|Control Action Types - Patterns of Central Control for Self-adaptive Systems
|Universitätsplatz 1, 31134 Hildesheim
|Software Systems Engineering, Institut für Informatik, Universität Hildesheim
|number / issue
|1/2022, SSE 1/22/E
An essential building block for any Self-adaptive System (SaS) is its inherent control mechanism. This mechanism enables a SaS to modify its domain functionality with respect to changes in its environment autonomously. Distributed control and central control represent two complementary paradigms to establish this capability. The selection of one of these paradigms leads to significant trade-offs regarding certain software qualities when designing a SaS. A promising approach to minimize these trade-offs is an integration, which combines the individual benefits to achieve the best of both paradigms. However, establishing such a multi-paradigm control requires comprehensive knowledge about control options and their interactions, which is hardly available.
In this report, we build on our previous work and present a pattern catalog for integrating distributed and central control. We introduce these patterns by a taxonomy of Control Action Types (CATs). Each CAT describes a unique type of interaction between a central controller and a distributed controlled SaS to achieve a desired adaptation. Further, we identify involved trade-offs between these CATs. While other approaches exist, which propose their individual integrations, we aim at a systematic discussion of the range of multi-paradigm control for a SaS.