Version 44 (modified by, 5 years ago) (diff)

Systematic Experimentation version

Understanding the AM API using Content Centric Networking

Image Map

1. Design the Experiment

  1. In today's experiment you will use resources at the aggregate listed on the worksheet. If you don't have a worksheet use Clemson InstaGENI (aka

2. Establish the Environment

2.1 Pre-work: Ensure SSH keys are setup

Verify that you have at least one public key associated with your account. To do that, after you login to the portal check under your Profile, under the SSH keys tab. If you do not have SSH keys associated yet, please follow the instructions on that tab of the Portal.

2.2 Configure Omni

  1. Login to the GENI Portal
  2. Click on the `Profile tab` link on the top of your screen. Then click on the `Configure omni` tab under `PROFILE`.

Figure 2-1 Click on the Configure omni tab under Profile.
  1. Click on the `Download your omni data` button under step 2.

Figure 2-2 Download your omni data under step 2.
  1. If this is the first time you try to access your GENI certificate you will have to generate one. Click on the `generate a certificate` link.

Figure 2-3 Click on Generate a certificate.
  1. Unless you really understand how SSL certificates work, choose the simple option. Click on the `Generate Combined Certificate and Key File` button and then click on `Close`. You will be taken back to the download page with the warning. Reload the page to enable the download button.

Figure 2-4 Click on Generate Combined Certificate and Key File.
  1. If you are a member of more than one project, select which project you would like to be the default one for running experiments in GENI. You can always change the project that is used by the `-r` command line option of Omni. Then click on `Download your omni data`.

Figure 2-5 Click on Download your omni data.
  1. The bundle will be saved at ~/Downloads/omni.bundle
  2. Open a terminal window and type:
    The cert and key files you need will be installed in the appropriate folders.

3. Obtain Resources

3.1 Create a slice

Create a slice using omni and the slice name of your choice. From now on that slice name will be referred to as SLICENAME.

$ omni createslice SLICENAME

3.2. Load a simple topology in Jacks

For this exercise, we will edit an existing RSpec file. Start by loading this predefined topology into Jacks.

  1. In the Portal, open the Slice page for the slice you just created. Notice that you created the slice with omni and it is available via the Portal.
  2. Press the Add Resources button to launch Jacks for this slice.
  3. From the Choose RSpec menu (see figure), select the URL button.
Import an RSpec into Jacks
Figure 3-1 Import an RSpec into Jacks.
  1. Enter the URL for the RSpec:
    then click Select.
  2. After you click Select, a network topology should appear on the canvas.

3.3. Modify the RSpec to automatically install and execute CCNX software

For this experiment, we need to install the following software on the nodes:

  • The CCNX software (ccnx-0.6.2.tar.gz)
  • Scripts that set up the CCNX software (ccnx-setup.tar.gz)
  • Scripts used to pull atmospheric precipitation data using the CCNX protocol (ccnx-atmos.tar.gz)

When the nodes start up, we need the following scripts to be executed:

  • Script that sets up the node (node-setup)
  • Script that sets up the ccnx protocol (ccnx-setup)
  • Script that setup up ccnx protocol routes (add-precip-routes)

We automate the installation and running of the proper software using install and execute scripts in the RSpec. These can be added by selecting the Add button under the Install Scripts and Execute Scripts fields for each node.

Most of the nodes have an install script specified for each of the three pieces of software listed above which loads a tarball of software onto each node:


Likewise, the nodes have execute scripts to configure the software on each node:

  • cd /tmp/ccnx-setup && ./node-setup
  • cd /tmp/ccnx-setup && ./add-precip-routes rsrchr
  • cd /tmp/ccnx-setup && ./ccnx-setup router 4
You DO NOT have to specify install and execute scripts for the nodes as they have already been done for you. You can check this by clicking on the icons for these nodes.

