What does one want to see in a data center layout?
When one sees a geographical map of a city, one is interested in the streets, the buildings, the parks, commercial establishments, houses etc. Similarly when a data center operator sees a data center layout he/she is interested in the aisles: 1) Cold aisle – the cool air is blown to the racks from this aisle 2) Rack aisle – a row where racks are placed 3) hot aisle – aisle on the back side of rack where the hot air comes out. In addition to the aisles there are a number of other equipment that are seen in the data centers such as 1) Precision Air Conditioners (PACs) 2) Power Distribution Units ( PDUs) 3) Panels. By looking at a data center layout diagram one must know the current state of the layout – where each asset is, how much is utilized?
Hence broadly the requirements for data center layout are:
1) To depict the aisles – hot, cold and rack aisles
2) To show the equipment on the floor – PDUs, Panels,, PACs
3) To show walls separating adjacent rooms
4) To show entry/exit doors
5) To be able to add/move/delete assets such as Racks, PDUs, Panels, sensors.
Implementation methodology & technology choice
The model and visualization implementation choices are many. The obvious choice is to use Java technologies such as Javascript and JSP. However, it is ideal to separate the model from visualization. Let us take couple of examples to drive home the point. When we describe a circle it is sufficient to say where the center is and the size of the radius. Now how we draw the circle on the screen is a separate task. Similarly when we describe a room, if we specify its coordinates and which corner some furniture is placed we can form an idea of the room even before it is shown to us pictorially. It is universally accepted principle in computing that model (or data) is separated from the algorithm which deals with the data. If we have a text file which describes the data center and if the text file can be easily edited by hand or program, the code becomes much more flexible to extend and maintain. With that goal in mind we set out to choose the best implementation choice for data center layout. GFS accomplished this separation by using XML, XSLT technologies. We were also able to overlay the assets with real time monitored data for the assets.The solution is extensible, flexible and can be customized for a particular data center. Yes we did actually customize it for a diesel generator enclosure showing DG sets, buffer tanks, flow meters vindicating that XML, XSLT is the right choice for modelling and visualization of data center layout.