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From "Dominik Psenner" <dpsen...@gmail.com>
Subject AW: log4net rolling file appender losing log files during roll over
Date Wed, 15 Jan 2014 07:47:05 GMT
Good morning,


I've looked at the logfile [2] and all starts with the .log file not being
rolled cause the file is still open and thus can't be moved. The following
warnings are caused by the first error. So this is where the trouble starts:


log4net: Moving [c:\logs\mobile_deposit_web.log.5] ->

log4net: Moving [c:\logs\mobile_deposit_web.log.4] ->

log4net: Moving [c:\logs\mobile_deposit_web.log.3] ->

log4net: Moving [c:\logs\mobile_deposit_web.log.2] ->

log4net: Moving [c:\logs\mobile_deposit_web.log.1] ->

log4net: Moving [c:\logs\mobile_deposit_web.log] ->

log4net:ERROR [RollingFileAppender] ErrorCode: GenericFailure. Exception
while rolling file [c:\logs\mobile_deposit_web.log] ->

System.IO.IOException: The process cannot access the file because it is
being used by another process.

   at System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath)

   at System.IO.__Error.WinIOError()

   at System.IO.File.Move(String sourceFileName, String destFileName)

   at log4net.Appender.RollingFileAppender.RollFile(String fromFile, String

log4net:ERROR RollingFileAppender: INTERNAL ERROR. Append is False but
OutputFile [c:\logs\mobile_deposit_web.log] already exists.

log4net: Opening file for writing [c:\logs\mobile_deposit_web.log] append

log4net: rolling over count [104857887]

log4net: maxSizeRollBackups [100]

log4net: curSizeRollBackups [8]

log4net: countDirection [-1]


My first guess is that there are multiple processes logging into the same
file. That would mean that one process may holds a write lock on the file
while another one tries to roll the file. We have seen that people often are
not aware of the IIS app domain pool and its impact on the appender
configuration. If I'm right, then your usecase hints that there are probably
three ways to resolve the issue:


*         Use the InterProcessLock on the rolling file appender

o   this might produce a bottleneck for your high performance demands

*         Use remote appenders that sink log events to a remote process that
appends the events to the file

o   This might be a nice try

*         Replace the rolling file appender with an appender that sinks
events into a database or another storage that handles the write locks

o   Probably easier to configure than the remote appenders but the logs are
no longer stored as plain text in a file





Von: Douglas Neary [mailto:dneary@miteksystems.com] 
Gesendet: Dienstag, 14. Januar 2014 23:37
An: Log4NET User
Betreff: log4net rolling file appender losing log files during roll over




Under heavy strain, I am seeing log4net lose log files during roll over.   I
filed a bug yesterday (https://issues.apache.org/jira/browse/LOG4NET-416),
and I wanted to offer my help (and hardware) to help track it down.  I
attached the internal log4net log to the ticket.


The hardware we are using is pretty high end
4231377#!tab=features).    We are using this beast as a combined image
processor and web server, running IIS 7.5 on Windows Server 2008 R2.  


For every transaction processed, a line is written to log4net.   On average,
we are probably doing around 7 transactions per second.  This works fine for
a while, until it doesn't.   Then it starts losing log files during


Given all the value we have gotten out of log4net, my company is willing to
donate some of my time and some time on that DL980 to test out the fixes.


Is there anyone who can give me a push in the right direction?



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