Monday Exercise 1.1: Log In and Look Around

The goal of this first exercise is simply to log in to the local submit machine and look around a little bit.

This exercise should take only a few minutes. If you have trouble getting ssh access to the submit machine, ask the instructors right away! Gaining access is critical for all remaining exercises.

Logging In

Today, you will use the machine named learn.chtc.wisc.edu for all of your exercises.

To log in, use a Secure Shell (SSH) client.

%UCL_PROMPT_SHORT% <strong>ssh [email protected]</strong>

If you need help finding or using an SSH client, ask the instructors for help right away!

Once you have an SSH client, use it to log in to the submit machine. Some tips:

Running Commands

In the exercises, we will show commands that you are supposed to type or copy into the command line, like this:

%UCL_PROMPT_SHORT% <strong>hostname</strong>
learn.chtc.wisc.edu

Note: In the first line of the example above, the %UCL_PROMPT_SHORT% part is meant to show the Linux command-line prompt. You do not type this part! Further, your actual prompt probably is a bit different, and that is expected. So in the example above, the command that you type at your own prompt is just the eight characters hostname. The second line of the example, without the prompt, shows the output of the command; you do not type this part, either.

Here are a few other commands that you can try, to learn a little bit about this machine (the examples below do not show the output from each command):

%UCL_PROMPT_SHORT% <strong>date</strong>
%UCL_PROMPT_SHORT% <strong>uname -a</strong>

A suggestion for the day: Try typing into the command line as many of the commands as you can. Copy-and-paste is fine, of course, but you WILL learn more if you take the time to type each command, yourself.

Organizing Your Workspace

You will be doing many different exercises over the next few days, many of them on this submit machine. Each exercise may use many files, once finished. To avoid confusion, it may be useful to create a separate directory for each exercise.

For instance, for the rest of this exercise, you may wish to create and use a directory named monday-1.1-login, or something like that.

%UCL_PROMPT_SHORT% <strong>mkdir monday-1.1-login</strong>
%UCL_PROMPT_SHORT% <strong>cd monday-1.1-login</strong>

Showing the Version of HTCondor

HTCondor is installed on this machine. But what version? You can ask HTCondor itself:

%UCL_PROMPT_SHORT% <strong>condor_version</strong>
$CondorVersion: 8.7.2 Jun 02 2017 BuildID: 407060 $
$CondorPlatform: x86_64_RedHat6 $

As you can see from the output, we are using HTCondor 8.7.2, which is the most recently released development version.

Background information about HTCondor version numbers

HTCondor always has two types of releases at one time: stable and development. HTCondor 8.4.x and 8.6.x are considered stable releases, and you can know they are stable because the second digits (e.g., 4 or 6 in these cases) are even numbers. Within one stable series, all versions have the same features (for example 8.4.0 and 8.4.8 have the same set of features) and differ only in bug and security fixes.

HTCondor 8.7.2 is the current development release series of HTCondor. You know that it is a development release because the second digit (i.e., 7) is an odd number. Typically, the current development series (i.e., 8.7.x) has greater version numbers than the current stable series (i.e., 8.6.x), but that is not always true. In any case, development releases add new features and are more likely to have problems. For that reason, we typically do not use development releases for the School, but in this case, 8.7.2 is considered stable enough.

References

Here are a few links to reference materials that might be interesting now or later.