apache/spark — pull request #1454 by lirui-intel (2014-07-17 02:40:55+00:00)
Title: SPARK-2277: clear host->rack info properly

Hi @mridulm, I just think of this issue of [#1212](https://github.com/apache/spark/pull/1212): I added FakeRackUtil to hold the host -> rack mapping. It should be cleaned up after use so that it won't mess up with test cases others may add later.
Really sorry about this.