logback.xml file

logback.xml configuration file can optionally set logging levels for the logs written to system.log and debug.log. The logging levels can also be set using nodetool setlogginglevels.

Options

appender name="<appender_choice>"…​</appender>

SYSTEMLOG, DEBUGLOG, ASYNCDEBUGLOG, and STDOUT. SYSTEMLOG ensures that WARN and ERROR message are written synchronously to the specified file. DEBUGLOG and ASYNCDEBUGLOG ensure that DEBUG messages are written either synchronously or asynchronously, respectively, to the specified file. STDOUT writes all messages to the console in a human-readable format. Example:

<file> <filename> </file>

Specify the filename for a log. Example: ${cassandra.logdir}/system.log

<level> <log_level> </level>

ALL, TRACE, DEBUG, INFO, WARN, ERROR, OFF. TRACE creates the most verbose log, ERROR the least. Default: INFO Example: INFO

<rollingPolicy class="<rolling_policy_choice>" <fileNamePattern><pattern_info></fileNamePattern> …​ </rollingPolicy>

Specify the policy for rolling logs over to an archive. Example:

<fileNamePattern> <pattern_info> </fileNamePattern>

Specify the pattern information for rolling over the log to archive. Part of the rolling policy. Example: ${cassandra.logdir}/system.log.%d{yyyy-MM-dd}.%i.zip

<maxFileSize> <size> </maxFileSize>

Specify the maximum file size to trigger rolling a log. Part of the rolling policy. Example: 50MB

<maxHistory> <number_of_days> </maxHistory>

Specify the maximum history in days to trigger rolling a log. Part of the rolling policy. Example: 7

<encoder> <pattern>…​</pattern> </encoder>

Specify the format of the message. Part of the rolling policy. Example: 7 Example: %-5level [%thread] %date{ISO8601} %F:%L - %msg%n

Logging to Cassandra virtual table

system_views.system_log table. This is achieved by appender implemented in class VirtualTableAppender which is called CQLLOG in the default configration. When the appender is commented out, no system logs are written to the virtual table. system_log table is limited on its size. By default, it can hold at most 50 000 log messages, it can never hold more than 100 000 log messages. cassandra.virtual.logs.max.rows which takes an integer as value. truncate query for system_views.system_log if you want to wipe out all the logs in virtual table to e.g. save some memory. WARN level so this table holds only important logging messages as each message will occupy memory. The appender to virtual table is commented out by default so logging to virtual table is not active.

logback.xml

<configuration scan="true" scanPeriod="60 seconds">  <jmxConfigurator />  <!-- No shutdown hook; we run it ourselves in StorageService after shutdown -->  <!-- 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>INFO</level>    </filter>    <file>${cassandra.logdir}/system.log</file>    <rollingPolicy class="ch.qos.logback.core.rolling.SizeAndTimeBasedRollingPolicy">      <!-- rollover daily -->      <fileNamePattern>${cassandra.logdir}/system.log.%d{yyyy-MM-dd}.%i.zip</fileNamePattern>      <!-- each file should be at most 50MB, keep 7 days worth of history, but at most 5GB -->      <maxFileSize>50MB</maxFileSize>      <maxHistory>7</maxHistory>      <totalSizeCap>5GB</totalSizeCap>    </rollingPolicy>    <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>${cassandra.logdir}/debug.log</file>    <rollingPolicy class="ch.qos.logback.core.rolling.SizeAndTimeBasedRollingPolicy">      <!-- rollover daily -->      <fileNamePattern>${cassandra.logdir}/debug.log.%d{yyyy-MM-dd}.%i.zip</fileNamePattern>      <!-- each file should be at most 50MB, keep 7 days worth of history, but at most 5GB -->      <maxFileSize>50MB</maxFileSize>      <maxHistory>7</maxHistory>      <totalSizeCap>5GB</totalSizeCap>    </rollingPolicy>    <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 [%thread] %date{ISO8601} %F:%L - %msg%n</pattern>    </encoder>  </appender>  <!-- Uncomment bellow and corresponding appender-ref to activate logback metrics  <appender name="LogbackMetrics" class="com.codahale.metrics.logback.InstrumentedAppender" />   -->  <!-- Uncomment below configuration and corresponding appender-ref to activate  logging into system_views.system_logs virtual table. -->  <!-- <appender name="CQLLOG" class="org.apache.cassandra.utils.logging.VirtualTableAppender">    <filter class="ch.qos.logback.classic.filter.ThresholdFilter">      <level>WARN</level>    </filter>  </appender> -->  <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" />    -->    <!--    <appender-ref ref="CQLLOG"/>    -->  </root>  <logger name="org.apache.cassandra" level="DEBUG"/></configuration>