Log4net Rolling File Appender Configuration

Posted By admin On 12/01/22
Active5 years, 11 months ago

I have a Log4Net RollingFileAppender that is configured as:

Looking at the documentation, the The default rolling style is Composite, so it makes sense this will roll when it reaches a certain size (the default of 10MB), not just on the date.

If the file cannot be opened for writing when a message is logged then the message will be discarded by this appender. When rolling a backup file necessitates deleting an older backup file the file to be deleted is moved to a temporary name before being deleted. CAUTION A maximum number of backup files when rolling on date/time boundaries is not supported. Namespace: log4net.Appender. Assembly: log4net (in log4net.dll) See Also.


The problem is when it hits the size, it is restarting the log and I am losing the data from the first half of the day (it reaches this size around noon).
Why wouldn't this just roll to a new file and all future log lines are put into the MyLog.log?Or is it the log is rolling, but then at midnight, it is rolling again and overwritting the dated log (eg. rolling to MyLog.log2009-04-08 once it reaches 10MB, and then overwritting this same file at midnight)?

I will set the

Is this all I have to do to ensure it only rolls on the Date boundary? Can I change this on the fly in the Log4Net.config, or do I have to restart the application? It is running on IIS6.

Philipp M
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Tai SquaredTai Squared
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2 Answers

Here's my settings. It rolls only on date:

Log4net Rolling File Appender Configuration

Changes to your web.config, will restart the application automatically (so you'll lose sessions, etc).

Philipp M
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Rollingfileappender Configuration

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Try adding the maxSizeRollBackups parameter in your RollingFileAppender to solve half of our problem. This way, when the log file rolls, it won't overwrite your old log, but will roll it to another file.

Philipp M
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Rolling file cart

Log4net Rolling File Appender Configuration List


Log4net Rollingstyle

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