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  1. Log4net
  2. LOG4NET-552

Add new locking model to the FileAppender that works fine when multiple processes log and roll the same file

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    • Type: New Feature
    • Status: Open
    • Priority: Major
    • Resolution: Unresolved
    • Affects Version/s: 1.2.15
    • Fix Version/s: None
    • Component/s: Appenders
    • Labels:
    • Environment:
    • Flags:


      Hi Team,

      This issue has become blocker for us, as on our production environment, multiple processes are appending log into single log file which has no issue, but while rolling it overwrites files and thus missing log entries.

      Based on link below, it looks like log file rolling mechanism of log4net is not process safe even after using FileAppender.InterProcessLock.
      Link: https://issues.apache.org/jira/browse/LOG4NET-485

      Also, in FAQ (https://logging.apache.org/log4net/release/faq.html) under section “How do I get multiple process to log to the same file?”, it has been clearly mentioned that, rolling files is simply not compatible with multiple process scenario.

      My questions,
      1. We are using version “1.2.15”. Are you planning to fix above mentioned rolling issue in upcoming release? If yes then please provide tentative release date.
      2. We had incorporated log4net in our project in year 2009, had FAQ mentioned this limitation (rolling file not compatible with multi process) in year 2009? Because we while studying log4net during year 2009 we do not remember seeing this note in FAQ?

      Requesting you to please respond as soon as possible with your comments.

      Below is how we have configured appender for all processes,
      <appender name="RollingFileAppender" type="log4net.Appender.RollingFileAppender">
      <threshold value ="ERROR"/>
      <file value="${SystemDrive}\LogFiles\Example.log" />
      <param name="LockingModel" type="log4net.Appender.FileAppender+MinimalLock" />
      <appendToFile value="true" />
      <maximumFileSize value="100MB" />
      <staticLogFileName value="true"/>
      <maxSizeRollBackups value="-1" />
      <countDirection value="1" />
      <datePattern value=".yyyyMMddHH'.log'"/>
      <rollingStyle value="Composite" />
      <ignoreExceptionItemAgeLimit value="false" />
      <exceptionItemAgeLimit value="00:00:59" />

      <layout type="log4net.Layout.PatternLayout">
      <param name="conversionPattern" value ="%utcdate

      {yyyy-MM-dd HH:mm:ss.fff}








      Sachin Patil


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            • Assignee:
              ssachin3108 Sachin Abaso Patil


              • Created:

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