Collecting and Analyzing Failure Data of Bluetooth Personal Area Networks

This work presents a failure data analysis campaign on Bluetooth Personal Area Networks (PANs) conducted on two kind of heterogeneous testbeds (working for more than one year). The obtained results reveal how failures distribution are characterized and suggest how to improve the dependability of Bluetooth PANs. Specically, we dene the failure model and we then identify the most effective recovery actions and masking strategies that can be adopted for each failure. We then integrate the discovered recovery actions and masking strategies in our testbeds, improving the availability and the reliability of 3.64% (up to 36.6%) and 202% (referred to the Mean Time To Failure), respectively

Integrated Support for Handoff Management and Context-Awareness in Heterogeneous Wireless Networks

The overwhelming success of mobile devices and wireless communications is stressing the need for the development of mobility-aware services. Device mobility requires services adapting their behavior to sudden context changes and being aware of handoffs, which introduce unpredictable delays and intermittent discontinuities. Heterogeneity of wireless technologies (Wi-Fi, Bluetooth, 3G) complicates the situation, since a different treatment of context-awareness and handoffs is required for each solution. This paper presents a middleware architecture designed to ease mobility-aware service development. The architecture hides technology-specific mechanisms and offers a set of facilities for context awareness and handoff management. The architecture prototype works with Bluetooth and Wi-Fi, which today represent two of the most widespread wireless technologies. In addition, the paper discusses motivations and design details in the challenging context of mobile multimedia streaming applications

Towards Secure Monitoring and Control Systems: Diversify!

This work discusses the role of diversity as a mean towards secure monitoring and control. The intuition underlying the proposal is that diversity can be leveraged to raise the effort it takes to conduct a successful attack (in terms of attack resources and time) to such a level so as to make it pointless to attempt an attack at all. For example, let us consider an attack that requires compromising two machines in order to be successful. If the machines are identical, it suffices to compromise one machine and then repeating the exploit for the other, i.e., the chance of a successful attack PSA to the system is related to the chance of compromising just one machine (PSA≈PM). When the machines are different, PSA is smaller because it becomes somewhat related to chance of compromising each machine separately (i.e., PSA≈PM1×PM2): succeeding is harder and time-consuming. Diversity is not used here to replicate components. We claim that a monitoring and control system, when possible, can smartly combine diverse technologies to significantly increase the effort to conduct a successful attack. Key aspects, issues and future research directions are briefly discussed in the following

An Effective Approach for Injecting Faults in Wireless Sensor Networks Operating Systems

This paper presents an effective approach for injecting faults/errors in WSN nodes operating systems. The approach is based on the injection of faults at the assembly level. Results show that depending on the concurrency model and on the memory management, the operating systems react to injected errors differently, indicating that fault containment strategies and hang-checking assertions should be implemented to avoid spreading and activations of errors

Unexplained cardiac arrest after near drowning in a young experienced swimmer: insight from cardiovascular magnetic resonance imaging

Cardiac magnetic resonance imaging (cMRI) is a well-established noninvasive imaging modality in clinical cardiology. Its ability to provide tissue characterization make it well suited for the study of patients with cardiac diseases. We describe a multi-modality imaging evaluation of a 45-year-old man who experienced a near drowning event during swimming. We underline the unique capability of tissue characterization provided by cMRI, which allowed detection of subtle, clinically unrecognizable myocardial damage for understanding the causes of sudden cardiac arrest and also showed the small damages caused by cardiopulmonary resuscitation

Dependability Evaluation of Middleware Technology for Large-scale Distributed Caching

Distributed caching systems (e.g., Memcached) are widely used by service providers to satisfy accesses by millions of concurrent clients. Given their large-scale, modern distributed systems rely on a middleware layer to manage caching nodes, to make applications easier to develop, and to apply load balancing and replication strategies. In this work, we performed a dependability evaluation of three popular middleware platforms, namely Twemproxy by Twitter, Mcrouter by Facebook, and Dynomite by Netflix, to assess availability and performance under faults, including failures of Memcached nodes and congestion due to unbalanced workloads and network link bandwidth bottlenecks. We point out the different availability and performance trade-offs achieved by the three platforms, and scenarios in which few faulty components cause cascading failures of the whole distributed system.Comment: 2020 IEEE 31st International Symposium on Software Reliability Engineering (ISSRE 2020

Monitoring of Aging Software Systems Affected by Integer Overflows

Numerical aging-related bugs, which can manifest themselves as the accumulation of floating-point errors and the overflow of integers, represent a known but relatively neglected issue in the field of software aging and rejuvenation. Unfortunately, it is very difficult to avoid and to fix these bugs, since the rules of computer arithmetic and programming languages are often misunderstood or disregarded by programmers. Even though software rejuvenation can potentially mitigate these problems, its adoption is prevented by the lack of approaches for forecasting numerical software aging failures: in order to efficiently plan rejuvenation, the rate of numerical errors has to be known, or at least estimated. In this paper, we focus on software aging phenomena related to integer overflows. We present some examples of integer overflow issues of the MySQL open-source DBMS, and an approach for identifying symptoms of potential integer overflows by on-line monitoring