Beginning an Experiment

After logging on to the Emulab Web Interface, choose the "Begin Experiment" option from the menu. First select which project you want the experiment to be configured in. Most people will be a member of just one project, and will not have a choice. If you are a member of multiple projects, be sure to select the correct project from the menu.

Next fill in the `Name' and `Description fields. The Name should be a single word (no spaces) identifier, while the Description is a multi word description of your experiment. In the "Your NS file" field, place the local path of a NS file which you have created to describe your network topology. This file will be uploaded through your browser when you choose "Submit."

In submitting a topology, you can ask for as many nodes as are currently available. You can click on the "Node Reservation Status" link at your left to see how many nodes are currently free. If you ask for more than are currently available, your experiment will be rejected (you will receive email notification shortly after you submit your NS file to the web interface).

We urge all new Emulab users to begin with a small 3-4 node experiment so that you will become familiar with NS syntax and the practical aspects of Emulab operation.

After submission, Emulab will begin processing your request. This will likely take several minutes, depending on how large your topology is, and what other features (such as delay nodes and bandwidth limits) you are using. Assuming all goes well, you will receive an email message indicating success or failure, and if successful, a listing of the nodes and IP address that were allocated to your experiment.

Problem?

If your submission fails because there are not enough nodes available, do not repeatedly re-submit the experiment every few minutes. It wastes your time and floods us with email (we get every failure message you do!) Instead, you can now use the Batch System to queue an interactive job. By submitting your experiment as a batch job, but without any tb-set-node-startcmd directives in your NS file, the job will be queued until nodes are available. For most experiments, this means just using your regular NS file, and checking the Batch Mode Experiment box when you create the experiment. Note: if your experiment requires a large proportion of the total Emulab nodes, you likely require Testbed Operations intervention to get your experiment off the ground.

When your queued job is swapped in, you will be sent email to inform you, and you can start working! Please note that the experiment will be idle when it is swapped in, and will be idle swapped if you do not get things running on the nodes in a short period of time. If your experiment does get swapped out before you can get to it, you can always visit the experiment's information page and try again by using the Queue Batch Experiment menu item.