Lightweight tracing for wireless sensor networks diagnostics

Wireless sensor networks (WSNs) are being increasingly deployed in various scientific as well as industrial domains to understand the micro-behavior of physical phenomena. WSNs are highly susceptible to post-deployment failures due to their in-situ deployments in harsh environments e.g., volcanoes. The traditional tools and techniques to handle such failures are inadequate because of inherent resource constraints of WSNs. The lack of diagnosis tools for post-deployment failures hinders the more widespread adoption of WSNs. An execution trace containing events in their order of execution can play a crucial role in postmortem diagnosis of these failures. Obtaining such a trace, however, is challenging due to stringent resource constraints. In this dissertation, we propose an efficient distributed control-flow tracing technique for WSNs based on two key observations. First, WSN executions are highly repetitive, and second, WSNs exhibit restricted communication patterns. Our distributed control-flow tracing combines three novel lightweight techniques: (1) an efficient interprocedural control-flow encoding technique that generates a succinct control-flow trace of all events happening within a node, (2) a generic hybrid trace compression technique that significantly compresses traces, and (3) a space efficient message tracing technique that is amenable to compression. We show our tracing technique\u27s effectiveness through failure case studies and efficiency through measurements and simulations

Lightweight Message Tracing for Debugging Wireless Sensor Networks

Abstract—Wireless sensor networks (WSNs) deployments are subjected not infrequently to complex runtime failures that are difficult to diagnose. Alas, debugging techniques for traditional distributed systems are inapplicable because of extreme resource constraints in WSNs, and existing WSN-specific debugging solutions address either only specific types of failures, focus on individual nodes, or exhibit high overheads hampering their scalability. Message tracing is a core issue underlying the efficient and effective debugging of WSNs. We propose a message tracing solution which addresses key challenges in WSNs — besides stringent resource constraints, these include out-of-order message arrivals and message losses — while being streamlined for the common case of successful in-order message transmission. Our approach reduces energy overhead significantly (up to 95 % and on average 59 % smaller) compared to state-of-theart message tracing approaches making use of Lamport clocks. We demonstrate the effectiveness of our approach through case studies of several complex faults in three well-known distributed protocols. I

Efficient diagnostic tracing for wireless sensor networks

Wireless sensor networks are typically deployed in harsh environments, thus post-deployment failures are not infrequent. An execution trace containing events in their order of execution could play a crucial role in postmortem diagnosis of these failures. Obtaining such a trace however is challenging due to stringent resource constraints. We propose an efficient approach to intraprocedural and interprocedural control-flow tracing that generates traces of all interleaving concurrent events and of the control-flow paths taken inside those events. We demonstrate the effectiveness of our approach with the help of case studies and illustrate its low overhead through measurements and simulations

SeNDORComm: An Energy-Efficient Priority-Driven Communication Layer for Reliable Wireless Sensor Networks

In many reliable Wireless Sensor Network (WSN) applications, messages have different priorities depending on urgency or importance. For example, a message reporting the failure of all nodes in a region is more important than that for a single node. Moreover, traffic can be bursty in nature, such as when a correlated error is reported by multiple nodes running identical code. Current communication layers in WSNs lack efficient support for these two requirements. We present a priority-driven communication layer, called SeNDORComm, that schedules transmission of packets driven by application-specified priority, buffers and packs multiple messages in a packet, and honors latency guarantee for a message. We show that SeNDORComm improves energy efficiency, message reliability, network utilization and delays congestion collapse in a network. We extensively evaluate SeNDORComm using analysis, simulation and real experiments. We demonstrate the improvement in goodput of SeNDORComm over a default communication layer (134.78% for a network of 20 nodes), such as GenericComm in TinyOS