Dynamic load balancing in parallel processing on non-homogeneous clusters

This paper analyzes the dynamic and static balancing of non-homogenous cluster architectures, simultaneously analyzing the theoretical parallel Speedup as well as the Speedup experimentally obtained. Three interconnected clusters have been used in which the machines within each cluster have homogeneous processors although different among clusters. Thus, the set can be seen as a 25-processor heterogeneous cluster or as a multi-cluster scheme with subsets of homogeneous processors. A classical application (Parallel N-Queens) with a parallel solution algorithm, where processing predominates upon communication, has been chosen so as to go deep in the load balancing aspects (dynamic or static) without distortion of results caused by communication overhead. At the same time, three forms of load distribution in the processors (Direct Static, Predictive Static and Dynamic by Demand) have been studied, analyzing in each case parallel Speedup and load unbalancing regarding problem size and the processors used.Facultad de Informátic

Parallelization of the N-queens problem : Load unbalance analysis.

The paper presents an analysis of three parallelization structures of the N-queens problem, taking into account N processors. The focus has been set on investigating the adaptation of the architecture structure to the proposed algorithm type, so as to study the load unbalance in each case, for which two different metrics have been established. The experimental results and the efficient implementation of the algorithms are discussed together with the related current research lines.Eje: Procesamiento distribuido y paralelo (PDP)Red de Universidades con Carreras en Informática (RedUNCI

A Study of Hardware Performance Counters Selection for Cross Architectural GPU Power Modeling

In the exascale race where huge corporations are spending billions of dollars on designing highly efficient heterogeneous supercomputers, the real need to reduce power envelopes forces current technologies to face crucial challenges as well as it demands the scientific community to evaluate and optimize the performance-power ratio. While energy consumption continues to climb up, the viability of these massive systems becomes a growing concern. In this context, the relevance of specific power-related research works turns into a priority. So we here develop an exhaustive step-by-step process for selecting a comprehensive set of hardware performance counters to serve as an input in an eventual GPU cross-architectural power consumption model. Our experiments show a high power-performance correlation between shared GPU events. Also, we present a set of events that delivers exclusive performance information in order to predict accurately GPU power fluctuations.XX Workshop Procesamiento Distribuido y Paralelo.Red de Universidades con Carreras en Informátic

Parallelization of image similarity analysis

The algorithmical architecture and structure is presented for the parallelization of image similarity analysis, based on obtaining multiple digital signatures for each image, in which each "signature" is composed by the most representative coefficients of the wavelet transform of the corresponding image area. In the present paper, image representation by wavelet transform coefficients is analyzed, as well as the convenience/necessity of using multiple coefficients for the study of similarity of images which may have transferred components, with change of sizes, color or texture. The complexity of the involved computation justifies parallelization, and the suggested solution constitutes a combination of a multiprocessors "pipelining", being each of them an homogeneous parallel architecture which obtains signature coefficients (wavelet). Partial reusability of computations for successive signatures makes these architectures pipelining compulsory.Facultad de Informátic

A Study of Hardware Performance Counters Selection for Cross Architectural GPU Power Modeling

In the exascale race where huge corporations are spending billions of dollars on designing highly efficient heterogeneous supercomputers, the real need to reduce power envelopes forces current technologies to face crucial challenges as well as it demands the scientific community to evaluate and optimize the performance-power ratio. While energy consumption continues to climb up, the viability of these massive systems becomes a growing concern. In this context, the relevance of specific power-related research works turns into a priority. So we here develop an exhaustive step-by-step process for selecting a comprehensive set of hardware performance counters to serve as an input in an eventual GPU cross-architectural power consumption model. Our experiments show a high power-performance correlation between shared GPU events. Also, we present a set of events that delivers exclusive performance information in order to predict accurately GPU power fluctuations.XX Workshop Procesamiento Distribuido y Paralelo.Red de Universidades con Carreras en Informátic

