We have seen several instances where Spark 1.6.1 over time
continues to consume more and more resources.
The change Ibf244cbfc00a90ada66f492b473719c25fa17fd2 was not
enough alone to curb this growth, but the new version of Spark
has shown better behavior.
Related changes will also need to be done in any installer,
such as Ansible.
Change-Id: Ib6b1220cf0186def115846c8cf71684bb2d6e8c7