{"id":359,"date":"2023-02-18T08:00:05","date_gmt":"2023-02-18T08:00:05","guid":{"rendered":"https:\/\/christian-engelmann.de\/?page_id=359"},"modified":"2023-02-19T01:01:54","modified_gmt":"2023-02-19T01:01:54","slug":"2004-07-molar-modular-linux-and-adaptive-runtime-support-for-high-end-computing","status":"publish","type":"page","link":"https:\/\/www.christian-engelmann.info\/?page_id=359","title":{"rendered":"2004-07: MOLAR: Modular Linux and Adaptive Runtime Support for High-End Computing"},"content":{"rendered":"<p>This project is a multi-institution research effort that targets adaptive, reliable, and efficient operating and runtime system solutions for ultra-scale high-end scientific computing on the next generation of supercomputers. It addresses the challenges outlined by the U.S. Department of Energy (DOE) Forum to Address Scalable Technology for Runtime and Operating Systems (FAST-OS) and the U.S. National Coordination Office for Networking and Information Technology Research and Development (NCO\/NITRD) High-End Computing Revitalization Task Force (HECRTF) activities by providing an adaptable runtime support for high-end computing operating and runtime systems. This research primarily concentrates on advancing computer reliability, availability and serviceability (RAS) management systems to run large and long-running applications efficiently on future ultra-scale computers, and on providing advanced monitoring and adaptation mechanisms for improved application performance and predictability.<\/p>\n<h4>Prominent Solutions<\/h4>\n<ul>\n<li><a href=\"?page_id=462\">Hybrid Full\/Incremental System-level Checkpointing<\/a><\/li>\n<li><a href=\"?page_id=457\">Symmetric Active\/Active High Availability for HPC System Services<\/a><\/li>\n<\/ul>\n<h4>Funding Sources<\/h4>\n<ul>\n<li>\n<a href=\"http:\/\/science.energy.gov\/ascr\" target=\"science.energy.gov_ascr\" rel=\"noopener\">Office of Advanced Scientific Computing Research<\/a>, Office of Science, U.S. Department of Energy<\/li>\n<\/ul>\n<h4>Participating Institutions<\/h4>\n<ul>\n<li><a href=\"http:\/\/www.ornl.gov\" target=\"www.ornl.gov\" rel=\"noopener\">Oak Ridge National Laboratory<\/a><\/li>\n<li><a href=\"http:\/\/www.ncsu.edu\" target=\"www.ncsu.edu\" rel=\"noopener\">North Carolina State University<\/a><\/li>\n<li><a href=\"http:\/\/www.latech.edu\" target=\"www.latech.edu\" rel=\"noopener\">Louisiana Tech University<\/a><\/li>\n<li><a href=\"http:\/\/www.ohio-state.edu\" target=\"www.ohio-state.edu\" rel=\"noopener\">The Ohio State University<\/a><\/li>\n<li><a href=\"http:\/\/www.reading.ac.uk\" target=\"www.reading.ac.uk\" rel=\"noopener\">The University of Reading, UK<\/a><\/li>\n<li><a href=\"http:\/\/www.cray.com\" target=\"www.cray.com\" rel=\"noopener\">Cray Inc.<\/a><\/li>\n<\/ul>\n<h4>Peer-reviewed Journal Publications<\/h4>\n<ol>\n<li>Xubin (Ben) He, Li Ou, Martha J. Kosa, Stephen L. Scott, and Christian Engelmann. <b>A Unified Multiple-Level Cache for High Performance Cluster Storage Systems<\/b>. <i><a href=\"http:\/\/www.inderscience.com\/browse\/index.php?journalcode=ijhpcn\" target=\"www.inderscience.com\/browse\/index.php?journalcode=ijhpcn\" rel=\"noopener\">International Journal of High Performance Computing and Networking (IJHPCN)<\/a><\/i>, volume 5, number 1-2, pages 97-109, November 14, 2007. <a href=\"http:\/\/www.inderscience.com\" target=\"www.inderscience.com\" rel=\"noopener\">Inderscience Publishers, Geneve, Switzerland<\/a>. ISSN 1740-0562. DOI <a href=\"http:\/\/dx.doi.org\/10.1504\/IJHPCN.2007.015768\" target=\"publication\" rel=\"noopener\">10.1504\/IJHPCN.2007.015768<\/a>. <a href=\"javascript:showAbstract('Highly available data storage for high-performance computing is becoming increasingly more critical as high-end computing systems scale up in size and storage systems are developed around network-centered architectures. A promising solution is to harness the collective storage potential of individual workstations much as we harness idle CPU cycles due to the excellent price\/performance ratio and low storage usage of most commodity workstations. For such a storage system, metadata consistency is a key issue assuring storage system availability as well as data reliability. In this paper, we present a decentralized metadata management scheme that improves storage availability without sacrificing performance.');\"><img decoding=\"async\" src=\"images\/txt.gif\" border=\"0\" style=\"border-style:none\" height=\"10pt\" alt=\"Abstract\"><\/a> <a href=\"publications\/he07unified.pdf\" target=\"publication\" rel=\"noopener\"><img decoding=\"async\" src=\"images\/pdf.gif\" border=\"0\" style=\"border-style:none\" height=\"10pt\" alt=\"Publication\"><\/a> <a href=\"?page_id=55#he07unified\"><img decoding=\"async\" src=\"images\/bib.gif\" border=\"0\" style=\"border-style:none\" height=\"10pt\" alt=\"BibTeX Citation\"><\/a><\/li>\n<li>Christian Engelmann, Stephen L. Scott, David E. Bernholdt, Narasimha R. Gottumukkala, Chokchai (Box) Leangsuksun, Jyothish Varma, Chao Wang, Frank Mueller, Aniruddha G. Shet, and Ponnuswamy (Saday) Sadayappan. <b>MOLAR: Adaptive Runtime Support for High-End Computing Operating and Runtime Systems<\/b>. <i><a href=\"http:\/\/www.sigops.org\/osr.html\" target=\"www.sigops.org\/osr.html\" rel=\"noopener\">ACM SIGOPS Operating