Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The popularization of multi-core architectures and cloud services has allowed users access to high performance computing infrastructures. However, programming for these systems might be cumbersome due to challenges involving system failures, load balancing, and task scheduling. Aiming at solving these problems, we previously introduced SPITS, a programming model and reference architecture for executing bag-of-task applications. In this work, we discuss how this programming model allowed us to design and implement PY-PITS, a simple and effective open source runtime system that is scalable, tolerates faults and allows dynamic provisioning of resources during computation of tasks. We also discuss how PY-PITS can be used to improve utilization of multi-user computational clusters equipped with queues to submit jobs and propose a performance model to aid users to understand when the performance of PY-PITS scales with the number of Workers.712PetrobrasCAPESFAPESPCNPqCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)28th IEEE International Symposium on Computer Architecture and High Performance Computing (SBAC-PAD)OCT 26-28, 2016Los Angeles, CA