MapReduce is a programming paradigm for parallel processing that is increasingly being used for data-intensive applications in
cloud computing environments. An understanding of the characteristics of workloads running in MapReduce environments benefits
both the service providers in the cloud and users: the service provider can use this knowledge to make better scheduling decisions,
while the user can learn what aspects of their jobs impact performance. This paper analyzes 10-months of MapReduce logs from
the M45 supercomputing cluster which Yahoo! made freely available to select universities for systems research. We characterized
resource utilization patterns, job patterns, and sources of failures. We use an instance-based learning technique that exploits
temporal locality to predict job completion times from historical data and identify potential performance problems in our dataset.