Systems Review (OSR)<\/a><\/i>, volume 40, number 2, pages 63-72, April 1, 2006. <a href=\"http:\/\/www.acm.org\" target=\"www.acm.org\" rel=\"noopener\">ACM Press, New York, NY, USA<\/a>. ISSN 0163-5980. DOI <a href=\"http:\/\/dx.doi.org\/10.1145\/1131322.1131337\" target=\"publication\" rel=\"noopener\">10.1145\/1131322.1131337<\/a>. <a href=\"javascript:showAbstract('MOLAR is a multi-institutional research effort that concentrates on adaptive, reliable, and efficient operating and runtime system (OS\/R) solutions for ultra-scale, high-end scientific computing on the next generation of supercomputers. This research addresses the challenges outlined in FAST-OS (forum to address scalable technology for runtime and operating systems) and HECRTF (high-end computing revitalization task force) activities by exploring the use of advanced monitoring and adaptation to improve application performance and predictability of system interruptions, and by advancing computer reliability, availability and serviceability (RAS) management systems to work cooperatively with the OS\/R to identify and preemptively resolve system issues. This paper describes recent research of the MOLAR team in advancing RAS for high-end computing OS\/Rs.');\"><img decoding=\"async\" src=\"images\/txt.gif\" border=\"0\" style=\"border-style:none\" height=\"10pt\" alt=\"Abstract\"><\/a> <a href=\"publications\/engelmann06molar.pdf\" target=\"publication\" rel=\"noopener\"><img decoding=\"async\" src=\"images\/pdf.gif\" border=\"0\" style=\"border-style:none\" height=\"10pt\" alt=\"Publication\"><\/a> <a href=\"?page_id=55#engelmann06molar\"><img decoding=\"async\" src=\"images\/bib.gif\" border=\"0\" style=\"border-style:none\" height=\"10pt\" alt=\"BibTeX Citation\"><\/a><\/li>\n<\/ol>\n<h4>Peer-reviewed Conference Publications<\/h4>\n<ol>\n<li>Li Ou, Xubin (Ben) He, Christian Engelmann, and Stephen L. Scott. <b>A Fast Delivery Protocol for Total Order Broadcasting<\/b>. In <i>Proceedings of the <a href=\"http:\/\/www.icccn.org\/icccn07\" target=\"www.icccn.org\/icccn07\" rel=\"noopener\">16th IEEE International Conference on Computer Communications and Networks (ICCCN) 2007<\/a><\/i>, pages 730-734, Honolulu, HI, USA, August 13-16, 2007. <a href=\"http:\/\/www.computer.org\" target=\"www.computer.org\" rel=\"noopener\">IEEE Computer Society, Los Alamitos, CA, USA<\/a>. ISBN 978-1-42441-251-8. ISSN 1095-2055. DOI <a href=\"http:\/\/dx.doi.org\/10.1109\/ICCCN.2007.4317904\" target=\"publication\" rel=\"noopener\">10.1109\/ICCCN.2007.4317904<\/a>. Acceptance rate 29.1% (160\/550). <a href=\"javascript:showAbstract('Sequencer, privilege-based, and communication history algorithms are popular approaches to implement total ordering, where communication history algorithms are most suitable for parallel computing systems, because they provide best performance under heavy work load. Unfortunately, post-transmission delay of communication history algorithms is most apparent when a system is idle. In this paper, we propose a fast delivery protocol to reduce the latency of message ordering. The protocol optimizes the total ordering process by waiting for messages only from a subset of the machines in the group, and by fast acknowledging messages on behalf of other machines. Our test results indicate that the fast delivery protocol is suitable for both idle and heavy load systems, while reducing the latency of message ordering.');\"><img decoding=\"async\" src=\"images\/txt.gif\" border=\"0\" style=\"border-style:none\" height=\"10pt\" alt=\"Abstract\"><\/a> <a href=\"publications\/ou07fast.pdf\" target=\"publication\" rel=\"noopener\"><img decoding=\"async\" src=\"images\/pdf.gif\" border=\"0\" style=\"border-style:none\" height=\"10pt\" alt=\"Publication\"><\/a> <a href=\"publications\/ou07fast.ppt.pdf\" target=\"publication\" rel=\"noopener\"><img decoding=\"async\" src=\"images\/ppt.gif\" border=\"0\" style=\"border-style:none\" height=\"10pt\" alt=\"Presentation\"><\/a> <a href=\"?page_id=55#ou07fast\"><img decoding=\"async\" src=\"images\/bib.gif\" border=\"0\" style=\"border-style:none\" height=\"10pt\" alt=\"BibTeX Citation\"><\/a><\/li>\n<li>Arun B. Nagarajan, Frank Mueller, Christian Engelmann, and Stephen L. Scott. <b>Proactive Fault Tolerance for HPC with Xen Virtualization<\/b>. In <i>Proceedings of the <a href=\"http:\/\/ics07.ac.upc.edu\" target=\"ics07.ac.upc.edu\" rel=\"noopener\">21st ACM International Conference on Supercomputing (ICS) 2007<\/a><\/i>, pages 23-32, Seattle, WA, USA, June 16-20, 2007. <a href=\"http:\/\/www.acm.org\" target=\"www.acm.org\" rel=\"noopener\">ACM Press, New York, NY, USA<\/a>. ISBN 978-1-59593-768-1. DOI <a href=\"http:\/\/dx.doi.org\/10.1145\/1274971.1274978\" target=\"publication\" rel=\"noopener\">10.1145\/1274971.1274978<\/a>. Acceptance rate 23.6% (29\/123). <a href=\"javascript:showAbstract('Large-scale parallel computing is relying increasingly on clusters with thousands of processors. At such large counts of compute nodes, faults are becoming common place. Current techniques to tolerate faults focus on reactive schemes to recover from faults and generally rely on a checkpoint\/restart mechanism. Yet, in today`s systems, node failures can often be anticipated by detecting a deteriorating health status. Instead of a reactive scheme for fault tolerance (FT), we are promoting a proactive one where processes automatically migrate from unhealthy nodes to healthy ones. Our approach relies on operating system virtualization techniques exemplified by but not limited to Xen. This paper contributes an automatic and transparent mechanism for proactive FT for arbitrary MPI applications. It leverages virtualization techniques combined with health monitoring and load-based migration. We exploit Xen`s live migration mechanism for a guest operating system (OS) to migrate an MPI task from a health-deteriorating node to a healthy one without stopping the MPI task during most of the migration. Our proactive FT daemon orchestrates the tasks of health monitoring, load determination and initiation of guest OS migration. Experimental results demonstrate that live migration hides migration costs and limits the overhead to only a few seconds making it an attractive approach to realize FT in HPC systems. Overall, our enhancements make proactive FT a valuable asset for long-running MPI application that is complementary to reactive FT using full checkpoint\/restart schemes since checkpoint frequencies can be reduced as fewer unanticipated failures are encountered. In the context of OS virtualization, we believe that this is the first comprehensive study of proactive fault tolerance where live migration is actually triggered by health monitoring.');\"><img decoding=\"async\" src=\"images\/txt.gif\" border=\"0\" style=\"border-style:none\" height=\"10pt\" alt=\"Abstract\"><\/a> <a href=\"publications\/nagarajan07proactive.pdf\" target=\"publication\" rel=\"noopener\"><img decoding=\"async\" src=\"images\/pdf.gif\" border=\"0\" style=\"border-style:none\" height=\"10pt\" alt=\"Publication\"><\/a> <a href=\"publications\/nagarajan07proactive.ppt.pdf\" target=\"publication\" rel=\"noopener\"><img decoding=\"async\" src=\"images\/ppt.gif\" border=\"0\" style=\"border-style:none\" height=\"10pt\" alt=\"Presentation\"><\/a> <a href=\"?page_id=55#nagarajan07proactive\"><img decoding=\"async\" src=\"images\/bib.gif\" border=\"0\" style=\"border-style:none\" height=\"10pt\" alt=\"BibTeX Citation\"><\/a><\/li>\n<li>Chao Wang, Frank Mueller, Christian Engelmann, and Stephen L. Scott. <b>A Job Pause Service under LAM\/MPI+BLCR for Transparent Fault Tolerance<\/b>. In <i>Proceedings of the <a href=\"http:\/\/www.ipdps.org\/ipdps2007\" target=\"www.ipdps.org\/ipdps2007\" rel=\"noopener\">21st IEEE International Parallel and Distributed Processing Symposium (IPDPS) 2007<\/a><\/i>, pages 1-10, Long Beach, CA, USA, March 26-30, 2007. <a href=\"http:\/\/www.acm.org\" target=\"www.acm.org\" rel=\"noopener\">ACM Press, New York, NY, USA<\/a>. ISBN 978-1-59593-768-1. DOI <a href=\"http:\/\/dx.doi.org\/10.1109\/IPDPS.2007.370307\" target=\"publication\" rel=\"noopener\">10.1109\/IPDPS.2007.370307<\/a>. Acceptance rate 26% (109\/419). <a href=\"javascript:showAbstract('Checkpoint\/restart (C\/R) has become a requirement for long-running jobs in large-scale clusters due to a mean-time-to-failure (MTTF) in the order of hours. After a failure, C\/R mechanisms generally require a complete restart of an MPI job from the last checkpoint. A complete restart, however, is unnecessary since all but one node are typically still alive. Furthermore, a restart may result in lengthy job requeuing even though the original job had not exceeded its time quantum. In this paper, we overcome these shortcomings. Instead of job restart, we have developed a transparent mechanism for job pause within LAM\/MPI+BLCR. This mechanism allows live nodes to remain active and roll back to the last checkpoint while failed nodes are dynamically replaced by spares before resuming from the last checkpoint. Our methodology includes LAM\/MPI enhancements in support of scalable group communication with fluctuating number of nodes, reuse of network connections, transparent coordinated checkpoint scheduling and a BLCR enhancement for job pause. Experiments in a cluster with the NAS Parallel Benchmark suite show that our overhead for job pause is comparable to that of a complete job restart. A minimal overhead of 5.6% is only incurred in case migration takes place while the regular checkpoint overhead remains unchanged. Yet, our approach alleviates the need to reboot the LAM run-time environment, which accounts for considerable overhead resulting in net savings of our scheme in the experiments. Our solution further provides full transparency and automation with the additional benefit of reusing existing resources. Executing continues after failures within the scheduled job, \\em \\textiti.e., the application staging overhead is not incurred again in contrast to a restart. Our scheme offers additional potential for savings through incremental checkpointing and proactive diskless live migration, which we are currently working on.');\"><img decoding=\"async\" src=\"images\/txt.gif\" border=\"0\" style=\"border-style:none\" height=\"10pt\" alt=\"Abstract\"><\/a> <a href=\"publications\/wang07job.pdf\" target=\"publication\" rel=\"noopener\"><img decoding=\"async\" src=\"images\/pdf.gif\" border=\"0\" style=\"border-style:none\" height=\"10pt\" alt=\"Publication\"><\/a> <a href=\"publications\/wang07job.ppt.pdf\" target=\"publication\" rel=\"noopener\"><img