Blazes: Coordination Analysis for Distributed Programs

Distributed consistency is perhaps the most discussed topic in distributed systems today. Coordination protocols can ensure consistency, but in practice they cause undesirable performance unless used judiciously. Scalable distributed architectures avoid coordination whenever possible, but under-coordinated systems can exhibit behavioral anomalies under fault, which are often extremely difficult to debug. This raises significant challenges for distributed system architects and developers. In this paper we present Blazes, a cross-platform program analysis framework that (a) identifies program locations that require coordination to ensure consistent executions, and (b) automatically synthesizes application-specific coordination code that can significantly outperform general-purpose techniques. We present two case studies, one using annotated programs in the Twitter Storm system, and another using the Bloom declarative language.Comment: Updated to include additional materials from the original technical report: derivation rules, output stream label

Dynamic Honeypot Configuration for Programmable Logic Controller Emulation

Attacks on industrial control systems and critical infrastructure are on the rise. Important systems and devices like programmable logic controllers are at risk due to outdated technology and ad hoc security measures. To mitigate the threat, honeypots are deployed to gather data on malicious intrusions and exploitation techniques. While virtual honeypots mitigate the unreasonable cost of hardware-replicated honeypots, these systems often suffer from a lack of authenticity due to proprietary hardware and network protocols. In addition, virtual honeynets utilizing a proxy to a live device suffer from performance bottlenecks and limited scalability. This research develops an enhanced, application layer emulator capable of alleviating honeynet scalability and honeypot inauthenticity limitations. The proposed emulator combines protocol-agnostic replay with dynamic updating via a proxy. The result is a software tool which can be readily integrated into existing honeypot frameworks for improved performance. The proposed emulator is evaluated on traffic reduction on the back-end proxy device, application layer task accuracy, and byte-level traffic accuracy. Experiments show the emulator is able to successfully reduce the load on the proxy device by up to 98% for some protocols. The emulator also provides equal or greater accuracy over a design which does not use a proxy. At the byte level, traffic variation is statistically equivalent while task success rates increase by 14% to 90% depending on the protocol. Finally, of the proposed proxy synchronization algorithms, templock and its minimal variant are found to provide the best overall performance

Middleware-based Database Replication: The Gaps between Theory and Practice

The need for high availability and performance in data management systems has been fueling a long running interest in database replication from both academia and industry. However, academic groups often attack replication problems in isolation, overlooking the need for completeness in their solutions, while commercial teams take a holistic approach that often misses opportunities for fundamental innovation. This has created over time a gap between academic research and industrial practice. This paper aims to characterize the gap along three axes: performance, availability, and administration. We build on our own experience developing and deploying replication systems in commercial and academic settings, as well as on a large body of prior related work. We sift through representative examples from the last decade of open-source, academic, and commercial database replication systems and combine this material with case studies from real systems deployed at Fortune 500 customers. We propose two agendas, one for academic research and one for industrial R&D, which we believe can bridge the gap within 5-10 years. This way, we hope to both motivate and help researchers in making the theory and practice of middleware-based database replication more relevant to each other.Comment: 14 pages. Appears in Proc. ACM SIGMOD International Conference on Management of Data, Vancouver, Canada, June 200

Fidelity Description Requirements For Distributed Interactive Simulation: IEEE Standard

Report establishes the standard for the fidelity correlation requirements for simulators participating in a distributed interactive simulation