Changes between Initial Version and Version 1 of Tutorial/HowToAppPrototype


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Timestamp:
Nov 30, 2007, 5:37:32 AM (17 years ago)
Author:
thierry
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  • Tutorial/HowToAppPrototype

    v1 v1  
     1Go back --> [wiki:Tutorial Tutorials]
     2[[TOC(heading=Tutorial TOC, Tutorial, depth=2)]]
     3
     4= How to use execute an Application via a Prototype =
     5
     6=== Prerequisite ===
     7
     8This feature is only available in NodeHandler v4 and above.
     9
     10Before going through this tutorial, you should know the basics of writing and running an experiment script (see [wiki:Tutorial/HelloWorld here] and [wiki:Tutorial/HowtoWriteScripts here]).
     11
     12You should also have installed a disk image with Node Agent v4 on the nodes of the testbed you are using (e.g. "baseline.ndz"). See [wiki:Tutorial/HowToImage "How to install a disk image"].
     13
     14=== Goal ===
     15
     16In this tutorial, you will learn a method to execute an application using a prototype. This method is complementary to the two previous methods presented [wiki:Tutorial/HowToCommand here] and [wiki:Tutorial/HowToApplication here]. It is the recommended method if you have an application, which you would like to use in the long term with different (possibly dynamic) parameters.
     17
     18For example, this would be the case of a traffic generator that can generate multiple type of traffic depending on the parameters given by the experiment script. Using a prototype to execute this generator within your experiment allows you to:
     19 * run the application with different initial parameters without having to re-write any modified "wrapper" code,
     20 * change any eventual dynamic parameters during the application execution (e.g. change the rate of the generated traffic after 60sec)
     21
     22This method involves three steps:
     23 * the definition of a "wrapper" around your original application. This step would correspond to the creation of a generic Node Handler-compatible version of your application.
     24 * the definition of a so-called prototype. This step would correspond to the creation of a specific type or instance of your application.
     25 * the definition of an experiment script, which would use your application via its prototype.
     26
     27In the context of the above traffic generator example:
     28 * first step: you create an Node Handler-compatible application definition, which is a "wrapper" around your original application. This application definition will provide an interface to all the available parameters of your original application.
     29 * second step: you specialize the previous application definition in a prototype definition. For example you decide to define an instance of your application (i.e. a prototype) which will only generate a given traffic model (e.g. pareto) but which still accepts different parameter (e.g. packet size, rate, etc...). You may also decide to define a second prototype, which will generate another type of traffic.
     30 * third step: you define an experiment which will use this specialized application.
     31
     32The remainder of this tutorial describes these three steps and the execution of the related experiment script
     33 
     34=== Step 1: Application Definition ===
     35
     36=== Step 2: Prototype Definition ===
     37
     38=== Step 3: The Experiment Script ===
     39
     40This experiment is given in the attached script [attachment:a a].
     41
     42This file contains extensive comments that should help you understand the different steps involved in running an application on the nodes of a testbed.
     43
     44To run this example script, use the following command:
     45
     46 {{{
     47  orbit exec tut_app_1
     48 }}}
     49
     50=== The Results ===
     51
     52The experiment screen output should then look like [attachment:a this]. And the experiment log file should look like  [attachment:a this].
     53
     54=== More... ===