Evaluating Scalable Distributed Erlang for Scalability and Reliability

Large scale servers with hundreds of hosts and tens of thousands of cores are becoming common. To exploit these platforms software must be both scalable and reliable, and distributed actor languages like Erlang are a proven technology in this area. While distributed Erlang conceptually supports the engineering of large scale reliable systems, in practice it has some scalability limits that force developers to depart from the standard language mechanisms at scale. In earlier work we have explored these scalability limitations, and addressed them by providing a Scalable Distributed (SD) Erlang library that partitions the network of Erlang Virtual Machines (VMs) into scalable groups (s_groups). This paper presents the first systematic evaluation of SD Erlang s_groups and associated tools, and how they can be used. We present a comprehensive evaluation of the scalability and reliability of SD Erlang using three typical benchmarks and a case study. We demonstrate that s_groups improve the scalability of reliable and unreliable Erlang applications on up to 256 hosts (6,144 cores). We show that SD Erlang preserves the class-leading distributed Erlang reliability model, but scales far better than the standard model. We present a novel, systematic, and tool-supported approach for refactoring distributed Erlang applications into SD Erlang. We outline the new and improved monitoring, debugging and deployment tools for large scale SD Erlang applications. We demonstrate the scaling characteristics of key tools on systems comprising up to 10 K Erlang VMs

CMQ - A lightweight, asynchronous high-performance messaging queue for the cloud

In cloud computing environments guarantees, consistency mechanisms, (shared) state and transactions are frequently traded for robustness, scalability and performance. Based on this challenge we present CMQ, a UDP-based inherently asynchronous message queue to orchestrate messages, events and processes in the cloud. CMQ's inherently asynchronous design is shown to perform especially well in modern Layer 2 switches in data center networks, as well as in the presence of errors. CMQ's lightweight edge-to-edge design, which is somewhat similar to Unix Pipes, makes it very composable. By presenting our work, we hope to initiate discussion on how to implement lightweight messaging paradigms that are aligned with the overall architectures and goals of cloud computing

Knowledge-Intensive Processes: Characteristics, Requirements and Analysis of Contemporary Approaches

Engineering of knowledge-intensive processes (KiPs) is far from being mastered, since they are genuinely knowledge- and data-centric, and require substantial flexibility, at both design- and run-time. In this work, starting from a scientific literature analysis in the area of KiPs and from three real-world domains and application scenarios, we provide a precise characterization of KiPs. Furthermore, we devise some general requirements related to KiPs management and execution. Such requirements contribute to the definition of an evaluation framework to assess current system support for KiPs. To this end, we present a critical analysis on a number of existing process-oriented approaches by discussing their efficacy against the requirements

Access Control from an Intrusion Detection Perspective

Access control and intrusion detection are essential components for securing an organization's information assets. In practice, these components are used in isolation, while their fusion would contribute to increase the range and accuracy of both. One approach to accomplish this fusion is the combination of their security policies. This report pursues this approach by defining a comparison framework for policy specification languages and using this to survey the languages Ponder, LGI, SPL and PDL from the perspective of intrusion detection. We identified that, even if an access control language has the necessary ingredients for merging policies, it might not be appropriate due to mismatches in overlapping concepts