Introduction to PowerGraph

5 min read

Introduction to PowerGraph

As computers evolve, people are trying new methods do analyse how good some machine is when compared to another one. The amount of energy that some machine is consuming, seems to be a nice measure, once we are willing to produce faster and cheaper. IPMI(Intelligent Platform Management Interface), on the other side, is a set of computer interface specifications for an autonomous computer subsystem that provides management and monitoring capabilities independently of the host system. One of the measures that IPMI allow us to do is:

dcmi power reading

This command shows the instant power consumption. With this tools, my team decided to create a software that gets informations about the consumption of a machine and exports it on a readable way. Thats how we did it:

Infrastructure

The infrastructure was not so complicated to configure. We have to download some packages and set some configurations (process we are automating with Ansible). All the system is deployed on Minicloud. The packages (all via apt) we are using are:

  • ipmitool
  • apache2
  • python2.7
  • python-pip
  • git
  • htop
  • tmux

Besides, we are using crontab to be sure our service is still runing, and if it is not, restart it. We are doing this verification every ten minutes with the killer.sh script. To solve all Python dependencies you can run:

pip install -r requirements.txt

Apache configurations

Here you will install two modules in your apache server and change the virtual host configuration file. Doing this you will be able to control your browser’s cache.

In your server terminal run:

sudo a2enmod headers
sudo a2enmod expires
sudo service apache2 restart

After that, find your virtual host configuration file (/etc/apache2/sites-available/default/000-default.conf if you are using ubuntu OS) and insert the following lines, adjusting the parameters according to your needs:

<Directory /var/www/html>
   ExpiresActive On
   ExpiresDefault "access plus 10 minutes"
   ExpiresByType text/html "access plus 1 day"
   ExpiresByType text/javascript "access plus 1 day"

   # if it is your interest, you can set a specific expiration time for your csv file
   # ExpiresByType text/csv "access plus 30 seconds"

   <FilesMatch "file.csv">
         Header set Cache-control "no-cache"
   </FilesMatch>
</Directory>

Back-end code

PowerGraph was totally developed using Python. There are three main codes:

  • powergraph.py
  • graph_csv.py
  • csvcreator.py

Below, I will explain each code and its function.

powergraph.py

This is the code that keeps getting power info about a machine and save it to tinyDB or prompt the result to user. You can run it using the command:

python2.7 powergraph.py --host="server address" --port="server port" 
--user="allowed user" --passwd="password for this user"

You can use the optional parameter --store in order to save the infos as json on tinydb. Without this parameter, the script will print on the terminal. Besides, you can use --feedback with store in order to see the measures status. If you want to set the time interval that a new csv file is generated, you can use the flag --csv_interval. The --tail_length is used to set the number of lines the csv file will have.

csvcreator.py

This is the code that converts the JSON stored on tinyDB for a csv file. This code is really important, cause our front end is expecting a csv with two columns: timestamp and consumption. In order to run this code, you have to store the data of powergraph.py on the database, as we explained before. To run this use:

python2.7 csvcreator.py --jsonfile="generated_json_name"

There are two optional arguments: --date, to create the csv only with the data from a specific day and --name, with the name you want your csv file.

graph_csv.py

This is the code that orchestrates the other ones. It is a multithread code that creates one thread always running with the powergraph.py code and another one generating a new thread with csvcreator running from time to time updating the measures. To run this code use:

python2.7 graph_csv.py --host="server address" --port="server port" 
--user="allowed user" --passwd="password for this user" 
--jsonfile="path to bd jsonfile"

Besides, you can use the following optional arguments:

  • interval: interval between each ipmi measure (default=10)
  • nread: number of ipmi measures to be done (default=infinity)
  • csv_interval: interval that a new csv file is made (deafult=300s)
  • tail_length: size of the csv files (default=300)

Front-end code

In order to create an interactive website that plot a graph from the csv file, you first need to deal with the following dependencies:

  • apache configurations
  • javascript libraries

After that, we have developed the code in javascript/graph.js where you can read and present in real time the data provided by the back-end.

Javascript libraries

Here we have three libraries included in our html file (index.html).

The first one is the D3.js library, a worldwide known tool to create dynamic and interactive data visualizations, in other words, this is the engine of the website. Insert in your html body the <script src="http://d3js.org/d3.v4.min.js"></script> to get the most recent code from D3.js.

The next library, Moment.js, is used to manipulate date objects and in our case, for example, it allows us to show the time adjusted to the user’s location. You can download the code from the following address https://momentjs.com/downloads/moment.min.js.

Finally, the D3-tip library just inserts tooltips in the graph for a better experience of use. This library was donwloaded from https://github.com/Caged/d3-tip/blob/master/index.js. It is also interesting that you take a look our style implementation for the tooltips from the file style/style.css.

Conclusion

If you want to see the project working, acces this link. If you want to contribute, acces the github link. Hope you all enjoy it. Thanks a lot!