Do You Feel the Lag of Your Hadoop?

The configuration of a Hadoop cluster is significantly important to its performance, because an improper configuration can greatly deteriorate the job execution performance. Unfortunately, systematic guidelines on how to configure a Hadoop cluster are still missing. In this paper, we undertake an empirical study on key operations and mechanisms of Hadoop job execution, including the task assignment strategy and speculative execution. Based on the experiments, we provide suggestions on the system configuration, particularly on the matching between the hardware resource partitioning scheme and the job splitting granularity.