log4net RollingFileAppender configuration

The RollingFileAppender builds on the FileAppender and has the same options as that appender.

The following example shows how to configure the RollingFileAppender to write to the file log.txt. The file written to will always be called log.txt because the StaticLogFileName param is specified. The file will be rolled based on a size constraint (RollingStyle). Up to 10 (MaxSizeRollBackups) old files of 100 KB each (MaximumFileSize) will be kept. These rolled files will be named: log.txt.1, log.txt.2, log.txt.3, etc…

<appender name="RollingFileAppender" type="log4net.Appender.RollingFileAppender">
    <file value="log.txt" />
    <appendToFile value="true" />
    <rollingStyle value="Size" />
    <maxSizeRollBackups value="10" />
    <maximumFileSize value="100KB" />
    <staticLogFileName value="true" />
    <layout type="log4net.Layout.PatternLayout">
        <conversionPattern value="%date [%thread] %-5level %logger [%property{NDC}] - %message%newline" />
    </layout>
</appender>

This example show how to configure the RollingFileAppender to roll log files on a date period. This example will roll the log file every minute! To change the rolling period adjust the DatePattern value. For example, a date pattern of “yyyyMMdd” will roll every day. See System.Globalization.DateTimeFormatInfo for a list of available patterns.

<appender name="RoyaltyAppender" type="log4net.Appender.RollingFileAppender">
<file value="tracker\modules\Royalty\" />
<appendToFile value="true" />
<rollingStyle value="Date" />
<maxSizeRollBackups value="30" />
<datePattern value="'RoyaltyLog'yyyyMMdd'.txt'" />
<staticLogFileName value="false" />
<layout type="log4net.Layout.XmlLayoutSchemaLog4j"/>
<lockingModel type="log4net.Appender.FileAppender+MinimalLock" />
</appender>

This example show how to configure the RollingFileAppender to roll log files on a date period and within a date period on file size. For each day only the last 10 files of 1MB will be kept.

<appender name="RollingLogFileAppender" type="log4net.Appender.RollingFileAppender">
    <file value="logfile" />
    <appendToFile value="true" />
    <rollingStyle value="Composite" />
    <datePattern value="yyyyMMdd" />
    <maxSizeRollBackups value="10" />
    <maximumFileSize value="1MB" />
    <layout type="log4net.Layout.PatternLayout">
        <conversionPattern value="%date [%thread] %-5level %logger [%property{NDC}] - %message%newline" />
    </layout>
</appender>

This example show how to configure the RollingFileAppender to roll log files once per program execution. The appendToFile property is set to false to prevent the appender from overwriting the existing files. ThemaxSizeRollBackups is set to negative 1 to allow an infinite number of backup files. The file size does have to be limited but here it is set to 50 Gigabytes which, if a log file exceeds this size limit during a single run then it will also be rolled.

<appender name="RollingLogFileAppender" type="log4net.Appender.RollingFileAppender">
    <file value="logfile.txt" />
    <appendToFile value="false" />
    <rollingStyle value="Size" />
    <maxSizeRollBackups value="-1" />
    <maximumFileSize value="50GB" />
    <layout type="log4net.Layout.PatternLayout">
        <conversionPattern value="%date [%thread] %-5level %logger [%property{NDC}] - %message%newline" />
    </layout>
</appender>