Minor Description
We use a different poll interval for the MRExecutor depending on whether or not we're running in local mode, and we determine whether or not we're running in local mode based on the value of the mapreduce.jobtracker.address property in the configuration. However, a more reliable way to do this is by checking the mapreduce.framework.name, esp. for yarn-based jobs that will not have a meaningful value for the jobtracker property.