Right now, it is impossible to disable explore service on CM or Ambari clusters.
The following error will be encountered:
This will also happen on other clusters (4.3.0 onwards) if explore is disabled and there is a cdap-site.xml configuration with the prefix "explore.executor.twill.". This is due to the changes in https://github.com/caskdata/cdap/pull/9351.
Ambari and CM clusters have such configurations by default, since https://issues.cask.co/browse/CDAP-12767.
A fix would be to ignore the "explore.executor.twill." configurations when explore is disabled.
Should fix the MasterTwillApplication.getRunnableConfigPrefixes method instead to not to include explore in the returned Map
...only when explore is disabled.
Not a priority for 5.1