decoding=\"async\" src=\"images\/ppt.gif\" border=\"0\" style=\"border-style:none\" height=\"10pt\" alt=\"Presentation\"><\/a> <a href=\"?page_id=55#wang07job\"><img decoding=\"async\" src=\"images\/bib.gif\" border=\"0\" style=\"border-style:none\" height=\"10pt\" alt=\"BibTeX Citation\"><\/a><\/li>\n<\/ol>\n<h4>Peer-reviewed Workshop Publications<\/h4>\n<ol>\n<li>Christian Engelmann, Hong H. Ong, and Stephen L. Scott. <b>Middleware in Modern High Performance Computing System Architectures<\/b>. In <i>Lecture Notes in Computer Science: Proceedings of the <a href=\"http:\/\/www.iccs-meeting.org\/iccs2007\" target=\"www.iccs-meeting.org\/iccs2007\" rel=\"noopener\">7th International Conference on Computational Science (ICCS) 2007<\/a>, Part II: <a href=\"http:\/\/www.gup.uni-linz.ac.at\/cce2007\" target=\"www.gup.uni-linz.ac.at\/cce2007\" rel=\"noopener\">4th Special Session on Collaborative and Cooperative Environments (CCE) 2007<\/a><\/i>, pages 784-791, Beijing, China, May 27-30, 2007. <a href=\"http:\/\/www.springer.com\" target=\"www.springer.com\" rel=\"noopener\">Springer Verlag, Berlin, Germany<\/a>. ISBN 3-5407-2585-5. ISSN 0302-9743. DOI <a href=\"http:\/\/dx.doi.org\/10.1007\/978-3-540-72586-2_111\" target=\"publication\" rel=\"noopener\">10.1007\/978-3-540-72586-2_111<\/a>. <a href=\"javascript:showAbstract('A recent trend in modern high performance computing (HPC) system architectures employs lean compute nodes running a lightweight operating system (OS). Certain parts of the OS a well as other system software services are moved to service nodes in order to increase performance and scalability. This paper examines the impact of this HPC system architecture trend on HPC middleware software solutions, which traditionally equip HPC systems with advanced features, such as parallel and distributed programming models, appropriate system resource management mechanisms, remote application steering and user interaction techniques. Since the approach of keeping the compute node software stack small and simple is orthogonal to the middleware concept of adding missing OS features between OS and application, the role and architecture of middleware in modern HPC systems needs to be revisited. The result is a paradigm shift in HPC middleware design, where single middleware services are moved to service nodes, while runtime environments (RTEs) continue to reside on compute nodes.');\"><img decoding=\"async\" src=\"images\/txt.gif\" border=\"0\" style=\"border-style:none\" height=\"10pt\" alt=\"Abstract\"><\/a> <a href=\"publications\/engelmann07middleware.pdf\" target=\"publication\" rel=\"noopener\"><img decoding=\"async\" src=\"images\/pdf.gif\" border=\"0\" style=\"border-style:none\" height=\"10pt\" alt=\"Publication\"><\/a> <a href=\"publications\/engelmann07middleware.ppt.pdf\" target=\"publication\" rel=\"noopener\"><img decoding=\"async\" src=\"images\/ppt.gif\" border=\"0\" style=\"border-style:none\" height=\"10pt\" alt=\"Presentation\"><\/a> <a href=\"?page_id=55#engelmann07middleware\"><img decoding=\"async\" src=\"images\/bib.gif\" border=\"0\" style=\"border-style:none\" height=\"10pt\" alt=\"BibTeX Citation\"><\/a><\/li>\n<\/ol>\n<h4>Talks and Lectures<\/h4>\n<ol>\n<li>Christian Engelmann. <b>System Resilience Research at ORNL in the Context of HPC<\/b>. Invited talk at the <a href=\"http:\/\/www.inria.fr\/inria\/organigramme\/fiche_ur-ren.fr.html\" target=\"www.inria.fr\/inria\/organigramme\/fiche_ur-ren.fr.html\" rel=\"noopener\">Institut National de Recherche en Informatique et en Automatique (INRIA)<\/a>, Rennes, France, May 15, 2009. <a href=\"javascript:showAbstract('The continuing growth in high performance computing (HPC) system scale poses a challenge for system software and scientific applications with respect to reliability, availability and serviceability (RAS). With only very few exceptions, the availability of recently installed systems has been lower in comparison to the same deployment phase of their predecessors. As a result, sites lower allowable job run times in order to force applications to store intermediate results (checkpoints) as insurance against lost computation time. However, checkpoints themselves waste valuable computation time and resources. In contrast to the experienced loss of availability, the demand for continuous availability has risen dramatically with the trend towards capability computing, which drives the race for scientific discovery by running applications on the fastest machines available while desiring significant amounts of time (weeks and months) without interruption. These machines must be able to run in the event of frequent interrupts in such a manner that the capability is not severely degraded. Thus, research and development of scalable RAS technologies is paramount to the success of future extreme-scale systems. This talk summarizes our accomplishments in the area of high-level RAS for HPC, such as developed concepts and implemented proof-of-concept prototypes.');\"><img decoding=\"async\" src=\"images\/txt.gif\" border=\"0\" style=\"border-style:none\" height=\"10pt\" alt=\"Abstract\"><\/a> <a href=\"publications\/engelmann09system.ppt.pdf\" target=\"publication\" rel=\"noopener\"><img decoding=\"async\" src=\"images\/ppt.gif\" border=\"0\" style=\"border-style:none\" height=\"10pt\" alt=\"Presentation\"><\/a> <a