CASSANDRA-10241 introduced debug logging turned on by default to act as a verbose system.log and help troubleshoot production issues.
One of the consequence was to severely affect read performance in 2.2 as contributors weren't all up to speed on how to use logging levels (
As DEBUG level has a very specific meaning in dev, it is confusing to use it for always on verbose logging and should probably not be used this way in Cassandra.
Options so far are :
- Bring back common loggings to INFO level (compactions, flushes, etc...) and disable debug logging by default
- Use files named as verbose-system.log instead of debug.log and use a custom logging level instead of DEBUG for verbose tracing, that would be enabled by default. Debug logging would still exist and be disabled by default in the root logger (not just filtered at the appender level).