Do I need to reload yarn when I edit yarn-site.xml?
Yes, you have.
You can also verify this by using Ambari. One edit in the yarn-site.xml file triggers some services to be restarted. YARN is one of them
Yes, you have.
You can also verify this by using Ambari. One edit in the yarn-site.xml file triggers some services to be restarted. YARN is one of them