A Study of Hardware Performance Counters Selection for Cross Architectural GPU Power Modeling

In the exascale race where huge corporations are spending billions of dollars on designing highly efficient heterogeneous supercomputers, the real need to reduce power envelopes forces current technologies to face crucial challenges as well as it demands the scientific community to evaluate and optimize the performance-power ratio. While energy consumption continues to climb up, the viability of these massive systems becomes a growing concern. In this context, the relevance of specific power-related research works turns into a priority. So we here develop an exhaustive step-by-step process for selecting a comprehensive set of hardware performance counters to serve as an input in an eventual GPU cross-architectural power consumption model. Our experiments show a high power-performance correlation between shared GPU events. Also, we present a set of events that delivers exclusive performance information in order to predict accurately GPU power fluctuations.XX Workshop Procesamiento Distribuido y Paralelo.Red de Universidades con Carreras en Informátic

Pattern recognition in medical images using neural networks

The proposal of this research line is the search for alternatives to the resolution of complex problems where human knowledge should be apprehended in a general fashion. In particular, the activities developed so far can be included in the area of Medical Diagnosis, even though similar applications in other fields are not discarded. In general, one of the greatest problems of medical diagnosis is the subjectivity of the specialist. The experience of the professional greatly affects the final diagnosis. This is due to the fact that the result does not depend on a systematized solution, but on the interpretation of the patient´s answer. The solution to this kind of problems can be found in the area of Adaptive Pattern Recognition, where the solution rests on the easiness with which the systems adapts to the information available, in this case coming from the patient. In this sense, neural networks are extremely useful, since they are not only capable of learning with the aid of an expert, but they can also make generalizations based on the information from the input data, thus showing relations that are a priori of a complex nature.Facultad de Informátic

Short Papers of the 8th Conference on Cloud Computing Conference, Big Data & Emerging Topics (JCC-BD&ET 2020)

Compilación de los short papers presentados en las 8vas Jornadas de Cloud Computing, Big Data & Emerging Topics (JCC-BD&ET2020), llevadas a cabo en modalidad virtual durante septiembre de 2020 y organizadas por el Instituto de Investigación en Informática LIDI (III-LIDI) y la Secretaría de Posgrado de la Facultad de Informática de la UNLP en colaboración con universidades de Argentina y del exterior.Facultad de Informátic

Parallel Pipelines for DNA Sequence Alignment on a Cluster of Multicores: A Comparison of Communication Models

HPC (high perfomance computing) based on clusters of multicores is one of the main research lines in parallel programming. It is important to study the impact of programming paradigms of shared memory, message passing or a combination of both on these architectures in order to efficiently exploit the power of these architectures. The Smith-Waterman algorithm is used as study case for the local alignment of DNA sequences, which allows establishing the similarity degree between two sequences. In this paper, the Smith-Waterman algorithm is parallelized by means of a pipeline scheme due to the data dependencies that are inherent to the problem, using the various communication/synchronization models mentioned above and then carrying out a comparative analysis. Finally, experimental results are presented, as well as future research lines.Facultad de Informátic

DNA sequence alignment: hybrid parallel programming on a multicore cluster

DNA sequence alignment is one of the most important operations of computational biology. In 1981, Smith and Waterman developed a method for sequences local alignment. Due to its computational power and memory requirements, various heuristics have been developed to reduce execution time at the expense of a loss of accuracy in the result. This is why heuristics do not ensure that the best alignment is found. For this reason, it is interesting to study how to apply the computer power of different parallel platforms to speed up the sequence alignment process without losing result accuracy. In this article, a new parallelization strategy (HI-M) of Smith-Waterman algorithm on a multi-core cluster is presented, configuring a pipeline with a hybrid communication model. Additionally, a performance analysis is carried out and compared with two previously presented parallel solutions. Finally, experimental results are presented, as well as future research lines.Facultad de Informátic