2,144 research outputs found

    In-memory application-level checkpoint-based migration for MPI programs

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    This is a post-peer-review, pre-copyedit version of an article published in Journal of Supercomputing. The final authenticated version is available online at: https://doi.org/10.1007/s11227-014-1120-2[Abstract] Process migration provides many benefits for parallel environments including dynamic load balancing, data access locality or fault tolerance. This paper describes an in-memory application-level checkpoint-based migration solution for MPI codes that uses the Hierarchical Data Format 5 (HDF5) to write the checkpoint files. The main features of the proposed solution are transparency for the user, achieved through the use of CPPC (ComPiler for Portable Checkpointing); portability, as the application-level approach makes the solution adequate for any MPI implementation and operating system, and the use of the HDF5 file format enables the restart on different architectures; and high performance, by saving the checkpoint files to memory instead of to disk through the use of the HDF5 in-memory files. Experimental results prove that the in-memory approach reduces significantly the I/O cost of the migration process.Ministerio de Ciencia e InnovaciĂłn; TIN2010-16735Galicia. ConsellerĂ­a de EconomĂ­a e Industria; 10PXIB105180P

    Failure Avoidance in MPI Applications Using an Application-Level Approach

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    [Abstract] Execution times of large-scale computational science and engineering parallel applications are usually longer than the mean-time-between-failures. For this reason, hardware failures must be tolerated by the applications to ensure that not all computation done is lost on machine failures. Checkpointing and rollback recovery is one of the most popular techniques to provide fault tolerance support to parallel applications. However, when a failure occurs, most checkpointing mechanisms require a complete restart of the parallel application from the last checkpoint. New advances in the prediction of hardware failures have led to the development of proactive process migration approaches, where tasks are migrated in a preventive way when node failures are anticipated, avoiding the restart of the whole application. The work presented in this paper extends an application-level checkpointing framework to proactively migrate message passing interface (MPI) processes when impending failures are notified, without having to restart the entire application. The main features of the proposed solution are: low overhead in failure-free executions, avoiding the checkpoint dumping associated to rolling back strategies; low overhead at migration time, by means of the design of a light and asynchronous protocol to achieve a consistent global state; transparency for the user, thanks to the use of a compiler tool and a runtime library and portability, as it is not locked into a particular architecture, operating system or MPI implementation.Ministerio de Ciencia e InnovaciĂłn; TIN2010-16735Galicia. ConsellerĂ­a de EconomĂ­a e Industria; 10PXIB105180P

    Reducing the overhead of an MPI application-level migration approach

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    [Abstract] Process migration provides many benefits for parallel environments including dynamic load balance, data access locality, or fault tolerance. This work proposes a solution that reduces the memory and I/O overhead in an application-level checkpoint-based migration approach. The proposal splits the checkpoint files in order to overlap the writing of the state in the terminating processes with the read and restarting operation in the newly spawned processes. It has been tested using the MPI NAS Parallel Benchmarks, showing encouraging results, both in terms of memory consumption and I/O migration times.Ministerio de EconomĂ­a y Competitividad; TIN2013-42148-PGalicia. ConsellerĂ­a de Cultura, EducaciĂłn e OrdenaciĂłn Universitaria; GRC2013/05

    Mexican Women’s Parliament: Is it the way to reach gender equity

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    One of the most important decisions taken by the Mexican Assembly is to approve the annual budget of the country. Beijing Agreements in 1995 change the perception in the parliament which was merely for men. So, the few Mexican women in the parliament from the different parties organized the “Women’s Parliament” to reach gender equity not only in the different parties but in political, economic and social life. This year the women deputies and senators divided the country in five regions and had meetings outside of the central parliament office. at San Lázaro in Mexico City. These meetings tried to include the rich diversity demands from the different states, municipals and NGOs that participate during three weeks between February and March 2005. At the end of the regional meetings all the agreements were approved in the federal parliament. After Beijing Agreements + 10 not only the government but politicians are aware of improving empowerment women which has been a goal in a “machista” and traditional societ

    Human–Robot Interaction and Sexbots: A Systematic Literature Review

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    At present, sexual robots have become a new paradigm of social robots. In this paper, we developed a systematic literature review about sexual robots (sexbots). To do this, we used the Scopus and WoS databases to answer different research questions regarding the design, interaction, and gender and ethical approaches from 1980 until 2020. In our review, we found a male bias in this discipline, and in recent years, articles have shown that user opinion has become more relevant. Some insights and recommendations on gender and ethics in designing sexual robots were also made

