TY  - JOUR
A1  - Kling, Christoph
A1  - Schneidenbach, Lars
A1  - Schnor, Bettina
T1  - A high performance gigabit ethernet messaging method for PVFS
N2  - Parallel File Systems like PVFS2 are a necessary compo nent for high-performance computing. The design of ef ;cient communication layers for these systems is still of great research interest. This paper presents a low- latency messaging method for PVFS2 dedicated for Gigabit Ether net networks and discusses relevant design issues. In con trast to other approaches, we argue that zero-copying can be achieved also for big messages without use of a rendez vous protocol. Further, ef;ciency within the communica tion layer like a small call stack plays an important role.
Y1  - 2005
SN  - 0-88986-525-6
ER  - 
TY  - JOUR
A1  - Liang, Feng
A1  - Liu, Yunzhen
A1  - Liu, Hai
A1  - Ma, Shilong
A1  - Schnor, Bettina
T1  - A Parallel Job Execution Time Estimation Approach Based on User Submission Patterns within Computational Grids
JF  - International journal of parallel programming
N2  - Scheduling performance in computational grid can potentially benefit a lot from accurate execution time estimation for parallel jobs. Most existing approaches for the parallel job execution time estimation, however, require ample past job traces and the explicit correlations between the job execution time and the outer layout parameters such as the consumed processor numbers, the user-estimated execution time and the job ID, which are hard to obtain or reveal. This paper presents and evaluates a novel execution time estimation approach for parallel jobs, the user-behavior clustering for execution time estimation, which can give more accurate execution time estimation for parallel jobs through exploring the job similarity and revealing the user submission patterns. Experiment results show that compared to the state-of-art algorithms, our approach can improve the accuracy of the job execution time estimation up to 5.6 %, meanwhile the time that our approach spends on calculation can be reduced up to 3.8 %.
KW  - User submission pattern
KW  - Parallel job execution time estimation
KW  - Computational grid
Y1  - 2015
U6  - https://doi.org/10.1007/s10766-013-0294-1
SN  - 0885-7458
SN  - 1573-7640
VL  - 43
IS  - 3
SP  - 440
EP  - 454
PB  - Springer
CY  - New York
ER  - 
TY  - JOUR
A1  - Luckow, Andre
A1  - Jha, Shantenu
A1  - Kim, Joohyun
A1  - Merzky, Andre
A1  - Schnor, Bettina
T1  - Adaptive distributed replica-exchange simulations
N2  - Owing to the loose coupling between replicas, the replica-exchange (RE) class of algorithms should be able to benefit greatly from using as many resources as available. However, the ability to effectively use multiple distributed resources to reduce the time to completion remains a challenge at many levels. Additionally, an implementation of a pleasingly distributed algorithm such as replica-exchange, which is independent of infrastructural details, does not exist. This paper proposes an extensible and scalable framework based on Simple API for Grid Applications that provides a general-purpose, opportunistic mechanism to effectively use multiple resources in an infrastructure-independent way. By analysing the requirements of the RE algorithm and the challenges of implementing it on real production systems, we propose a new abstraction (BIGJOB), which forms the basis of the adaptive redistribution and effective scheduling of replicas.
Y1  - 2009
UR  - http://rsta.royalsocietypublishing.org/
U6  - https://doi.org/10.1098/rsta.2009.0051
SN  - 1364-503X
ER  - 
TY  - JOUR
A1  - Schneidenbach, Lars
A1  - Schnor, Bettina
A1  - Petri, Stefan
T1  - Architecture and Implementation of the Socket Interface on Top of GAMMA
Y1  - 2003
SN  - 0-7695-2037-5
ER  - 
TY  - JOUR
A1  - Lanfermann, Gerd
A1  - Schnor, Bettina
A1  - Seidel, Edward
T1  - Characterizing Grids
N2  - We present a new data model approach to describe the various objects that either represent the Grid infrastructure or make use of it. The data model is based on the experiences and experiments conducted in heterogeneous Grid environments. While very sophisticated data models exist to describe and characterize e.g. compute capacities or web services, we will show that a general description, which combines {em all} of these aspects, is needed to give an adequate representation of objects on a Grid. The Grid Object Description Language (GODsL)} is a generic and extensible approach to unify the various aspects that an object on a Grid can have. GODsL provides the content for the XML based communication in Grid migration scenarios, carried out in the GridLab project. We describe the data model architecture on a general level and focus on the Grid application scenarios.
