The aim of this simulator is allow quick testing of new brownout replica controller. More information about brownout can be found in the following article:

Cristian Klein, Martina Maggio, Karl-Erik Årzén, Francisco Hernández-Rodriguez, "Brownout: Building More Robust Cloud Applications", ICSE, 2014

A pre-print can be downloaded here.

Self-adaptation is a first class concern for cloud applications, which should be able to withstand diverse runtime changes. Variations are simultaneously happening both at the cloud infrastructure level - for example hardware failures - and at the user workload level - flash crowds. However, robustly withstanding extreme variability, requires costly hardware over-provisioning.

In this paper, we introduce a self-adaptation programming paradigm called brownout. Using this paradigm, applications can be designed to robustly withstand unpredictable runtime variations, without over-provisioning. The paradigm is based on optional code that can be dynamically deactivated through decisions based on control theory.

We modified two popular web application prototypes - RUBiS and RUBBoS - with less than 170 lines of code, to make them brownout-compliant. Experiments show that brownout self-adaptation dramatically improves the ability to withstand flash-crowds and hardware failures.

To conduct the experiments, we used Ubuntu 12.04.2 LTS. Other software has been installed from the official repositories, specifically:

• Python
• Numpy

Installing this software on top of Ubuntu can be achieved using the following commands:

sudo apt-get install python python-numpy

For questions or comments, please contact Cristian Klein [email protected].