Workload Characterization for Software Aging Analysis

The phenomenon of software aging is increasingly recognized as a relevant problem of long-running systems. Numerous experiments have been carried out in the last decade to empirically analyze software aging. Such experiments, besides highlighting the relevance of the phenomenon, have shown that aging is tightly related to the applied workload. However, due to the differences among the experimented applications and among the experimental conditions, results of past studies are not comparable to each other. This prevent from drawing general conclusions (e. g., about the aging-workload relationship), and from comparing systems from the aging perspective. In this paper, we propose a procedure to carry out aging experiments in different applications for: i) assessing aging trend of the individual systems, as well as assessing differences among them (i. e., obtaining comparable results); ii) inferring workload-aging relationships from experiments performed on different applications, by highlighting the most relevant workload parameters. The procedure is applied, through a set of long-running experiments, to three real-scale software applications, namely Apache Web Server, James Mail Server, and CARDAMOM, a middleware for the development of air traffic control (ATC) systems.