An adaptive system can automatically maintain its requirements in the presence of dynamic environment changes. Developing an adaptive system is difficult due to design time uncertainty, because how the environment will change at runtime and what precise effects adaptations will have on the running system are typically unknown at design time.
Online reinforcement learning, i.e., employing reinforcement learning (RL) at runtime, is an emerging approach to realize self-adaptive systems in the presence of design time uncertainty. Online RL learns via actual operational data and thereby leverages feedback only available at runtime.
Deep RL algorithms represent the learned knowledge as a neural network. Compared with classical RL algorithms, Deep RL algorithms offer important benefits for adaptive systems. Deep RL can generalize over unseen inputs, it can handle continuous environment states and adaptation actions, and it can readily capture concept and data drifts. Yet, a fundamental problem of Deep RL is that learned knowledge is not represented explicitly. For a human, it is practically impossible to relate neural network parameters to concrete RL decisions.
Understanding RL decisions is key to (1) increase trust, and (2) facilitate debugging. Debugging is especially relevant for adaptive systems, because the reward function, which quantifies the feedback to the RL algorithm, must explicitly defined by developers, thus introducing a source for human error.
We introduce XRL-DINE to make Deep RL decisions for self-adaptive systems explainable. XRL-DINE enhances and combines explainable RL techniques from machine
1 paluno, University of Duisburg-Essen, Essen, Germany, f.m.feit@gmail.com
2 paluno, University of Duisburg-Essen, Essen, Germany, andreas.metzger@paluno.uni-due.de
3 paluno, University of Duisburg-Essen, Essen, Germany, klaus.pohl@paluno.uni-due.de
2 Felix Feit, Andreas Metzger, Klaus Pohl
State S:
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DOWN -12,99 -13,00 -11,98 -10,95
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Abb. 1: Illustration of how learned knowledge is represented for Cliff Walk example from [SB18].
learning research. We present a proof-of-concept implementation of XRL-DINE, as well as qualitative and quantitative results that demonstrate the usefulness of XRL-DINE.
Beobachtung von Veränderungen in Umgebung, Anforderungen und sich selbst
Anpassungen von Struktur, Parametern und Verhalten
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M. Papazoglou, K. Pohl, M. Parkin, and A. Metzger, Eds., Service Research Challenges and Solutions for the Future Internet: S-Cube – Towards Mechanisms and Methods for Engineering, Managing, and Adapting Service-Based Systems, ser. LNCS. Heidelberg, Germany: Springer, 2010, vol. 6500.
Trotz dieser Möglichkeiten, zeigen sich beim Einsatz von ML für AS konkrete Probleme, von denen ich auf zwei im weiteren verlauf genauer eingehen werde…
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Bradley Schmerl, David Garlan, Christian Kästner - CMU
Danny Weyns – U Leuven
Pooyan Jamshidi – U South Carolina
Javier Camara – U York
Hongbing Wang – U Nanjing
Sven Tomforde – U Kiel
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N. Esfahani, E. Kouroshfar, and S. Malek, “Taming Uncertainty in Self-adaptive Software,” in Proceedings of the 19th ACM SIGSOFT Symposium and the 13th European Conference on Foundations of Software Engineering, ser. ESEC/FSE ’11, 2011, pp. 234–244.
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A. J. Ramirez, A. C. Jensen, and B. H. C. Cheng, “A taxonomy of uncertainty for dynamically adaptive systems,” in 7th International Symposium on Software Engineering for Adaptive and Self-Managing Systems, SEAMS, 2012, pp. 99–108.
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Cf. Mean efficiency of tool-supported debugging: 0.03; mean efficiency of requirement/design Inspections 0.06
Beobachtung von Veränderungen in Umgebung, Anforderungen und sich selbst
Anpassungen von Struktur, Parametern und Verhalten
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M. Papazoglou, K. Pohl, M. Parkin, and A. Metzger, Eds., Service Research Challenges and Solutions for the Future Internet: S-Cube – Towards Mechanisms and Methods for Engineering, Managing, and Adapting Service-Based Systems, ser. LNCS. Heidelberg, Germany: Springer, 2010, vol. 6500.