Changes between Version 10 and Version 11 of GENIEducation/SampleAssignments/OpenFlowLoadBalancerTutorial/ExerciseLayout/Execute


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Timestamp:
07/05/13 10:57:08 (6 years ago)
Author:
shuang@bbn.com
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  • GENIEducation/SampleAssignments/OpenFlowLoadBalancerTutorial/ExerciseLayout/Execute

    v10 v11  
    1818}}}
    1919
    20 = Debugging an OpenFlow Controller =
     20= 1. Debugging an OpenFlow Controller =
    2121You will find it helpful to know what is going on inside your OpenFlow controller and its associated switch when implementing these exercises. [[BR]]
    2222This section contains a few tips that may help you out if you are using the Open vSwitch implementation provided with this tutorial.
     
    3737 You will want to use a variety of Unix utilities, in addition to the tools listed in [http://groups.geni.net/geni/wiki/GENIEducation/SampleAssignments/OpenFlowAssignment/ExerciseLayout ExerciseLayout], to test your controllers. The standard ping and ''/usr/sbin/arping'' tools are useful for debugging connectivity (but make sure your controller passes ''ICMP ECHO REQUEST'' and ''REPLY'' packets and ''ARP'' traffic, respectively!), and the command ''netstat -an'' will show all active network connections on a Unix host; the TCP connections of interest in this exercise will be at the top of the listing. The format of netstat output is out of the scope of this tutorial, but information is available online and in the manual pages.
    3838
    39 = Implement a Load Balancing OpenFlow Controller =
    40  Files to download: [http://www.gpolab.bbn.com/experiment-support/OpenFlowExampleExperiment/load-balancer.rb load-balancer.rb] [[BR]]
    41  We will implement a Load Balancer OpenFlow Controller on node `Switch` using Trema. [[BR]]
    42  Load balancing in computer networking is the division of network traffic between two or more network devices or paths, typically for the purpose of achieving higher total throughput than either one path, ensuring a specific maximum latency or minimum bandwidth to some or all flows, or similar purposes. For this exercise, you will design a load-balancing OpenFlow controller capable of collecting flow status data from OpenFlow switches and using it to divide traffic between dissimilar network paths so as to achieve full bandwidth utilization. [[BR]]
    43  An interesting property of removing the controller from an OpenFlow device and placing it in an external system of arbitrary computing power and storage capability is that decision-making for network flows based on external state becomes reasonable. Traditional routing and switching devices make flow decisions based largely on local data (or perhaps data from adjacent network devices), but an OpenFlow controller can collect data from servers, network devices, or any other convenient source, and use this data to direct incoming flows. [[BR]]
    44  For the purpose of this exercise, data collection will be limited to the flow statistics reported by open vswitches.
     39= 2. Implement a Load Balancing OpenFlow Controller =
     40  - Files to download: [http://www.gpolab.bbn.com/experiment-support/OpenFlowExampleExperiment/load-balancer.rb load-balancer.rb] [[BR]]
     41  - We will implement a Load Balancer OpenFlow Controller on node `Switch` using Trema. [[BR]]
     42  - Load balancing in computer networking is the division of network traffic between two or more network devices or paths, typically for the purpose of achieving higher total throughput than either one path, ensuring a specific maximum latency or minimum bandwidth to some or all flows, or similar purposes. For this exercise, you will design a load-balancing OpenFlow controller capable of collecting flow status data from OpenFlow switches and using it to divide traffic between dissimilar network paths so as to achieve full bandwidth utilization. [[BR]]
     43  - An interesting property of removing the controller from an OpenFlow device and placing it in an external system of arbitrary computing power and storage capability is that decision-making for network flows based on external state becomes reasonable. Traditional routing and switching devices make flow decisions based largely on local data (or perhaps data from adjacent network devices), but an OpenFlow controller can collect data from servers, network devices, or any other convenient source, and use this data to direct incoming flows. [[BR]]
     44  - For the purpose of this tutorial, data collection will be limited to the flow statistics reported by open vswitches.
    4545
    46 == Experimental Setup ==
     46== 2.1 Experimental Setup ==
    4747  [[Image(OpenFlowLBExo.png, 30%, nolink)]] [[BR]]
    4848  Follow instructions in the [http://groups.geni.net/geni/wiki/GENIEducation/SampleAssignments/OpenFlowLoadBalancerTutorial/ExerciseLayout/DesignSetup DesignSetup] step to build a load balancing experiment topology. Your GENI resources will be configured in a manner similar to the above figure. The various parts of the diagram are as follows:
     