href=\"?page_id=55#engelmann09system\"><img decoding=\"async\" src=\"images\/bib.gif\" border=\"0\" style=\"border-style:none\" height=\"10pt\" alt=\"BibTeX Citation\"><\/a><\/li>\n<li>Christian Engelmann. <b>High-Performance Computing Research at Oak Ridge National Laboratory<\/b>. Invited talk at the Reading Annual Computational Science  Workshop, Reading, United Kingdom, December 8, 2008. <a href=\"javascript:showAbstract('Oak Ridge National Laboratory (ORNL) is the largest energy laboratory in the United States. Its National Center for Computational Sciences (NCCS) provides the most powerful computing resources in the world for open scientific research. Jaguar, a Cray XT5 system at NCCS, is the second HPC system to exceed 1 PFlop\/s (10^15 Floating Point Operations Per Second), and the fastest open science supercomputer in the world. It recently ranked #2 in the Top 500 List of Supercomputer Sites with a maximal LINPACK benchmark performance of 1.059 PFlop\/s and a theoretical peak performance of 1.3814 PFlop\/s. Annually, 80 percent of Jaguar\u2019s resources are allocated through the U.S Department of Energy\u2019s Innovative and Novel Computational Impact on Theory and Experiment (INCITE) program, a competitively selected, peer reviewed process open to researchers from universities, industry, government and non-profit organizations. These allocations address some of the most challenging scientific problems in areas such as climate modeling, renewable energy, materials science, fusion and combustion. In conjunction with NCCS, the Computer Science and Mathematics Division at ORNL performs basic and applied research in HPC, mathematics, and intelligent systems. This talk gives a summary of the HPC research performed at ORNL. It provides details about the Jaguar peta-scale computing resource, an overview of the computational science research carried out using ORNL\u2019s computing resources, and a description of various computer science efforts targeting solutions for next-generation HPC systems.');\"><img decoding=\"async\" src=\"images\/txt.gif\" border=\"0\" style=\"border-style:none\" height=\"10pt\" alt=\"Abstract\"><\/a> <a href=\"publications\/engelmann08high.ppt.pdf\" target=\"publication\" rel=\"noopener\"><img decoding=\"async\" src=\"images\/ppt.gif\" border=\"0\" style=\"border-style:none\" height=\"10pt\" alt=\"Presentation\"><\/a> <a href=\"?page_id=55#engelmann08high\"><img decoding=\"async\" src=\"images\/bib.gif\" border=\"0\" style=\"border-style:none\" height=\"10pt\" alt=\"BibTeX Citation\"><\/a><\/li>\n<li>Christian Engelmann. <b>Modular Redundancy in HPC Systems: Why, Where, When and How?<\/b>. Invited talk at the 1st HPC Resiliency Summit: Workshop on Resiliency for Petascale HPC 2008, in conjunction with the <a href=\"http:\/\/www.lanl.gov\/conferences\/lacss\/2008\" target=\"www.lanl.gov\/conferences\/lacss\/2008\" rel=\"noopener\">1st Los Alamos Computer Science Symposium (LACSS) 2008<\/a>, Santa Fe, NM, USA, October 15, 2008. <a href=\"javascript:showAbstract('The continuing growth in high-performance computing (HPC) system scale poses a challenge for system software and scientific applications with respect to reliability, availability and serviceability (RAS). With only very few exceptions, the availability of recently installed systems has been lower in comparison to the same deployment phase of their predecessors. As a result, sites lower allowable job run times in order to force applications to store intermediate results (checkpoints) as insurance against lost computation time. However, checkpoints themselves waste valuable computation time and resources. In contrast to the experienced loss of availability, the demand for continuous availability has risen dramatically with the trend towards capability computing, which drives the race for scientific discovery by running applications on the fastest machines available while desiring significant amounts of time (weeks and months) without interruption. These machines must be able to run in the event of frequent interrupts in such a manner that the capability is not severely degraded. Thus, research and development of scalable RAS technologies is paramount to the success of future extreme-scale systems. This talk summarizes our past accomplishments, ongoing work, and future plans in the area of high-level RAS for HPC.');\"><img decoding=\"async\" src=\"images\/txt.gif\" border=\"0\" style=\"border-style:none\" height=\"10pt\" alt=\"Abstract\"><\/a> <a href=\"publications\/engelmann08modular.ppt.pdf\" target=\"publication\" rel=\"noopener\"><img decoding=\"async\" src=\"images\/ppt.gif\" border=\"0\" style=\"border-style:none\" height=\"10pt\" alt=\"Presentation\"><\/a> <a href=\"?page_id=55#engelmann08modular\"><img decoding=\"async\" src=\"images\/bib.gif\" border=\"0\" style=\"border-style:none\" height=\"10pt\" alt=\"BibTeX Citation\"><\/a><\/li>\n<li>Christian Engelmann. <b>Resiliency for High-Performance Computing<\/b>. Invited talk at the <a href=\"http:\/\/acet.rdg.ac.uk\/events\/details\/cancun.php\" target=\"acet.rdg.ac.uk\/events\/details\/cancun.php\" rel=\"noopener\">2nd Collaborative and Grid Computing Technologies Workshop (CGCTW) 2008<\/a>, Cancun, Mexico, April 10-12, 2008. <a href=\"javascript:showAbstract('In order to address anticipated high failure rates, resiliency