In general, one should be very careful when entering this information -- these commands will not be executed yet, so it will be some time before you will see any relevant error messages if there is a mistake here.
  1. Click on each node to manipulate details of the node configuration.

    The ccnx-setup execute command takes as parameters the name of a single "barrier" node, which must be up in order for the experiment to start, and the number of nodes in the topology as follows:
    We will continue to use the node ccnx-router as the barrier node.

    We will add two nodes to the topology, so go ahead and change the number of nodes from 3 to 5. The new ccnx-router execute command on all three nodes should be:
    cd /tmp/ccnx-setup && ./ccnx-setup ccnx-router 5
    Note When you open the node information, you should see a new pane with fields to fill in like in the figure.

Figure 3-2 Edit all three nodes
  1. Copy the user node by:
    • Click on the user node.
    • Press the Duplicate Nodes Only button.
    • A node user-0 should appear. Look at the install and execute scripts. They should be the same as on the original user node.
  2. Copy the ccnx-router node the same way. The new node should be ccnx-router-1.

Figure 3-3 Copy the ccnx-router and user nodes.
  1. Draw a link between the ccnx-router and ccnx-router-1 nodes.
  2. Draw another link between the new ccnx-router-1 node and the user-0 node.
  3. The topology should look like Figure 3-4

Figure 3-4 Draw links to connect the nodes.
  1. Press the Auto-IP button to automatically assign IP addresses to each interface in the topology.
  2. The add-precip-routes execute command takes as a parameter the name of the "next hop" node, which is the next node on the path to the data node:
    add-precip-routes NEXT_HOP_NODE

    Edit the new ccnx-router-1 node to point to ccnx-router.

    The new add-precip-routes execute command on ccnx-router-1 should be:
    cd /tmp/ccnx-setup && ./add-precip-routes ccnx-router
  3. Edit the new user-0 node to point to ccnx-router-1.

    The new add-precip-routes execute command on user-0 should be:
    cd /tmp/ccnx-setup && ./add-precip-routes ccnx-router-1

Figure 3-5 Edit the next hop on ccnx-router-1 and user-0.

3.4. Export the modified request RSpec

Now we will pull back some of the covers and inspect exactly what Jacks has been doing for us when preparing the RSpecs for the experiments we design. Each node and link has a corresponding element in the RSpec, and the details of the component configuration (such as the install and execute services we requested above) are specified with attributes, or sometimes child elements, within those portions of the document.

  1. From the Add Resources window (see figure), select the View Rspec button on the top right hand side. This will bring up a pane showing the current RSpec -- please take a moment to inspect it. The `<node>` and `<link>` elements contain the specification for the components we will request, and if you look closely, you will be able to see the install and execute service elements you added earlier. Click on the "View RSpec" button again to return to the main screen.

Figure 3-4 View and save the final request RSpec
  1. Use the Download button (in the lower left part of the screen next to Save RSpec) to make a local copy of your RSpec with the name rspec.xml. We'll use this in the next step to demonstrate how other client tools also use RSpec files to communicate requests to aggregate managers.

3.5. Instantiate the new experiment using Omni

For this step, we'll change the approach a bit and switch to a new client tool, the command line Omni client.

From a terminal, please enter the command:


where AM_NICKNAME is the nickname for your assigned aggregate manager and SLICENAME is the name of the slice you created earlier (both of these are given on your worksheet). RSPEC_FILE should be replaced with the filename of the RSpec you saved in step 3.4.

If all is well, Omni should give you a number of informational messages, such as:

INFO:omni:Loading config file /home/geni/.gcf/omni_config

It should quickly proceed to the point where it makes the request to the remote manager:

INFO:omni:Creating sliver(s) from rspec file /home/geni/Downloads/experiments.rspec for slice ...

This step can sometimes be time-consuming, so please be patient. If it succeeds, within a couple of minutes Omni should report:

INFO:omni: Completed createsliver:

and your resource reservation is complete!


Next: Execute