wiki:GENIEducation/SampleAssignments/UnderstandAMAPI/Procedure/Execute

Version 17 (modified by sedwards@bbn.com, 6 years ago) (diff)

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Understanding the AM API

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4 Wait for experiment setup

You can tell whether your nodes are ready by using a script built on omni called readyToLogin.

  1. Please use the command:
    readyToLogin --no-keys -a AM_NICKNAME SLICENAME
    
    where (as before) AM_NICKNAME and SLICENAME are your aggregate
    manager nickname and your slice name (both found on your worksheet).
      
  2. If it reports that the sliver is not yet ready (for example, it might say that the status is "changing"), then please wait a minute or two and try again. Once everything is complete, readyToLogin will give output that should look something like this:
    ...
    server's geni_status is: ready (am_status:ready) 
    User example logs in to server using:
    	ssh -p 32768 example@pc1.utah.geniracks.net
    User example logs in to client using:
    	ssh -p 32769 example@pc1.utah.geniracks.net
    ...
    
    If you didn't previously complete the Flack tutorial (or are not running an ssh agent), then your ssh client might not be set up to log in with above commands. Try re-running readyToLogin without the --no-keys option, and it will give you one or more ssh commands to choose from (which should work, although might require the key passphrase).

5 Browse server webpage and log in to client node

The install and execute services requested in our RSpec have already started, and the apache webserver has started on the server and measurements are now being collected.

  1. Enter the hostname of the server node in your browser. It should bring up a webpage of statistics from your experiment similar to that shown in the figure.
  2. Copy and paste the ssh command lines for your client directly into your terminal to log in. You should see a shell prompt from the remote end:
         [example@client ~]$
    
    Note While you're welcome to inspect either the client or server, for the purpose of this experiment the client host is the one running the iperf tests and collecting all the logs.
  3. Inspect the /local directory:
    cd /local
    ls
    
    Look for the iperf and wget processes:
    ps ax
    
    Tip If you do not see the proper files and processes, please double-check the RSpec you used in the previous step.
Enter the hostname in your browser to see statistics

Figure 5-1 Enter the hostname of the server node in your browser to see statistics

The client machine is saving all the test results in the /tmp/iperf-logs directory. Files with timestamps in the names will gradually appear there (there are 100 tests overall, and it may take 20 minutes for all of them to complete if you want to wait for them).

Each log file corresponds to one test with some number of simultaneous TCP connections over the VLAN link you requested between the two hosts. Later tests gradually include more concurrent connections, so the throughput of each individual connection will decrease, but the aggregate throughput (the [SUM] line at the end of each file) should remain approximately consistent.

6. Analyze Experiment

For a real experiment, of course, this step would be the most important and collection, analysis and archival of the results would be critical, but for now, play around as necessary to satisfy your curiosity and then continue.


Introduction

Next: Finish