Abstract: Many researchers around the world are working hard to improve cloud-based services focusing on server-side and communication aspects. This is especially true for services which demand high processing power and storage space on their server’s infrastructure, such as live video streaming on the web and video on demand. However, issues on client-side applications are often neglected or studied to a lower extent. In this context, this paper evaluates the occurrence of software aging in a web browser plug-in for video streaming. The case study is carried out by using an automated workload that simulates the user behavior accessing videos on YouTube. Time series were used to predict the resources utilization ahead of time, enabling the prevention of performance degradation and unexpected crashes. Finally, the prediction-based strategy is compared to the time-based strategy, showing the impact of both on system’s availability.

Abstract: High Performance Computing (HPC) aggregates computing power in order to solve large and complex problems in different knowledge areas. Nowadays, HPC users can utilize virtualized infrastructures as a low-cost alternative to deploy their applications. However, virtualization brings some challenges for HPC, specially in regard to overhead caused by hypervisors. In this work, our main goal is to analyze the performance of two hypervisors (KVM and VirtualBox) under HPC activities, considering full virtualization, and paravirtualization approaches. We used the HPC Challenge Benchmark (HPCC) to evaluate processor, RAM, inter-process communication and network communication performance. Our results show KVM in paravirtualization mode has a similar performance of a native cluster.

On April 08, 2015: I participated in the WMoDCS 2015.1 with the presentation PocketStack: Uma Plataforma de Alta Disponibilidade para Nuvens Privadas, at Recife-PE, Brazil.

Resumo: Computação de Alto Desempenho (CAD) é um tema atual e que demanda por uma infraestrutura adequada para seu ensino em cursos de graduação. Entretanto, nem todas as instituições de ensino têm recursos financeiros para proporcionar estruturas computacionais dedicadas exclusivamente ao ensino de tópicos de CAD. Neste trabalho, é apresentada uma infraestrutura para o auxílio no ensino de CAD construída com a utilização de computadores destinados ao descarte. O uso de tais computadores destinados originalmente ao descarte colaborou também na transmissão de princípios de TI Verde.