The document discusses scheduling MapReduce jobs in HPC clusters. It presents a MapReduce Job Adaptor that allows MapReduce jobs to run alongside regular HPC jobs in a shared HPC cluster managed by a resource management system. The adaptor estimates completion times for MapReduce jobs to minimize average turnaround times and better utilize unused cluster resources. An evaluation of the adaptor in a simulated cluster shows it reduces turnaround times for MapReduce-only and mixed workloads compared to a naive approach.