## 6 Genericity: Quantitative Analysis
Features that are only partially supported by CO framework or that are only offered by the commercial version are counted as a \(\frac{1}{2}\). \begin{table}
\begin{tabular}{l c c c} \hline \hline \multirow{2}{*}{**Aspects**} & **\#Common** & **\#Implementation** & **\#Unique** \\  & **Features** & **Strategies** & **Features** \\ \hline Application configuration and deployment & 29 & 130.5 & 10 \\ App and cluster management & 21 & 104 & 10 \\ Container networking & 20 & 82 & 8 \\ Container QoS Management & 15 & 69 & 6 \\ Cluster architecture and setup & 13 & 63 & 2 \\ Securing clusters & 9 & 36 & 4 \\ CO framework customization & 6 & 32 & 9 \\ Securing containers & 7 & 19.5 & 3 \\ Resource quota management & 4 & 12.5 & 1 \\ Total & 124 & 548.5 & 53 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Functional aspects ranked according to the number of common feature implementation strategies by CO frameworks. If a common feature is partially supported by or only supported in the commercial version of a CO framework, the implementation strategy is counted as \(\frac{1}{2}\). Finally, the number of common and unique features of each functional aspect are also presented. * Besides the main functional requirement of persistent storage, various orthogonal orchestration features for management of persistent volumes can be distinguished. Moreover, most of these features are supported by almost all CO frameworks. * The adoption of the Docker volume plugin architecture by Mesos-based systems as well as the CSI specification by Kubernetes and Mesos has also been recorded as an additional feature. Secondly the sub-aspect \"services networking\" counts also a high number of common features because of two similar reasons:  
* No less than 3 alternative approaches to services networking can be distinguished that are all supported by multiple CO frameworks and within each alternative approach one can distinguish at a lower nested level between different alternative load balancing strategies. * There are again two standardization initiatives related to this sub-aspect: Docker's libnetwork architecture and the CNI specification. _RQ5: How are CO frameworks ranked in terms of number of supported common features?_  
As shown in Figure 5, Kubernetes implements the highest number of common features, but also supports the highest number of unique features. _RQ6a. Which functional (sub)-aspects are best supported by a CO framework in terms of common features?_  
As shown in Figure 6, Kubernetes implements the highest number of common features for 6 aspects. Docker Swarm integrated mode supports the most common features for the aspects \"container networking\" and \"securing clusters\". Finally, DC/OS supports the most common features for the aspect \"application and cluster management\". Figure 5: Comparison of CO frameworks according to the total number of supported features. Features that are partially supported by a CO framework or that are only offered by the commercial version of the framework are counted as a \(\frac{1}{2}\). Table 5 presents an overview of the number of common feature implementation strategies per CO framework and per (sub)-aspect. We find significant differences in ranking between the frameworks when applying the Friedman test for unreplicated designs [56] (\(p\)-value = 2.668 \(\times\) 10\({}^{-8}\)). To deal with tied observations in this test, we compute ranks using R's rank() method where ranks for tied observations are replaced by their mean. We also performed during post-hoc analysis a pairwise comparison between CO frameworks using the Nemenyi multiple comparison test with q approximation for unreplicated blocked data [56] (see Figure 7). Based on the \(p\)-values of the Nemenyi test, we find that Docker Swarm stand-alone and Aurora differ significantly in genericity from both Kubernetes and DC/OS.