Why is log4net throwing LockRecursionException?

Question

I upgraded log4net to version 1.2.13 from 1.2.11 and now it throws the following exception whenever my application throws an exception:

Error: log4net:ERROR Exception while logging
log4net:ERROR Exception while logging
Error: System.Threading.LockRecursionException: Recursive read lock acquisitions not allowed in this mode.
    at System.Threading.ReaderWriterLockSlim.TryEnterReadLockCore(TimeoutTracker timeout)
    at System.Threading.ReaderWriterLockSlim.TryEnterReadLock(TimeoutTracker timeout)
    at System.Threading.ReaderWriterLockSlim.TryEnterReadLock(Int32 millisecondsTimeout)
    at System.Threading.ReaderWriterLockSlim.EnterReadLock()
    at log4net.Util.ReaderWriterLock.AcquireReaderLock()
    at log4net.Repository.Hierarchy.Logger.CallAppenders(LoggingEvent loggingEvent)
    at log4net.Repository.Hierarchy.Logger.ForcedLog(Type callerStackBoundaryDeclaringType, Level level, Object message, Exception exception)
    at log4net.Repository.Hierarchy.Logger.Log(Type callerStackBoundaryDeclaringType, Level level, Object message, Exception exception)

Logging works as usual when my application doesn't throw an exception. If someone can provide insight on why this might be happening I would greatly appreciate it.

Answer 1

In my application this apparently happens when a logger is accessed while logging a message. For example,

private static readonly ILog iLog = LogManager.GetLogger(
    MethodBase.GetCurrentMethod().DeclaringType);

public void Configure(){
    iLog.InfoFormat("Found project '{0}'.", GetProject());
    ... do stuff ...
}


private string GetProject()
{
   string result = null;
   iLog.Debug("Trying to determine project.");
   .... do stuff ...
   return result;
}

Apart from avoiding this situation I haven't found a fix yet.

Edit: After switching to NLog, logging worked out of the box, so I guess it is a bug in log4net. By the way, switching was effortless and NLog is easier to use, too.

Answer 2

log4net version 1.2.14 seems to have fixed this bug. See https://logging.apache.org/log4net/release/release-notes.html

[Update] I could reproduce this issue even with 1.2.15. It so happened that my local log DB was filled up and hence was seeing this error multiple times.