Download Thesis Title

5.4
Experiments
In order to evaluate the usability, the server was deployed and the definition and execution of jobs
where assessed. Three experiments with different input files, outputs and arguments where made.
For each experiment, we created a torrent containing the input file names and possible executables or
scripts. The first experiment performed consisted of a simple Python script reading one file, converting
all characters to uppercase and writing them to an output file. In the following paragraphs we will explain
each step taken. The first preparation step consisted in copying the python script and input files to one
directory, for this experiment it will be called test1. The names of the various input files does not matter.
Next, the nuBOINC manager was used to generate the torrent file by selecting all files in the test1
directory. As soon as it was generated the contained folder was opened, so as to display the location of
the torrent file.
When creating jobs, the website will first require the generated torrent file. After uploading it the
website will display the torrent files and provide options to select one file as executable, and to include
files in each task. For test1 the python script was selected as executable and python was selected as
the executable’s caller. After filling out the rest and triggering the create button the website will send
queries to the server in order to create a job for each input file.
In order to test multiple input and output files, the previous application was adapted so that it applies
the same process to two input files and writes the result to two output files. Furthermore, it was run
with the Python interpreter PyPy, which demonstrates that the defined package PyPy was installed. In
the last experiment, a video should be processed with avconc to add an effect. First, the video was
split into 5 parts using avconv. Afterwards, it was possible to apply the same steps as done before. On
the website, we defined two packages that are required by avconv (libav-tools and libavcodex-extra-53),
note that this package combinations is valid for Ubuntu 13.10, but not for Ubuntu 14.04. Consequently,
it is important to verify the package combination on the target Ubuntu version. All tasks were executed
successfully and all results were transmitted back to the nuBOINC Manager.
5.4.1
Credits
We performed 3 experiments to test the slightly modified credit system. In order to perform the
experiment we registered 3 users: User1, User2 and User3.
5.4.1.A
Experiment One: Granting Credit
The objective of this experiment is to verify that jobs created by one user and executed by the same
are not granted credit. For the purpose of this experiment the accounts User1 and User2 are used. Both
submit jobs, but only User1 will process jobs. First we only submitted jobs using User1.
The submitted jobs are the same previously used to process video segments with avconv. The data
in the following tables have been obtained from the BOINC database. Before executing the jobs, each
user had 0 credits, afterwards they are still 0, because User1 processed his own jobs. Note that the
51