Auflistung nach Autor:in "Richling, Jan"
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- KonferenzbeitragAchieving scalability for job centric monitoring in a distributed infrastructure(ARCS 2012 Workshops, 2012) Hilbrich, Marcus; Müller-Pfefferkorn, RalphJob centric monitoring allows to observe jobs on remote computing resources. It may offer visualisation of recorded monitoring data and helps to find faulty or misbehaving jobs. If installations like grids or clouds are observed monitoring data of many thousands of jobs have to be handled. The challenge of job centric monitoring infrastructures is to store, search and access data collected in huge installations like grids or clouds. We take this challenge with a distributed layer based architecture which provides a uniform view to all monitoring data. The concept of this infrastructure called SLAte and an analysis of the scalability is provided in this paper.
- KonferenzbeitragAdapting the data organization of secondary storage in virtualized environments(INFORMATIK 2013 – Informatik angepasst an Mensch, Organisation und Umwelt, 2013) Jeremic, Nikolaus; Parzyjegla, Helge; Mühl, Gero; Richling, JanIn virtualized environments, multiple virtual machines (VMs) usually share a common secondary storage system which is, thus, often subject to a broad range of access patterns and different requirements (e.g., regarding performance, capacity, and reliability) imposed by diverse applications running inside the VMs. Moreover, with applications and VMs being added, started, stopped, and removed, access patterns as well as requirements may vary significantly over time. Ideally, the storage system is able to adapt to changing access patterns while considering application requirements at the same time. However, many storage systems only use a static data organization scheme in terms of drive assignment and data layout that is defined at deployment time, and may become disadvantageous or even inappropriate for the current workload. Although some storage systems employ data migration (e.g., dynamic storage tiering), the data layout remains unchanged due to a prohibitive high reorganization overhead. In this paper, we propose a mechanism for a fine-grained data organization adaptation that includes the data layout. This significantly extends the range of feasible adaptions compared to existing systems. Our approach factors application hints and requirements into adaptation decisions and exploits observations of access patterns as well as the state of the page cache to increase its effectiveness. Furthermore, we present a case study showing the benefits of fine-grained adaptations and discuss two options for the integration of the proposed adaptation mechanism into existing virtual machine monitors (VMMs), also known as hypervisors (HVs).
- KonferenzbeitragAdaptive content distribution network for live and on-demand streaming(ARCS 2012 Workshops, 2012) Miyauchi, Yuta; Matsumoto, Noriko; Yoshida, Norihiko; Kamiya, Yuko; Shimokawa, ToshihikoWe have proposed an adaptive content distribution network (CDN), FCAN (Flash Crowds Alleviation Network), which changes its structure dynamically against a flash crowd, that is a rapid increase in server load caused by a sudden access concentration. FCAN in our preceding studies responds only to static content delivery. In this paper, we extend FCAN to alleviate flash crowds in video streaming. Through some experiments, we confirmed that FCAN for video streaming is effective to alleviate flash crowds.
- KonferenzbeitragAn anonymous efficient private set intersection protocol for wireless sensor networks(ARCS 2012 Workshops, 2012) Moldovan, George; Ignat, AndaWe present an efficient protocol which, under certain assumptions, provides a suitable level of security and anonymity in the ideal cipher model when computing the intersection of two private data-sets containing lists of elements from a large domain. The assumptions are that each node is pre-loaded with a set of pseudonyms, signed by the network's trusted authority; that the cardinality of each data-set is globally known. Our protocol first establishes a secure, trusted connection between two partners, then uses lightweight, symmetrical key operations for encoding and privately comparing the elements of two sets. Given a cryptographically secure symmetric encryption scheme, our protocol is safe for both semi-honest and malicious adversaries. The primary target platform for this protocol are Wireless Sensor Networks (WSNs), specifically those used in Ambient Assisted Living (AAL) scenarios, which almost entirely consist of a heterogeneous mix of devices, providers and manufacturers.
- Editiertes BuchARCS 2012 Workshops(2012)
- KonferenzbeitragART networks as flexible means to implement dependability properties in autonomous systems(ARCS 2012 Workshops, 2012) Großpietsch, Karl-Erwin; Silayeva, Tanya A.In this paper, the potential of adaptive resonance theory (ART) networks for dependability issues is considered. The basic properties of ART architectures are described, and some strategies are discussed to enable a balanced combination of performance and dependability requirements by these networks.
- KonferenzbeitragCellular location determination - reliability and trustworthiness of GSM location data(ARCS 2012 Workshops, 2012) Zahoransky, Richard M.; Rechert, Klaus; Meier, Konrad; Wehrle, Dennis; Suchodoletz, Dirk vonWhile using mobile telephony networks, the serving network infrastructure is able to determine the mobile station's location. Until now, cellular telephony has been built on self-contained infrastructure, i.e. all network components have been certified and especially users have been unable to take over control over their mobile equipment's behavior. With the rising awareness on privacy issues, software-based mobile phone network stacks became available and thereby a new freedom degree for mobile subscribers is introduced. While slight modification to the mobile phones behavior will not impair with the general functionality of the network, cellular location determination becomes less reliable and trustworthy. We discuss user imposed measures to detect external location determination attempts and to obfuscate generated location information. With a dedicated testbed setup, the effects of location obfuscation were evaluated.
- KonferenzbeitragConcurrent phase classification for accelerating MPSoC simulation(ARCS 2012 Workshops, 2012) Tawk, Melhem; Ibrahim, Khaled Z.; Niar, SmailTo rapidly evaluate performances and power consumption in design space exploration of modern highly complex embedded systems, new simulation tools are needed. The checkpointing technique, which consists in saving system states in order to simulate in detail only a small part of the application, is among the most viable simulation approaches. In this paper, a new method for generating and storing checkpoints for accelerating MPSoC simulation is presented. Experimental results demonstrate that our technic can reduce simulation time and the memory size required to store these checkpoints on a secondary memory. In addition, the necessary time to load checkpoints on the host processor at runtime is optimized. These advantages speedup simulations and allow exploration of a large space of alternative designs in the DSE.
- KonferenzbeitragCorrection of faulty signal transmission for resilient designs of signed-digit arithmetic(ARCS 2012 Workshops, 2012) Neuhäuser, David; Zehendner, EberhardWhen arithmetic components are parallelized, fault-prone interconnections can tamper results significantly. Advances in feature size shrinking lead to a steady increase of errors caused by faulty transmission. We suggest to employ resilient data encoding schemes to offset these negative effects. Focusing on parallel signed-digit based arithmetic, frequently used in high-speed systems, we found that a suitable data encoding can reduce error rates by about 25% when using 2-bit encoding and about 62% when using 3-bit encoding. Data encoding should be driven by symbol occurrence probabilities. We develop a methodology to obtain these probabilities, show example fault-tolerant encodings, and discuss the impact on communicating parallel arithmetic circuits in example error scenarios.
- KonferenzbeitragEfficient memory allocations on a many-core accelerator(ARCS 2012 Workshops, 2012) Koutras, Ioannis; Bartzas, Alexandros; Soudris, DimitriosMemory management is one of the key challenges in the design of embedded systems where memory is a scarce resource. The problem scales disproportionally as new embedded systems incorporate many-core architectures where the cores have to struggle accessing an even more limited amount of resources. In this paper we present a way of creating custom memory allocators for many-core accelerators. We evaluated our approach in the P2012 platform, a many-core accelerator from ST. It is shown that a custom memory allocator created by our framework could save on average 62% of the total cycles spent on memory resource management when compared with the platform's current memory allocator without increasing the allocator's overhead.