Conventions and Tools » History » Version 47
Leon Mualem, 05/27/2019 07:48 PM
updated server configs and deleted obsolete configs for detectors that no longer exist.
h1. Conventions and Tools
The user interface environment to the DAQ system is hosted in VNC servers running on DAQ cluster computers at various sites. Users interact with these via VNC viewers hosted on control room desktops, and for experts, on their own desktop or laptop.
The NovaControlRoom package contains icons and scripts to automatically set up the needed ssh tunnels, and launch the VNC viewers.
h3. VNC Viewers
The command to start a viewer is in the script launched by the desktop icons, but the underlying command is of the form
<pre> vncviewer -Fullscreen -Shared -passwd ~/.vnc/passwd :<NN> </pre>
<pre> -Fullscreen # starts in full screen mode
-Shared # keeps other users from getting disconnected from the server when you connect
NN # two-digit port number (relative to 5900) </pre>
h3. VNC Servers
In the current model (as of 2019-05-27), we employ 2 VNC servers for each detector, 2 expert desktops, and one for synoptic displays. In order to allow for different desktop environments on a single host machine, each VNC server on is run under a different account, using a dedicated port. We tend to use certain servers for particular functions, but this is subject to change.
The table below gives the machine, account, and port information for the stations used at a Remote Operation Center (ROC):
| *Station* |*Functions* | *Host* | *Account* | *Gateway* | *Remote Port* | *Gateway Port* | *Local Port* |
| 1 | FD Run Control
Message Logger | novadaq-far-master-02 | novacr01 | novadaq-far-gateway-01 | 5951 | variable | 5981 |
| 2 | FD Event Display
APD Cooling GUI | novadaq-far-master-02 | novacr02 | novadaq-far-gateway-01 | 5952 | variable | 5982 |
| 3 | Synoptics | nova-cr-03 | novacr03 | novadaq-near-gateway-01 | 5953 | variable | 5973 |
| 5 | ND Run Control
Message Logger| novadaq-near-master | novacr01 | novadaq-near-gateway-01 | 5951 | variable | 5991 |
| 6 | ND Event Display
APD Cooling GUI | novadaq-near-master | novacr02 | novadaq-near-gateway-01 | 5952 | variable | 5992 |
| -- | FD Expert Desktop | novadaq-far-master | novacr03 | novadaq-far-gateway-01 | 5953 | variable | 5983 |
| -- | ND Expert Desktop | novadaq-near-master | novacr03 | novadaq-near-gateway-01 | 5953 | variable | 5993 |
The *gateway* and *gateway port* are what you need to know to set up your own SSH tunnels so that you can view the sessions from your local machine. The gateway port can vary depending on the order the tunnels are set up. There are ROC scripts that determine the correct tunnel and can setup a new one if the tunnel does not exist. The *local port* is a recommendation for what port to use on your local machine.
The servers for each of these is set up to occupy a 1x2 monitor grid, with total pixel count 2560x2880.
h3. ssh Tunnels
ssh tunnels are required to access the port for a VNC server on a remote host (e.g., firstname.lastname@example.org for station 1 on NDOS) from a localhost (e.g., your laptop, or a control room desktop). Once launched, the tunnel can remain active indefinitely. The ssh command has the form
<pre>ssh -L <local_port>:localhost:<remote_port> -N -f -l <remote account> <remote host> </pre>
The ssh tunnel is authenticated using a kerberos ticket on the localhost, usually for a special use (i.e., non-personal) principle. That principle must be in the k5login file for the remote account, and the remote host must be directly reachable from the localhost (i.e., the localhost must be in the fnal.gov domain.)
On Windows, using RealVNC Viewer (renamed to vncviewer.exe), MIT Kerberos for Windows, and plink; the following batch file (FarDet1.bat) connects to the first screen of the Far Detector:
Start plink -ssh -L 5981:localhost:5981 <Principal>@<Gateway> "ssh -L 5981:localhost:5951 -N email@example.com"
start vncviewer -Shared -passwd passwd localhost:81
passwd is a file with the MD5'd VNC viewer password, and <Gateway> is a machine connected to the Fermilab network accessible from the outside. Using the tables above, it is possible to connect to any detector/station combination.