How to avoid double logging with logback? [duplicate]

Question

In my application, I would like to log some messages coming from my own code in a specific manner compared to all other messages being logged. However I am not sure how can I avoid them also being automatically logged to the logack root logger.

Using this configuration below, I would like to use code like follows (scala) so that I can log certain messages only to that logger.

val logger: Logger = LoggerFactory.getLogger("data-logger")

However in the configuration below, these messages get logged twice, i.e. they are logged also by the root logger. How can I avoid that? must I quite artificially use a different logging level to accomplish something like that with logback?

<configuration>

  <appender name="FILE" class="ch.qos.logback.core.rolling.RollingFileAppender">
    <file>logs/activity.log</file>
    <rollingPolicy class="ch.qos.logback.core.rolling.FixedWindowRollingPolicy">
      <fileNamePattern>activity.%i.log.zip</fileNamePattern>
      <minIndex>1</minIndex>
      <maxIndex>10</maxIndex>
    </rollingPolicy>
    <triggeringPolicy class="ch.qos.logback.core.rolling.SizeBasedTriggeringPolicy">
      <maxFileSize>10MB</maxFileSize>
    </triggeringPolicy>
    <encoder>
      <pattern>%msg%n</pattern>
    </encoder>
  </appender>

  <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
    <encoder>
      <pattern>%msg%n</pattern>
    </encoder>
  </appender>

  <appender name="ASYNC" class="ch.qos.logback.classic.AsyncAppender">
    <!-- use discarding threshold of zero to avoid ignoring INFO level messages see docs -->
    <discardingThreshold>0</discardingThreshold>
      <appender-ref ref="FILE" />
  </appender>

  <root level="info">
    <appender-ref ref="STDOUT" />
    <appender-ref ref="ASYNC" />
  </root>

  <logger name="data-logger" level="info">
    <appender-ref ref="STDOUT" />
    <appender-ref ref="ASYNC" />
  </logger>

</configuration>

Answer 1

Loggers are hierarchical, and any message sent to a logger will be sent to all its ancestors by default. You can disable this behavior by setting additivity=false. E.g.:

<logger name="data-logger" level="info" additivity="false">