Using a Multi-User Computing Server Remotely

Using a Multi-User Computing Server Remotely
Michael A. Covington
Artificial Intelligence Center
The University of Georgia
Last revised 2005 September 29

Meet Darwin and Mendel...
Darwin (darwin.ai.uga.edu) and Mendel (mendel.ai.uga.edu) are PC that we have made available remotely so that you can run long computations without tying up the computer in your office.
They named Darwin and Mendel because we expect them to be used mainly for genetic algorithms.
You can connect to Darwin or Mendel by remote desktop, start a computation, disconnect, go away, come back hours or days later, and connect to the same session again to see the results. The program will have been running the whole time, even when you were disconnected.
Each machine has two Intel Xeon 3-GHz CPUs each with 2 instruction pipelines. Windows sees it as a 4-CPU machine and will automatically distribute the work among the CPUs.

Acceptable-use policies
Darwin and Mendel are for long computations that would otherwise tie up a regular computer, and for access to special software provided only on these machines. They are not intended as a substitute for the computer in your office.
Normal practice is to develop your programs on your own PC, then run them on Darwin or Mendel. There are some software development tools on Darwin and Mendel, but they are intended for quick corrections rather than major projects.
We assume you will make a good-faith effort to make your program efficient before letting it consume a lot of CPU time.
CAUTION: We cannot guarantee days and days of uninterrupted computation. Your program should save intermediate results every few hours.
Quick start
(0) If you are outside the AI Center, connect to the VPN.
(1) Go to Programs, Accessories, Communications, Remote Desktop Connection.
(2) Connect to darwin (or, from outside our lab, darwin.ai.uga.edu). (Or mendel, also known as mendel.ai.uga.edu.)
(3) Log onto Darwin or Mendel as a roaming user in the normal way.

Make sure you are logging into the AIUGA domain (circled).
(4) At the top of your screen will be a control bar like this:

If you like, you can put your remote session into a window, or alternate between it and your main session.
(5) Start your programs running.
(6) When you're finished:
-- If you want to leave programs running and log back on to see them later, click on the X on the control bar at the top of the screen.
-- If you want to end your session, log off in the usual way (Start, Log Off).
Communication between Darwin, Mendel, and your own PC
If you are a roaming user, you will be able to get to your files from Darwin and Mendel the same way as from a regular AI Center PC, without any special action.
Remote Desktop Connection allows you to share the clipboard between your PC and your remote session. You can copy and paste text and graphics (but not files) from one to the other.
If you wish, you can set options so that Darwin or Mendel can access your own PC's disk drives and printers. See next section.
Options when you connect
You can set a number of preferences when you connect, and save a customized shortcut to Darwin or Mendel on your desktop. Here's how.
(1) Programs, Accessories, Communications, Remote Desktop Connection:
← Click Help here to learn a LOT more!
(2) Click Options, then Local Resources and other tabs to set whatever you want:

Note that you can let Darwin use the disk drives and printers of your local PC. If you choose to do this, you'll find the local disk drives in My Computer on Darwin, with drive letters of their own.
(3) Under the General tab, choose "Save As..." to store the shortcut on your desktop, or anywhere you want:

(4) To connect to Darwin, simply double-click on the saved shortcut:

Using Task Manager
When you log in, you will see Task Manager running, with an indication of the CPU load:

Note that Task Manager will remember any tabs or settings that you click, and will come up next time the way you left it.
(We suggest unchecking "Always on top," under Options.)
Note also that you will not see all 4 pipelines and you cannot see users' names or processes other than your own. Thus, if you are not Administrator, Task Manager will always tell you, misleadingly, that you are the only user.
Tips for running long computations
(1) Make sure your program saves intermediate results every few hours. We cannot guarantee that Darwin will go forever without rebooting.
(2) If your program needs rapid disk access, have it read and write your desktop, or C:\TEMP, rather than your U: drive, because your desktop resides on Darwin or Mendel while you are logged in there, but your U: drive stays on the server at all times.
(3) If you are using Java or Prolog, and you need a lot of memory, make sure you set sufficiently high memory limits. By default, these languages will not use all the memory on the machine.
(4) You can only have one session, but you can run as many programs as you like, concurrently.
(5) There is no easy way to measure the amount of CPU time taken by your program, because you do not know, at any moment, what else you're sharing the machine with.