characteristics have become an urgent priority for next-generation high-performance computing (HPC) systems. One major source of concern are non-recoverable soft errors, i.e., bit flips in memory, cache, registers, and logic. The probability of such errors not only grows with system size, but also with increasing architectural vulnerability caused by employing accelerators and by shrinking nanometer technology. Reactive fault tolerance technologies, such as checkpoint\/restart, are unable to handle high failure rates due to associated overheads, while proactive resiliency technologies, such as preemptive migration, simply fail as random soft errors can&amp;#39;t be predicted. This talk proposes a new, bold direction in resiliency for HPC as it targets resiliency for next-generation extreme-scale HPC systems at the system software level through computational redundancy strategies, i.e., dual- and triple-modular redundancy.');\"><img decoding=\"async\" src=\"images\/txt.gif\" border=\"0\" style=\"border-style:none\" height=\"10pt\" alt=\"Abstract\"><\/a> <a href=\"publications\/engelmann08resiliency.ppt.pdf\" target=\"publication\" rel=\"noopener\"><img decoding=\"async\" src=\"images\/ppt.gif\" border=\"0\" style=\"border-style:none\" height=\"10pt\" alt=\"Presentation\"><\/a> <a href=\"?page_id=55#engelmann08resiliency\"><img decoding=\"async\" src=\"images\/bib.gif\" border=\"0\" style=\"border-style:none\" height=\"10pt\" alt=\"BibTeX Citation\"><\/a><\/li>\n<li>Christian Engelmann. <b>Advanced Fault Tolerance Solutions for High Performance Computing<\/b>. Seminar at the <a href=\"http:\/\/www.laas.fr\" target=\"www.laas.fr\" rel=\"noopener\">Laboratoire d&#39;Analyse et d&#8217;Architecture des Syst&eacute;mes<\/a>, <a href=\"http:\/\/www.cnrs.fr\" target=\"www.cnrs.fr\" rel=\"noopener\">Centre National de la Recherche Scientifique<\/a>, Toulouse, France, February 11, 2008. <a href=\"javascript:showAbstract('The continuing growth in high performance computing (HPC) system scale poses a challenge for system software and scientific applications with respect to reliability, availability and serviceability (RAS). With only very few exceptions, the availability of recently installed systems has been lower in comparison to the same deployment phase of their predecessors. As a result, sites lower allowable job run times in order to force applications to store intermediate results (checkpoints) as insurance against lost computation time. However, checkpoints themselves waste valuable computation time and resources. In contrast to the experienced loss of availability, the demand for continuous availability has risen dramatically with the trend towards capability computing, which drives the race for scientific discovery by running applications on the fastest machines available while desiring significant amounts of time (weeks and months) without interruption. These machines must be able to run in the event of frequent interrupts in such a manner that the capability is not severely degraded. Thus, research and development of scalable RAS technologies is paramount to the success of future extreme-scale systems. This talk summarizes our accomplishments in the area of high-level RAS for HPC, such as developed concepts and implemented proof-of-concept prototypes, and describes existing limitations, such as performance issues, which need to be dealt with for production-type deployment.');\"><img decoding=\"async\" src=\"images\/txt.gif\" border=\"0\" style=\"border-style:none\" height=\"10pt\" alt=\"Abstract\"><\/a> <a href=\"publications\/engelmann08advanced.ppt.pdf\" target=\"publication\" rel=\"noopener\"><img decoding=\"async\" src=\"images\/ppt.gif\" border=\"0\" style=\"border-style:none\" height=\"10pt\" alt=\"Presentation\"><\/a> <a href=\"?page_id=55#engelmann08advanced\"><img decoding=\"async\" src=\"images\/bib.gif\" border=\"0\" style=\"border-style:none\" height=\"10pt\" alt=\"BibTeX Citation\"><\/a><\/li>\n<li>Christian Engelmann. <b>Advanced Fault Tolerance Solutions for High Performance Computing<\/b>. Invited talk at the <a href=\"http:\/\/www.thaigrid.or.th\/wttc2007\" target=\"www.thaigrid.or.th\/wttc2007\" rel=\"noopener\">Workshop on Trends, Technologies and Collaborative Opportunities in High Performance and Grid Computing (WTTC) 2007<\/a>, Khon Kean, Thailand, June 8, 2007. <a href=\"javascript:showAbstract('The continuing growth in high performance computing (HPC) system scale poses a challenge for system software and scientific applications with respect to reliability, availability and serviceability (RAS). With only very few exceptions, the availability of recently installed systems has been lower in comparison to the same deployment phase of their predecessors. As a result, sites lower allowable job run times in order to force applications to store intermediate results (checkpoints) as insurance against lost computation time. However, checkpoints themselves waste valuable computation time and resources. In contrast to the experienced loss of availability, the demand for continuous availability has risen dramatically with the trend towards capability computing, which drives the race for scientific discovery by running applications on the fastest machines available while desiring significant amounts of time (weeks and months) without