logback manually call rollover

Question

Using logback I would like to start new log every time an async job starts so I need to call rollover manually. But when I try to get appender I get null instead. Below is my config:

<configuration scan="true">
    <timestamp key="time" datePattern="yyyy-MM-dd_HH_mm"/>
    <logger name="com.my.com.pany" level="DEBUG">
        <appender name="TEST" class="ch.qos.logback.core.rolling.RollingFileAppender">
            <file>logs/log_TEST_${time}.log</file>
            <triggeringPolicy
                    class="com.my.com.pany.myapp.logging.ManualRollingPolicy">
            </triggeringPolicy>
            <append>true</append>
            <encoder>
                <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n</pattern>
            </encoder>
        </appender>
    </logger>
</configuration>

I call rollover like this:

  ch.qos.logback.classic.Logger logF = (ch.qos.logback.classic.Logger) LoggerFactory.getLogger("com.my.com.pany");
        RollingFileAppender<ILoggingEvent> appender = (RollingFileAppender<ILoggingEvent>) logF.getAppender("test");
        appender.rollover();

I extended TimeBasedRollingPolicy<E> so that my log will start when i trigger async job:

@NoAutoStart
public class ManualRollingPolicy<E> extends TimeBasedRollingPolicy<E> {
}

Could somone help me with this issue? EDIT: Upon some further investigation I can see that LogF has appenderList of size 1 which has my custom RollingPolicy properly set. However name property of this appender is set to null and I think that is the reason why I can't get it by name.

Answer 1

So I got a pretty neat workaround which I think someone may find helpful. You can use SiftingAppender. "As its name implies, a SiftingAppender can be used to separate (or sift) logging according to a given runtime attribute"

So you configure your appender to take some unique parameter, in my case date of batch job start:

<appender name="FULL" class="ch.qos.logback.classic.sift.SiftingAppender">
        <discriminator>
            <key>id</key>
            <defaultValue>000000</defaultValue>
        </discriminator>

        <sift>
            <appender name="FULL-${id}" class="ch.qos.logback.core.FileAppender">
                <file>logs/log_${id}.log</file>
                <append>false</append>
                <layout class="ch.qos.logback.classic.PatternLayout">
                    <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n</pattern>
                </layout>
            </appender>
        </sift>
    </appender>

And then you manually call: MDC.put("id",id); in order to start new log and when you are done with this paticular log file you just log a FINALIZE_SESSION_MARKER constant: logger.info(ClassicConstants.FINALIZE_SESSION_MARKER). In my opinion it is flexible enough that it answers the question of manuall rollover.