apache/spark — pull request #3776 by XuTingjun (2014-12-23 08:10:55+00:00)
Title: [YARN] Delete confusion configurations

First, I think put master/work config into yarn mode is confusion.
Second, it will add the config twice. For example, if SPARK_WORKER_INSTANCES is null and spark.executor.instances isn't null, it will put "--executor-memory" into extraArgs twice.