Yarn timeline recovery not enabled error upgrading via ambari Using the automated upgrade, when I try to upgrade I get:

“YARN Timeline state preserving restart should be enabled
Reason: YARN should have state preserving restart enabled for the Timeline server. The yarn-site.xml property yarn.timeline-service.recovery.enabled should be set to true”

However, using Ambari, whenever I go to change the setting in yarn-site.xml it gets me to create a new configuration group and changes it there. I have moved all of the servers into that config group but the check still fails.

How do I modify the default yarn-site.xml?
Alternatively, does anyone know the actual script (or how to find it) that is kicked off when the automated upgrade is invoked?
Run the following from the ambari server's shell:

/var/lib/ambari-server/resources/scripts/configs.sh set mace gamma yarn-site "yarn.timeline-service.recovery.enabled" "true"

Where mace is the ambari server's host name and gamma is the cluster name