interruption. These machines must be able to run in the event of frequent interrupts in such a manner that the capability is not severely degraded. Thus, research and development of scalable RAS technologies is paramount to the success of future extreme-scale systems. This talk summarizes our accomplishments in the area of high-level RAS for HPC, such as developed concepts and implemented proof-of-concept prototypes, and describes existing limitations, such as performance issues, which need to be dealt with for production-type deployment.');\"><img decoding=\"async\" src=\"images\/txt.gif\" border=\"0\" style=\"border-style:none\" height=\"10pt\" alt=\"Abstract\"><\/a> <a href=\"publications\/engelmann07advanced2.ppt.pdf\" target=\"publication\" rel=\"noopener\"><img decoding=\"async\" src=\"images\/ppt.gif\" border=\"0\" style=\"border-style:none\" height=\"10pt\" alt=\"Presentation\"><\/a> <a href=\"?page_id=55#engelmann07advanced2\"><img decoding=\"async\" src=\"images\/bib.gif\" border=\"0\" style=\"border-style:none\" height=\"10pt\" alt=\"BibTeX Citation\"><\/a><\/li>\n<li>Christian Engelmann. <b>Advanced Fault Tolerance Solutions for High Performance Computing<\/b>. Invited talk at the <a href=\"http:\/\/www.thaigrid.or.th\/wttc2007\" target=\"www.thaigrid.or.th\/wttc2007\" rel=\"noopener\">Workshop on Trends, Technologies and Collaborative Opportunities in High Performance and Grid Computing (WTTC) 2007<\/a>, Bangkok, Thailand, June 4-5, 2007. <a href=\"javascript:showAbstract('The continuing growth in high performance computing (HPC) system scale poses a challenge for system software and scientific applications with respect to reliability, availability and serviceability (RAS). With only very few exceptions, the availability of recently installed systems has been lower in comparison to the same deployment phase of their predecessors. As a result, sites lower allowable job run times in order to force applications to store intermediate results (checkpoints) as insurance against lost computation time. However, checkpoints themselves waste valuable computation time and resources. In contrast to the experienced loss of availability, the demand for continuous availability has risen dramatically with the trend towards capability computing, which drives the race for scientific discovery by running applications on the fastest machines available while desiring significant amounts of time (weeks and months) without interruption. These machines must be able to run in the event of frequent interrupts in such a manner that the capability is not severely degraded. Thus, research and development of scalable RAS technologies is paramount to the success of future extreme-scale systems. This talk summarizes our accomplishments in the area of high-level RAS for HPC, such as developed concepts and implemented proof-of-concept prototypes, and describes existing limitations, such as performance issues, which need to be dealt with for production-type deployment.');\"><img decoding=\"async\" src=\"images\/txt.gif\" border=\"0\" style=\"border-style:none\" height=\"10pt\" alt=\"Abstract\"><\/a> <a href=\"publications\/engelmann07advanced.ppt.pdf\" target=\"publication\" rel=\"noopener\"><img decoding=\"async\" src=\"images\/ppt.gif\" border=\"0\" style=\"border-style:none\" height=\"10pt\" alt=\"Presentation\"><\/a> <a href=\"?page_id=55#engelmann07advanced\"><img decoding=\"async\" src=\"images\/bib.gif\" border=\"0\" style=\"border-style:none\" height=\"10pt\" alt=\"BibTeX Citation\"><\/a><\/li>\n<\/ol>\n<h4>Theses<\/h4>\n<ol>\n<li>Christian Engelmann. <b>Symmetric Active\/Active High Availability for High-Performance Computing System Services<\/b>. PhD thesis, <a href=\"http:\/\/www.cs.reading.ac.uk\" target=\"www.cs.reading.ac.uk\" rel=\"noopener\">Department of Computer Science<\/a>, <a href=\"http:\/\/www.reading.ac.uk\" target=\"www.reading.ac.uk\" rel=\"noopener\">University of Reading<\/a>, UK, December 8, 2008. Thesis research performed at Oak Ridge National Laboratory. Advisor: Prof. Vassil N. Alexandrov (University of Reading). <a href=\"javascript:showAbstract('In order to address anticipated high failure rates, reliability, availability and serviceability have become an urgent priority for next-generation high-performance computing (HPC) systems. This thesis aims to pave the way for highly available HPC systems by focusing on their most critical components and by reinforcing them with appropriate high availability solutions. Service components, such as head and service nodes, are the Achilles heel of a HPC system. A failure typically results in a complete system-wide outage. This thesis targets efficient software state replication mechanisms for service component redundancy to achieve high availability as well as high performance. Its methodology relies on defining a modern theoretical foundation for providing service-level high availability, identifying availability deficiencies of HPC systems, and comparing various service-level high availability methods. This thesis showcases several developed proof-of-concept prototypes providing high availability for services running on HPC head and service nodes using the symmetric active\/active replication method, i.e., state-machine replication, to complement prior work in this area using active\/standby and asymmetric