mesos/spark — pull request #438 by JoshRosen (2013-02-01 19:20:43+00:00)
Title: Do not launch JavaGateways on workers (SPARK-674).

This fixes [SPARK-674](https://spark-project.atlassian.net/browse/SPARK-674), which describes how Py4J JavaGateway processes were accidentally being launched on remote worker machines. This had a huge performance overhead.

After fixing this, the unit tests run 3-4x faster on my machine.