Y1  - 2003
SN  - 1-4020-7418-2
ER  - 
TY  - JOUR
A1  - Kiertscher, Simon
A1  - Zinke, Jörg
A1  - Schnor, Bettina
T1  - CHERUB power consumption aware cluster resource management
JF  - Cluster computing : the journal of networks, software tools and applications
N2  - This paper presents an evaluation of ACPI energy saving modes, and deduces the design and implementation of an energy saving daemon for clusters called cherub. The design of the cherub daemon is modular and extensible. Since the only requirement is a central approach for resource management, cherub is suited for Server Load Balancing (SLB) clusters managed by dispatchers like Linux Virtual Server (LVS), as well as for High Performance Computing (HPC) clusters. Our experimental results show that cherub's scheduling algorithm works well, i.e. it will save energy, if possible, and avoids state-flapping.
KW  - Green computing
KW  - Cluster computing
Y1  - 2013
U6  - https://doi.org/10.1007/s10586-011-0176-5
SN  - 1386-7857
VL  - 16
IS  - 1
SP  - 55
EP  - 63
PB  - Springer
CY  - New York
ER  - 
TY  - JOUR
A1  - Lorenz, Claas
A1  - Clemens, Vera Elisabeth
A1  - Schrötter, Max
A1  - Schnor, Bettina
T1  - Continuous verification of network security compliance
JF  - IEEE transactions on network and service management
N2  - Continuous verification of network security compliance is an accepted need. Especially, the analysis of stateful packet filters plays a central role for network security in practice. But the few existing tools which support the analysis of stateful packet filters are based on general applicable formal methods like Satifiability Modulo Theories (SMT) or theorem prover and show runtimes in the order of minutes to hours making them unsuitable for continuous compliance verification. In this work, we address these challenges and present the concept of state shell interweaving to transform a stateful firewall rule set into a stateless rule set. This allows us to reuse any fast domain specific engine from the field of data plane verification tools leveraging smart, very fast, and domain specialized data structures and algorithms including Header Space Analysis (HSA). First, we introduce the formal language FPL that enables a high-level human-understandable specification of the desired state of network security. Second, we demonstrate the instantiation of a compliance process using a verification framework that analyzes the configuration of complex networks and devices - including stateful firewalls - for compliance with FPL policies. Our evaluation results show the scalability of the presented approach for the well known Internet2 and Stanford benchmarks as well as for large firewall rule sets where it outscales state-of-the-art tools by a factor of over 41.
KW  - Security
KW  - Tools
KW  - Network security
KW  - Engines
KW  - Benchmark testing;
KW  - Analytical models
KW  - Scalability
KW  - Network
KW  - security
KW  - compliance
KW  - formal
KW  - verification
Y1  - 2021
U6  - https://doi.org/10.1109/TNSM.2021.3130290
SN  - 1932-4537
VL  - 19
IS  - 2
SP  - 1729
EP  - 1745
PB  - Institute of Electrical and Electronics Engineers
CY  - New York
ER  - 
TY  - JOUR
A1  - Schneidenbach, Lars
A1  - Schnor, Bettina
T1  - Design Issues in the Implementation of MPI2 One Sided Communication in Ethernet based Networks
N2  - In current research, one sided communication of the MPI2 standard is pushed as a promising technique [6, 7, 10, 18]. But measurements of applications and MPI2 primitives show a different picture [17]. In this paper we analyze de sign issues of MPI2 one sided communication and its im plementations. We focus on asynchronous communication for parallel applications in Ethernet cluster environments. Further, one sided communication is compared to two sided communication. This paper will prove that the key problem to performance is not only the implementation of MPI2 one sided communication - it is the design.
