During the stack upgrade from HDP 2.6 -> HDP 3.x, the list of changes Ambari wants to make to each service is very difficult to interpret. Below is an example of the config changes Ambari recommends when attempting to upgrade fresh-install HDP2.6.2 cluster.
Here's an example of how these configs look like when the user presses the "Open" button:
Note the highlighting is not intentional - it is automatically done by the browser (chrome) due to the special characters in the configs.
A small step to improve the user experience would be to add a column that shows which service each config applies.