logback.xml

    <!--
     Licensed to the Apache Software Foundation (ASF) under one
     or more contributor license agreements.  See the NOTICE file
     distributed with this work for additional information
     regarding copyright ownership.  The ASF licenses this file
     to you under the Apache License, Version 2.0 (the
     "License"); you may not use this file except in compliance
     with the License.  You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

     Unless required by applicable law or agreed to in writing,
     software distributed under the License is distributed on an
     "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
     KIND, either express or implied.  See the License for the
     specific language governing permissions and limitations
     under the License.
    -->

    <!--
    In order to disable debug.log, comment-out the ASYNCDEBUGLOG
    appender reference in the root level section below.
    -->

    <configuration scan="true">
      <jmxConfigurator />
      <shutdownHook class="ch.qos.logback.core.hook.DelayingShutdownHook"/>

      <!-- SYSTEMLOG rolling file appender to system.log (INFO level) -->

      <appender name="SYSTEMLOG" class="ch.qos.logback.core.rolling.RollingFileAppender">
        <filter class="ch.qos.logback.classic.filter.ThresholdFilter">
          <level>DEBUG</level>
        </filter>
        <file>${cassandra.logdir}/system.log</file>
        <rollingPolicy class="ch.qos.logback.core.rolling.FixedWindowRollingPolicy">
          <fileNamePattern>${cassandra.logdir}/system.log.%i.zip</fileNamePattern>
          <minIndex>1</minIndex>
          <maxIndex>20</maxIndex>
        </rollingPolicy>
        <triggeringPolicy class="ch.qos.logback.core.rolling.SizeBasedTriggeringPolicy">
          <maxFileSize>20MB</maxFileSize>
        </triggeringPolicy>
        <encoder>
          <pattern>%-5level [%thread] %date{ISO8601} %F:%L - %msg%n</pattern>
        </encoder>
      </appender>

      <!-- DEBUGLOG rolling file appender to debug.log (all levels) -->

      <appender name="DEBUGLOG" class="ch.qos.logback.core.rolling.RollingFileAppender">
        <file>${cassandra.logdir}/debug.log</file>
        <rollingPolicy class="ch.qos.logback.core.rolling.FixedWindowRollingPolicy">
          <fileNamePattern>${cassandra.logdir}/debug.log.%i.zip</fileNamePattern>
          <minIndex>1</minIndex>
          <maxIndex>20</maxIndex>
        </rollingPolicy>
        <triggeringPolicy class="ch.qos.logback.core.rolling.SizeBasedTriggeringPolicy">
          <maxFileSize>20MB</maxFileSize>
        </triggeringPolicy>
        <encoder>
          <pattern>%-5level [%thread] %date{ISO8601} %F:%L - %msg%n</pattern>
        </encoder>
      </appender>

      <!-- ASYNCLOG assynchronous appender to debug.log (all levels) -->

      <appender name="ASYNCDEBUGLOG" class="ch.qos.logback.classic.AsyncAppender">
        <queueSize>1024</queueSize>
        <discardingThreshold>0</discardingThreshold>
        <includeCallerData>true</includeCallerData>
        <appender-ref ref="DEBUGLOG" />
      </appender>

      <!-- STDOUT console appender to stdout (INFO level) -->

      <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
        <filter class="ch.qos.logback.classic.filter.ThresholdFilter">
          <level>INFO</level>
        </filter>
        <encoder>
          <pattern>%-5level %date{HH:mm:ss,SSS} %msg%n</pattern>
        </encoder>
      </appender>

      <!-- Uncomment bellow and corresponding appender-ref to activate logback metrics
      <appender name="LogbackMetrics" class="com.codahale.metrics.logback.InstrumentedAppender" />
       -->

      <root level="INFO">
        <appender-ref ref="SYSTEMLOG" />
        <appender-ref ref="STDOUT" />
        <!-- <appender-ref ref="ASYNCDEBUGLOG" /> --> <!-- Comment this line to disable debug.log -->
        <!--
        <appender-ref ref="LogbackMetrics" />
        -->
      </root>

      <logger name="org.apache.cassandra" level="DEBUG"/>
      <logger name="com.thinkaurelius.thrift" level="ERROR"/>
    </configuration>