[CASSANDRA-17904] Consider to not warn about deprecated properties in logs when the value is not deprecated

• Type: Improvement
• Status: Resolved
• Priority: Low
• Resolution: Fixed
• Fix Version/s: 4.1-beta1, 4.1
• Component/s: Local/Config
• Change Category: Operability
• Complexity: Low Hanging Fruit
• Platform: All

Source Control Link

https://github.com/apache/cassandra/commit/4c85c6a4030d7d613230cd4b2204c42f941fd552

Test and Documentation Plan

The same patch was added for both 4.1 and trunk.

I tested manually to see that the warnings are not presented anymore on startup. I can push sanity check CI pre-commit when smiklosovic or any other committer reviewer approves the change. 

• Assignee: Ekaterina Dimitrova
• Reporter: Stefan Miklosovic

Authors

Ekaterina Dimitrova

Reviewers

Stefan Miklosovic

• Created: 18/Sep/22 07:17
• Updated: 05/Oct/22 22:22
• Resolved: 19/Sep/22 22:38

Description

When there is an initialisation of database descriptor for tools, for example via "Util.initDatabaseDescriptor()", it will eventually buble up to "YamlConfigurationLoader.check" where this is logged:

if (!deprecationWarnings.isEmpty())
logger.warn("{} parameters have been deprecated. They have new names and/or value format; For more information, please refer to NEWS.txt", deprecationWarnings);

For example, I saw this log:

WARN  09:07:42,486 [key_cache_save_period, counter_cache_save_period, row_cache_save_period] parameters have been deprecated. They have new names and/or value format; For more information, please refer to NEWS.txt

The "problems" I see are two:
1) it pollutes the console for tool commands, when a tool needs to initialise DD, at the very beginning of the output.
2) When you look closely, for example at key_cache_save_period, by default, in cassandra.yaml, it has value "4h". My question is: why is it necessary to mark that as deprecated when the value is already in new format? In other words, I would log that warning only in case that the expected value of a property is not in the new format. But when it already is, why do we need to inform a user about that?

I think it would require to take some extra care for cases like these in YamlConfigurationLoader.getProperty to not add deprecated properties if their value is already new.