Reduce diagnostic log verbosity ​

Diagnostic verbosity comes from the logger section in the configuration the server actually loads. The documented default level is debug, while the installation example explicitly uses information. Check the file selected by --config-file before editing a similarly named file elsewhere.

Choose the detail needed for normal operation:

<logger>
    <level>information</level>
    <log>server.log</log>
    <errorlog>server.err.log</errorlog>
    <size>10M</size>
    <count>3</count>
</logger>

Restart to apply the change. Relative log paths are resolved from the configuration directory, so a different --db path does not move the logs. Keep positive rotation sizes and the archive count appropriate for your retention needs. Unknown logger fields or invalid values cause configuration errors rather than silently taking effect.

Reducing file verbosity does not disable structured request history. Its separate log_queries and duration settings determine what appears in system.query_log. Prefer those structured events when investigating a specific query ID, duration or exception; use diagnostic files for the additional context needed by that investigation.

See logger and file paths and query logging settings.