Case found by stereshchenko.
- Install Ambari 2.4.2
- Setup ambari-agent to run as non-root user with its own group
- Set umask=027 for ambari-agent's user
- Deploy cluster with Spark2, including Thrift Server
- Upgrade to Ambari 2.5.0
- Start Spark2 Thrift Server
Result: Spark2 Thrift Server stops soon after being started even after the upgrade