In one of my current projects we’re developing a web application which also has a couple of dozen batch jobs that perform all sort of tasks at particular times. These jobs produce quite a bit of logging output when they’re run, which is important to see what has happened during a job exactly. What we noticed however, is that the batch logging would make it hard to quickly spot the other logging performed by the application while also running a batch job. In addition to that, it wasn’t always clear in the context of what job a log statement was issued.
To address these issues I came up with a simple solution based on Logback Filters, which I’ll describe in this blog.
Logback Appenders
We’re using Logback as a logging framework. Logback defines the concept of appenders: appenders are responsible for handling the actual log messages emitted by the loggers in the application by writing them to the console, to a file, to a socket, etc.
Many applications define one or more appenders and them simply list them all as part of their root logger section in the logback.xml configuration file:
<configuration scan="true">
<appender name="LOGSTASH" class="net.logstash.logback.appender.LogstashTcpSocketAppender">
<destination>logstash-server</destination>
<encoder class="net.logstash.logback.encoder.LogstashEncoder"/>
</appender>
<appender name="FILE" class="ch.qos.logback.core.rolling.RollingFileAppender">
<file>log/server.log</file>
<rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
<fileNamePattern>log/server.%d{yyyy-MM-dd}.log</fileNamePattern>
<maxHistory>30</maxHistory>
</rollingPolicy>
<encoder>
<pattern>%d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] %mdc %-5level %logger{36} - %msg%n</pattern>
</encoder>
</appender>
<root level="info">
<appender-ref ref="LOGSTASH"/>
<appender-ref ref="FILE"/>
</root>
</configuration>
This setup will send all log messages to both of the configured appenders. Read the rest of this entry »