active\/active configurations. Presented contributions include a generic taxonomy for service high availability, an insight into availability deficiencies of HPC systems, and a unified definition of service-level high availability methods. Further contributions encompass a fully functional symmetric active\/active high availability prototype for a HPC job and resource management service that does not require modification of service, a fully functional symmetric active\/active high availability prototype for a HPC parallel file system metadata service that offers high performance, and two preliminary prototypes for a transparent symmetric active\/active replication software framework for client-service and dependent service scenarios that hide the replication infrastructure from clients and services. Assuming a mean-time to failure of 5,000 hours for a head or service node, all presented prototypes improve service availability from 99.285% to 99.995% in a two-node system, and to 99.99996% with three nodes.');\"><img decoding=\"async\" src=\"images\/txt.gif\" border=\"0\" style=\"border-style:none\" height=\"10pt\" alt=\"Abstract\"><\/a> <a href=\"publications\/engelmann08symmetric3.pdf\" target=\"publication\" rel=\"noopener\"><img decoding=\"async\" src=\"images\/pdf.gif\" border=\"0\" style=\"border-style:none\" height=\"10pt\" alt=\"Publication\"><\/a> <a href=\"publications\/engelmann08symmetric3.ppt.pdf\" target=\"publication\" rel=\"noopener\"><img decoding=\"async\" src=\"images\/ppt.gif\" border=\"0\" style=\"border-style:none\" height=\"10pt\" alt=\"Presentation\"><\/a> <a href=\"?page_id=55#engelmann08symmetric3\"><img decoding=\"async\" src=\"images\/bib.gif\" border=\"0\" style=\"border-style:none\" height=\"10pt\" alt=\"BibTeX Citation\"><\/a><\/li>\n<\/ol>\n<p><em><small>Symbols: <img decoding=\"async\" style=\"border-style: none;\" src=\"images\/txt.gif\" border=\"0\" alt=\"Abstract\" height=\"10pt\"> Abstract, <img decoding=\"async\" style=\"border-style: none;\" src=\"images\/pdf.gif\" border=\"0\" alt=\"Publication\" height=\"10pt\"> Publication, <img decoding=\"async\" style=\"border-style: none;\" src=\"images\/ppt.gif\" border=\"0\" alt=\"Presentation\" height=\"10pt\"> Presentation, <img decoding=\"async\" style=\"border-style: none;\" src=\"images\/bib.gif\" border=\"0\" alt=\"BibTeX Citation\" height=\"10pt\"> BibTeX Citation<\/small><\/em><\/p>\n<p><script language=\"JavaScript\">\nfunction showAbstract (text) {\n  var width  = 400;\n  var height = 400;\n  var left   = (screen.width  - width ) \/ 2;\n  var top    = (screen.height - height) \/ 2;\n  var win    = window.open('',\n                           'Abstract',\n                           'width='  + width  + ', ' + \n                           'height=' + height + ', ' +\n                           'left='   + left   + ', ' +\n                           'top='    + top    + ', ' +\n                           'toolbar=no, '     +\n                           'location=no, '    +\n                           'directories=no, ' +\n                           'status=no, '      +\n                           'menubar=no, '     +\n                           'copyhistory=no, ' +\n                           'scrollbars=yes, ' +\n                           'resizable=yes')\n  win.document.write(text);\n  win.document.close();\n}\n<\/script><\/p>\n","protected":false},"excerpt":{"rendered":"<p>This project is a multi-institution research effort that targets adaptive, reliable, and efficient operating and runtime system solutions for ultra-scale high-end scientific computing on the next generation of supercomputers. It addresses the challenges outlined by the U.S. Department of Energy (DOE) Forum to Address Scalable Technology for Runtime and Operating Systems (FAST-OS) and the U.S.&hellip;&nbsp;<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":145,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"neve_meta_sidebar":"","neve_meta_container":"","neve_meta_enable_content_width":"off","neve_meta_content_width":100,"neve_meta_title_alignment":"","neve_meta_author_avatar":"","neve_post_elements_order":"","neve_meta_disable_header":"","neve_meta_disable_footer":"","neve_meta_disable_title":"","footnotes":""},"class_list":["post-359","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.christian-engelmann.info\/index.php?rest_route=\/wp\/v2\/pages\/359","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.christian-engelmann.info\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.christian-engelmann.info\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.christian-engelmann.info\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.christian-engelmann.info\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=359"}],"version-history":[{"count":9,"href":"https:\/\/www.christian-engelmann.info\/index.php?rest_route=\/wp\/v2\/pages\/359\/revisions"}],"predecessor-version":[{"id":498,"href":"https:\/\/www.christian-engelmann.info\/index.php?rest_route=\/wp\/v2\/pages\/359\/revisions\/498"}],"up":[{"embeddable":true,"href":"https:\/\/www.christian-engelmann.info\/index.php?rest_route=\/wp\/v2\/pages\/145"}],"wp:attachment":[{"href":"https:\/\/www.christian-engelmann.info\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=359"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}