Abstract
Various services are now available in the Cloud, ranging from turnkey databases and application servers to high-level
services such as continuous integration or source version control. To stand out of this diversity, robustness of service
compositions is an important selling argument, but which remains difficult to understand and estimate as it does not
only depend on services but also on the underlying platform and infrastructure. Yet, choosing a specific service
composition may fail to deliver the expected robustness, but reverting early choices may jeopardise the success of
any Cloud project.
Inspired by existing models used in Biology to quantify the robustness of ecosystems, we show how to tailor them to
obtain early indicators of robustness for cloud-based deployments. This technique helps identify weakest parts in the
overall architecture and in turn mitigates the risk of having to revert key architectural choices.We illustrate our approach
by comparing the robustness of four alternative deployments of the SensApp application, which includes a MongoDB
database, four REST services and a graphical web-front end.
services such as continuous integration or source version control. To stand out of this diversity, robustness of service
compositions is an important selling argument, but which remains difficult to understand and estimate as it does not
only depend on services but also on the underlying platform and infrastructure. Yet, choosing a specific service
composition may fail to deliver the expected robustness, but reverting early choices may jeopardise the success of
any Cloud project.
Inspired by existing models used in Biology to quantify the robustness of ecosystems, we show how to tailor them to
obtain early indicators of robustness for cloud-based deployments. This technique helps identify weakest parts in the
overall architecture and in turn mitigates the risk of having to revert key architectural choices.We illustrate our approach
by comparing the robustness of four alternative deployments of the SensApp application, which includes a MongoDB
database, four REST services and a graphical web-front end.