Y1  - 2007
SN  - 978-0-88986-637-9
ER  - 
TY  - JOUR
A1  - Vandenhouten, Ralf
A1  - Behrens, Thomas
A1  - Schnor, Bettina
T1  - Entwicklung eines Gatewaysystems für telematikbasiertes Gerätemonitoring
Y1  - 2004
SN  - 0949-8214
ER  - 
TY  - JOUR
A1  - Ciaccio, Giuseppe
A1  - Ehlert, Marco
A1  - Schnor, Bettina
T1  - Exploiting gigabit ethernet capacity for cluster applications
N2  - In this paper we report about the recently completed porting of GAMMA to the Netgear GA621 Gigabit Ethernet adapter, and provide a comparison among GAMMA, MPI/GAMMA, TCP/IP, and MPICH/TCP, based on the Netgear GA621 and the older Netgear GA620 network adapters and using different device drivers, in a Gigabit Ethernet cluster of PCs running Linux 2.4. GAMMA (the Genoa Active Message MAchine) is a lightweight messaging system based on an Active Message-like paradigm, originally designed for efficient exploitation of Fast Ethernet interconnects. The comparison includes simple latency/hspace{0pt}bandwidth evaluation of the messaging systems on both adapters, as well as performance comparisons based on the NAS NPB and an end-user fluid dynamics application called Modular Ocean Model (MOM). The analysis of results provides useful hints concerning the efficient use of Gigabit Ethernet with clusters of PCs. In particular, it emerges that GAMMA on the GA621 adapter, with a combination of low end-to-end latency (8.5 $mu$s) and high throughput (118.4 MByte/s), provides a performing, cost-effective alternative to proprietary high-speed networks, e.g.~Myrinet, for a wide range of cluster computing applications.
Y1  - 2002
SN  - 0-7695-1591-6
ER  - 
TY  - JOUR
A1  - Christgau, Steffen
A1  - Schnor, Bettina
T1  - Exploring one-sided communication and synchronization on a non-cache-coherent many-core architecture
JF  - Concurrency and computation : practice & experience
N2  - The ongoing many-core design aims at core counts where cache coherence becomes a serious challenge. Therefore, this paper discusses how one-sided communication and the required process synchronization can be realized on a non-cache-coherent many-core CPU. The Intel Single-chip Cloud Computer serves as an exemplary hardware architecture. The presented approach is based on software-managed cache coherence for MPI one-sided communication. The prototype implementation delivers a PUT performance of up to 5 times faster than the default message-based approach and reveals a reduction of the communication costs for the NAS Parallel Benchmarks 3-D fast Fourier Transform by a factor of 5. Further, the paper derives conclusions for future non-cache-coherent architectures.
KW  - MPI
KW  - one-sided communication
KW  - programming models and systems for many-cores
KW  - synchronization
KW  - software-managed cache coherence
Y1  - 2017
U6  - https://doi.org/10.1002/cpe.4113
SN  - 1532-0626
SN  - 1532-0634
VL  - 29
PB  - Wiley
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Hoheisel, A.
A1  - Müller, S.
A1  - Schnor, Bettina
T1  - Fine-grained Security Management in a Service-oriented Grid Architecture
Y1  - 2007
UR  - http://www.cyfronet.krakow.pl/cgw06/presentations/c4-3.pdf
SN  - 978-0-387-72811-7
ER  - 
TY  - JOUR
A1  - Hallama, Nicole
A1  - Luckow, André
A1  - Schnor, Bettina
T1  - Grid Security for Fault Tolerant Grid Applications
Y1  - 2006
SN  - 978-1-880843-60-4
ER  - 
TY  - JOUR
A1  - Feider, Henryk
A1  - Schnor, Bettina
A1  - Dramlitsch, Thomas
T1  - Gridmake : the missing link for compilation in the Grid
N2  - In order to take full advantage of Grid environments, applications need to be able to run on various heterogeneous platforms. Distributed runs across several clusters or supercomputers for example, require matching binaries at each site. Thus, at some stage, each Grid enabled application needs to be recompiled for every platform. Up to now, creating matching binaries on different platforms was a manual, sequential, slow, and very error-prone process. Developers had to log into each machine, transfer source code, check consistency and recompile if necessary. This cumbersome procedure is surely one reason for the (still existing) lack of production Grid computing. Gridmake, a tool to automate and speed up this procedure is presented in this paper.
