The YARN CLI logs command line option -logFiles was changed to -log_files in 2.9 and later releases. This change was made as part of
Verizon Media is in the process of moving from Hadoop-2.8 to Hadoop-2.10, and while testing integration with Spark, we ran into this issue. We are concerned that we will run into more cases of this as we roll out to production, and rather than break user scripts, we'd prefer to add -logFiles as an alias of -log_files. If both are provided, -logFiles will be ignored.