Bilgisayar Mühendisliği Bölümü Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.11779/1940
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Conference Object Citation - Scopus: 4Openmp and Posix Threads Implementation of Jerasure 2.0(IEEE, 2017) Arslan, Şuayb Şefik; Arslan, Şefik Şuayb; Landman, Joseph; Goker, Turguy; 02.02. Department of Computer Engineering; 02. Faculty of Engineering; 01. MEF UniversityIn shared memory multiprocessor architectures, threads can be used to implement parallelism. POSIX threads (pthreads) is a low-level bare-bones programming interface for working with threads. Therefore, we have extremely fine-grained control over thread management (create/join/etc), mutexes, and so on. On the other hand, openMP, as a shared-memory standard, is much higher level and portable interface which makes it easier to use multi-threading capability and obtain satisfactory performance improvements. Since pthreads is more flexible, it helps programmers gain more control on performance optimizations. Jerasure 2.0 erasure coding library has encoding/decoding engines which comprise independent "for" loop iterations and hence possess huge potential for multi-threaded processing. In this short paper, we investigate multi-threaded implementations of encoder/decoder pair of Jerasure 2.0 using two different technologies: OpenMP and pthreads. We constrain our changes to a minimum possible and compare the pure encoding/decoding performance with respect to each other as well as against that of the original single-threaded version by running them on two different server systems.Conference Object Citation - WoS: 2Citation - Scopus: 5Mojette Transform Based Ldpc Erasure Correction Codes for Distributed Storage Systems(IEEE, 2017) Arslan, Şuayb Şefik; Arslan, Şefik Şuayb; Normand, Nicolas; Parrein, Benoit; 02.02. Department of Computer Engineering; 02. Faculty of Engineering; 01. MEF UniversityMojette Transform (MT) based erasure correction coding possesses extremely efficient encoding/decoding algorithms and demonstrate promising burst erasure recovery performance. MT codes are based on discrete geometry and provide redundancy through creating projections. Projections are made of smaller data structures called bins and are generated from a two dimensional convex-shaped data. For exact data recovery, only a subset of projections are needed by the decoder. We realize that the discrete geometry definition of MT erasure codes corresponds to creating structured/deterministic generator matrices. In this study, we show an alternative Low Density Parity Check (LDPC) code construction methodology through investigating parity check matrices of MT codes which shows sparseness as the blocklength of the code gets large. In a distributed storage setting, we also quantify the repair bandwidth and show that this novel interpretation can be used to facilitate bin-level local repairs.Conference Object Citation - WoS: 2Citation - Scopus: 2Implementation of Multi-Threaded Erasure Coding Under Multi-Processing Environments(IEEE, 2016) Arslan, Şefik Şuayb; 02.02. Department of Computer Engineering; 02. Faculty of Engineering; 01. MEF UniversityGalois alan aritmetiği depolama ve iletişim cihazlarını veri kayıplarına karşı korumak için Reed-Solomon silme kodlarının temelini oluşturmaktadır. Galois alan aritmeti^ginin en güncel uygulamaları hızlı Galois alan hesaplamaları yapmamıza imkan sağlayan Intel’in SIMD eklerinde olduğu gibi 128-bitlik işlemci vektör talimatlarına dayanmaktadır. Buna rağmen, bu uygulamalar çoklu–dizin ve çoklu–süreçli ortamlara göre optimize edilmemiştir. Diğer taraftan, sunucuların çoklu istekleri eş zamanlı olarak yerine getirmesi ve donanımın sağladığı tüm paralelliği kodlama yükünü etkili yürütmek için kullanması arzu edilmektedir. Bu makale silme kodlarının çoklu-dizin işlemcilerle çoklu–süreçli ortamlarda nasıl kullanılaca^gının detaylarını sunmakta ve tek dizinli uygulamalara göre emtia mikro işlemciler ve Jerasure 2.0 yazılım kütüphanesini kullanarak önemli ölçüde performans artışının olabileceğini göstermektedir.