    Extending an Application-Level Checkpointing Tool to Provide Fault Tolerance Support to OpenMP Applications

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    [Abstract] Despite the increasing popularity of shared-memory systems, there is a lack of tools for providing fault tolerance support to shared-memory applications. CPPC (ComPiler for Portable Checkpointing) is an application-level checkpointing tool focused on the insertion of fault tolerance into long-running MPI applications. This paper presents an extension to CPPC to allow the checkpointing of OpenMP applications. The proposed solution maintains the main characteristics of CPPC: portability and reduced checkpoint file size. The performance of the proposal is evaluated using the OpenMP NAS Parallel Benchmarks showing that most of the applications present small checkpoint overheads.Ministerio de EconomĂ­a y Competitividad; TIN2013-42148-

    Analysis of Performance-impacting Factors on Checkpointing Frameworks: The CPPC Case Study

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    This is a post-peer-review, pre-copyedit version of an article published in The Computer Journal. The final authenticated version is available online at: https://doi.org/10.1093/comjnl/bxr018[Abstract] This paper focuses on the performance evaluation of Compiler for Portable Checkpointing (CPPC), a tool for the checkpointing of parallel message-passing applications. Its performance and the factors that impact it are transparently and rigorously identified and assessed. The tests were performed on a public supercomputing infrastructure, using a large number of very different applications and showing excellent results in terms of performance and effort required for integration into user codes. Statistical analysis techniques have been used to better approximate the performance of the tool. Quantitative and qualitative comparisons with other rollback-recovery approaches to fault tolerance are also included. All these data and comparisons are then discussed in an effort to extract meaningful conclusions about the state-of-the-art and future research trends in the rollback-recovery field.Minsiterio de Ciencia e InnovaciĂłn; TIN2010-1673

    A Heuristic Approach for the Automatic Insertion of Checkpoints in Message-Passing Codes

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    [Abstract] Checkpointing tools may be typically implemented at two different abstraction levels: at the system level or at the application level. The latter has become a more popular alternative due to its flexibility and the possibility of operating in different environments. However, application-level checkpointing tools often require the user to manually insert checkpoints in order to ensure that certain requirements are met (e.g. forcing checkpoints to be taken at the user code and not inside kernel routines). The approach presented in this work is twofold. First, a spatial coordination protocol for checkpointing parallel SPMD applications is proposed, based on forcing checkpoints to be taken at the same places in the application code by all processes. Thus, global consistency is achieved without adding any new runtime communications or piggybacked data, and without the need to use specific fault-tolerant message-passing implementations. Second, the paper also introduces a compilation technique for the automatic insertion of checkpoints using the spatial coordination protocol, based on a static analysis of communications and a heuristic analysis of computational load. These analyses can also be used to achieve automatic checkpoint insertion in approaches based on classical protocols, such as uncoordinated checkpointing or distributed snapshots.Ministerio de Ciencia e InnovaciĂłn; TIN-2007-67537-C03-0

    Improving Scalability of Application-Level Checkpoint-Recovery by Reducing Checkpoint Sizes

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    This is a post-peer-review, pre-copyedit version of an article published in New Generation Computing. The final authenticated version is available online at: https://doi.org/10.1007/s00354-013-0302-4[Abstract] The execution times of large-scale parallel applications on nowadays multi/many-core systems are usually longer than the mean time between failures. Therefore, parallel applications must tolerate hardware failures to ensure that not all computation done is lost on machine failures. Checkpointing and rollback recovery is one of the most popular techniques to implement fault-tolerant applications. However, checkpointing parallel applications is expensive in terms of computing time, network utilization and storage resources. Thus, current checkpoint-recovery techniques should minimize these costs in order to be useful for large scale systems. In this paper three different and complementary techniques to reduce the size of the checkpoints generated by application-level checkpointing are proposed and implemented. Detailed experimental results obtained on a multicore cluster show the effectiveness of the proposed methods to reduce checkpointing cost.Ministerio de Ciencia e InnovaciĂłn; TIN2010-16735Galicia. ConsellerĂ­a de EconomĂ­a e Industria; 10PXIB105180P
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