2004


At 03:49 AM 01/15/04, Neild,Bruce wrote:
>I should clarify a few items.
>
>1) The GUI on the client workstation needs to be available only to that
>workstation.

How can you remote it then?  Assuming it's implemented right (probably safe given history), VNC's security should satisfy policy: password protected display, limitable to a single connection.  Run it over SSH and you have man-in-the-middle and eavesdrop protection.

>2) Once I have launched the application that uses the GUI I could
>disconnect as long as the application keeps running.  There is nothing I
>want or need to see on the desktop.  

Check.  Set up a minimal VNC desktop with your app. on it.  In X, you don't even need a window mgr.

>3) This process needs to be repeatable.  If the application ends and
>closes I need to be able to reset the workstation state to begin the
>process over with a clean start.  

Just connect to the VNC desktop again and restart the app.  Ending the X or Windows session gets you a new (VNC) desktop (and physical one on Windows.)

>4) The application is a purchased product.  I know it can be launched
>from the command line when you are logged on at a workstation.  I need
>to do this from a remote machine and with multiple instances.

Doable as described in my last msg.  With cmdline startup, you might be able to wrap the app. in srvany.exe on the Windows slave box and make it a system service that can start at boot (along with the VNC server).  Then you can log in remotely over VNC and check on the app. (the "interact with desktop" service option needs to be supported.)  Be careful of how many instances are running or can run, for licensing issues.

TW

-----Original Message-----
From: Tim Wood [mailto:timwood0 "at" pacbell.net] 
Sent: Wednesday, January 14, 2004 6:00 PM
To: Neild,Bruce
Cc: vnc-list "at" realvnc.com
Subject: Re: Multiple Workstations

At 06:53 AM 01/14/04, you wrote:
>Hello Everyone:
>I have been researching a method to run a GUI application on multiple
>workstations in the same network.  The application can be launched from
>the command line directly or via a batch file on a single workstation.
>It needs the desktop to interact with other GUI components.
>I would like to use a scheduling program on a master workstation or
>server (W2K or XP) to launch this application on other multiple
>workstations not in use by any other user.

If you write your application in X (probably Unix/Linux hosted, unless
there's an X library for Windows), it'll be easy: have your "slave"
workstations run the application instances, with their $DISPLAYs pointed
at the master server's Xvnc instance.  Then connect to that Xvnc
instance with vncviewer from anywhere and see all the app. instances.  I
think there's an obstacle to aggregating all the displays if the
application is Win32, even with VNC server or Term. Server on Windows
slave boxes, because there's no facility to aggregate all those virtual
desktops from the slave machines onto one display (physical or virtual).
(A VVNC might do it. :)  However if you don't mind having one vncviewer
process for each slave desktop, then yes, a VNC desktop running as a
service (for automatic startup) on each slave box makes sense.

YMMV, FWIW, HTH, etc.
TW