Towards the description and execution of transitions in networked systems

Abstract

Today’s distributed systems have to work in changing environments and under different working conditions. To provide high performance under these changing conditions, many distributed systems implement adaptive behavior. While simple adaptation through parameter tuning can only react to a limited range of conditions, a switch between different mechanisms at runtime enables broader adaptivity. However, distributed systems that switch mechanisms at runtime lack a clear abstraction for the adaptive behavior and, thus, usually interleave the adaptation and actual application logic. This leads to complex and error-prone systems that are hard to maintain and not easy to extend. In this paper, we analyze the adaptations of two distributed systems from different application domains. We identify recurring requirements as well as life cycles of transitions between mechanisms. Based on this, we present a framework that provides a clear abstraction of the underlying transition logic and manages the transitions at runtime. The concept is applied to the two example systems to practically evaluate its benefits. We show that our approach leads to less complex realizations of the adaptive behavior and allows new mechanisms to be integrated easily.