    5252    - '''Aggregator''': This node is a Linux host running Open vSwitch with a switch controller that will cause TCP connections to “follow” the decisions made by your OpenFlow controller on the Switch node. So leave this node alone, you only need to implement the OpenFlow controller on node `Switch`.
    5353
    54   '''Linux netem'''[[BR]]
     54== 2.2 Linux netem ==
    5555  Use the ''tc'' command to enable and configure delay and lossrate constraints on the outgoing interfaces for traffic traveling from the OpenFlow switch to the Aggregator node. To configure a path with a 20 ms delay and 10% lossrate on eth2, you would issue the command:
    5656{{{
     
    6060  The outgoing links on node `Switch` in the provided rspec are numbered 192.168.2.1 and 192.168.3.1 for left and right, respectively.
    6161
    62   '''Balancing the Load''' [[BR]]
     62== 2.3 Balancing the Load ==
    6363  An example openflow controller that arbitrarily assigns incoming TCP connections to alternating paths can be found at [http://www.gpolab.bbn.com/experiment-support/OpenFlowExampleExperiment/load-balancer.rb load-balancer.rb]. [[BR]]
    6464   Log on to node `switch`, download the load balancing controller by running:
     
    6868   (If you have already downloaded it, ignore this)
    6969 
    70    '''Run the experiment and monitor the load balancer''' [[BR]]
    71    Log on to your !LabWiki Account on http://emmy9.casa.umass.edu:3005 , on the `Prepare` Column, type `OpenFlow`, it will pop up with a list of .rb choices. Choose any one, and replace the whole content with the ruby script [http://www.gpolab.bbn.com/experiment-support/OpenFlowExampleExperiment/ExoGENI/loadbalancer_monitor.rb HERE]. [[BR]]
    72    
    73    Log on to node `switch` and do `ifconfig` to see the IP addresses on each interfaces. Identify the two interfaces that you want to monitor: the interfaces with IP address 192.168.2.1 and 192.168.3.1 respectively. On the !LabWiki page, in your ruby script, find the following line:
     70== 2.4 Use GIMI Portal to run the experiment and monitor the load balancer ==
     71   - Log on to your !LabWiki Account on http://emmy9.casa.umass.edu:3005 , on the `Prepare` Column, type `OpenFlow`, it will pop up with a list of .rb choices. Choose any one, and replace the whole content with the ruby script [http://www.gpolab.bbn.com/experiment-support/OpenFlowExampleExperiment/ExoGENI/loadbalancer_monitor.rb HERE].
     72   - Log on to node `switch` and do `ifconfig` to see the IP addresses on each interfaces. Identify the two interfaces that you want to monitor: the interfaces with IP address 192.168.2.1 and 192.168.3.1 respectively. On the !LabWiki page, in your ruby script, find the following line:
    7473{{{
    7574options = { 'sample-interval' => 1, 'monitor_interface' => 'eth1 -i eth3' }
    7675}}}
    77    Change eth1 and eth3 to the corresponding two interfaces you found with IP address 192.168.2.1 and 192.168.3.1 and press the `save` icon on your !LabWiki page.
    78 
    79    Drag the file Icon on your !LabWiki page from `Prepare` column and drop it to `Execute` column. Fill in the name of your !LabWiki experiment (this can be anything), the name of your slice (this has to be your slice name), and type `true` in the graph box to enable graph. And then press `Start Experiment` button.
    80 
     76   - Change eth1 and eth3 to the corresponding two interfaces you found with IP address 192.168.2.1 and 192.168.3.1 and press the `save` icon on your !LabWiki page.
     77   - Drag the file Icon on your !LabWiki page from `Prepare` column and drop it to `Execute` column. Fill in the name of your !LabWiki experiment (this can be anything), the name of your slice (this has to be your slice name), and type `true` in the graph box to enable graph. And then press `Start Experiment` button.
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