For large-scale distributed systems that need to adapt to a changing environment, conducting a reconfiguration is a challenging task. In particular, efficient reconfigurations require the coordination of multiple tasks with complex dependencies. We present Concerto, a model used to manage the lifecycle of software components and coordinate their reconfiguration operations. Concerto promotes efficiency with a fine-grained representation of dependencies and parallel execution of reconfiguration actions, both within components and between them. In this paper, the elements of the model are described as well as their formal semantics. In addition, we outline a performance model that can be used to estimate the time required by reconfigurations, and we describe an implementation of the model. The evaluation demonstrates the accuracy of the performance estimations, and illustrates the performance gains provided by the execution model of Concerto compared to state-of-the-art systems.

对于需要适应不断变化的环境的大规模分布式系统，进行重新配置是一项艰巨的任务。特别是，有效的重新配置要求协调具有复杂依赖性的多个任务。我们介绍了Concerto，该模型用于管理软件组件的生命周期并协调其重新配置操作。协奏曲通过在组件内部以及组件之间的依赖关系的精细表示和重新配置动作的并行执行来提高效率。在本文中，描述了模型的元素及其形式语义。此外，我们概述了可用于估计重新配置所需时间的性能模型，并描述了该模型的实现。