Y1  - 2003
ER  - 
TY  - JOUR
A1  - Friedrich, Sven
A1  - Krahmer, Sebastian
A1  - Schneidenbach, Lars
A1  - Schnor, Bettina
T1  - Loaded : Server Load Balancing for IPv6
Y1  - 2004
ER  - 
TY  - JOUR
A1  - Friedrich, Sven
A1  - Krahmer, Sebastian
A1  - Schneidenbach, Lars
A1  - Schnor, Bettina
T1  - Loaded: Server Load Balancing for IPv6
N2  - With the next generation Internet protocol IPv6 at the horizon, it is time to think about how applications can migrate to IPv6. Web traffic is currently one of the most important applications in the Internet. The increasing popularity of dynamically generated content on the World Wide Web, has created the need for fast web servers. Server clustering together with server load balancing has emerged as a promising technique to build scalable web servers. The paper gives a short overview over the new features of IPv6 and different server load balancing technologies. Further, we present and evaluate Loaded, an user-space server load balancer for IPv4 and IPv6 based on Linux.
Y1  - 2006
SN  - 0-7695-2622-5
ER  - 
TY  - JOUR
A1  - Luckow, André
A1  - Schnor, Bettina
T1  - Migol : a Fault Tolerant Service Framework for Grid Computing : Evolution to WSRF (2006)
Y1  - 2006
ER  - 
TY  - JOUR
A1  - Luckow, André
A1  - Schnor, Bettina
T1  - Migol : a Fault-Tolerant Service Framework for MPI Applications in the Grid
N2  - In a distributed, inherently dynamic Grid environment the reliability of individual resources cannot be guaranteed. The more resources and components are involved the more error-prone is the system. Therefore, it is important to enhance the dependability of the system with fault-tolerance mechanisms. In this paper, we present Migol, a fault-tolerant, self-healing Grid service infrastructure for MPI applications. The benefit of the Grid is that in case of a failure an application may be migrated and restarted from a checkpoint file on another site. This approach requires a service infrastructure which handles the necessary activities transparently for an application. But any migration framework cannot support fault-tolerant applications, if it is not fault-tolerant itself.
Y1  - 2005
SN  - 978-3-540-29009-4
ER  - 
TY  - JOUR
A1  - Luckow, André
A1  - Schnor, Bettina
T1  - Migol : a fault-tolerant service framework for MPI applications in the grid
N2  - Especially for sciences the provision of massive parallel CPU capacity is one of the most attractive features of a grid. A major challenge in a distributed, inherently dynamic grid is fault tolerance. The more resources and components involved, the more complicated and error-prone becomes the system. In a grid with potentially thousands of machines connected to each other the reliability of individual resources cannot be guaranteed.The benefit of the grid is that in case of a failure ail application may be migrated and restarted from a checkpoint file on another site. This approach requires a service infrastructure which handles the necessary activities transparently. In this article, we present Migol, a fault-tolerant and self-healing grid middleware for MPI applications. Migol is based on open standards and extends the services of the Globus toolkit to support the fault tolerance of grid applications.Further, the Migol framework itself is designed with special focus on fault tolerance. For example, Migol eplicates ritical services and uses a ring-based replication protocol to achieve data consistency. (c) 2007 Elsevier B.V. All rights reserved.
Y1  - 2008
U6  - https://doi.org/10.1016/j.future.2007.03.007
ER  - 
TY  - JOUR
A1  - Schneidenbach, Lars
A1  - Schnor, Bettina
T1  - Migration of MPI Applications to IPv6 Networks
Y1  - 2005
SN  - 0-88986-468-3
ER  -