[IMPALA-6521] Hidden flags should show up in /varz and should be printed in the logs during startup

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: Impala 2.12.0
• Fix Version/s: Impala 3.2.0
• Component/s: Backend
• Labels: ramp-up supportability
• Target Version: Product Backlog
• Epic Color: ghx-label-5
• Assignee: Fredy Wijaya
• Reporter: Lars Volker
• Created: 14/Feb/18 00:19
• Updated: 04/Jan/19 21:52
• Resolved: 04/Jan/19 16:58

Description

Flags can be defined as hidden, which hides them from the help output. However, they are also hidden from /varz and from the logs during startup. This seems contradictory; we should make sure that we log it if a user enables a hidden flag / feature.

We could even consider adding a warning to the log and to the main debug page if hidden / experimental features are enabled.