Building autonomic components: The SelfLets approach

Abstract

Autonomic computing is an emergent field aiming at the development of large-scale, self-managing, distributed component-based systems. This paper presents the model and the architecture of an autonomic computing element called SelfLet, which is a building component that can be used to create autonomic systems. SelfLets can be defined by specifying their goal, behaviors, services they need to use and/or provide, and autonomic policies guiding their self-management. The SelfLet architecture has been implemented in Java and offers programming abstractions suitable to implement an application-specific logic as well as autonomic policies. As a case study we have implemented a pervasive autonomic system that manages electrical power balancing in intelligent cooperating buildings.

Using Compositionality to Formally Model and Analyze Systems Built of a High Number of Components

“…In all these experiments we considered a system of just 3 SelfLets, and the range of item threshold is set to [1..2MAX C ], where MAX C is the maximum value for item consumption. Since we limit the number of SelfLets in the system, resources needed to prove step (12) in the compositional proofs are negligible, whereas all effort is for step (11) which instead depends on the ranges of the items. The experiments show clearly that the detailed model is more expensive than the original one in terms of the verification effort.…”

“…Table IV summarizes the results of this compositional verification of property P 2 for different values of N s , k, and scale (SC) factor. For every test, the time and space (T/S) of both steps 1 and 2 (corresponding to (11) and (12), respectively) is reported, as well as the totals for the whole compositional verification of P 2 . This shows that the complexity of the component-level check of (11) is independent of N s , as for P 1 .…”

“…The system is described in [11] and is based on an autonomic infrastructure and architectural model called SelfLets. According to the SelfLets model a software system is composed of various autonomous elements, each of which is a SelfLet.…”