1. Add the broker plugin to activemq.xml
  <plugins>
    ..
    <loggingBrokerPlugin logAll="true" logConnectionEvents="true"/>
    ..
  </plugins>
  
2. Add the following settings to etc/org.ops4j.pax.logging.cfg

log4j2.logger.activemqtrace.name = org.apache.activemq.broker.util.LoggingBrokerPlugin
log4j2.logger.activemqtrace.level = INFO
log4j2.logger.activemqtrace.additivity = false
log4j2.logger.activemqtrace.appenderRef.ConsoleRollingFile.ref = ActiveMQTraceRollingFile
log4j2.appender.activemqtrace.type = RollingRandomAccessFile
log4j2.appender.activemqtrace.name = ActiveMQTraceRollingFile
log4j2.appender.activemqtrace.fileName = ${karaf.data}/log/activemq-trace.log
log4j2.appender.activemqtrace.filePattern = ${karaf.data}/log/activemq-trace.log.%i
log4j2.appender.activemqtrace.append = true
log4j2.appender.activemqtrace.layout.type = PatternLayout
log4j2.appender.activemqtrace.layout.pattern = ${log4j2.pattern}
log4j2.appender.activemqtrace.policies.type = Policies
log4j2.appender.activemqtrace.policies.size.type = SizeBasedTriggeringPolicy
log4j2.appender.activemqtrace.policies.size.size = 8MB
log4j2.appender.activemqtrace.strategy.type = DefaultRolloverStrategy
log4j2.appender.activemqtrace.strategy.max = 16