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Class will not log to a file with log4net

I've got a MVC based C# Windows Forms application. I've got the following configuration in the app.config file:
<log4net>
<root>
<level value="ALL"/>
<appender-ref ref="LogConsoleAppender"/>
<appender-ref ref="RollingLogFileAppender"/>
</root>
<appender name="LogConsoleAppender" type="log4net.Appender.ConsoleAppender">
<layout type="QAC.Source.Services.Log.LogPatternLayout">
<conversionPattern value="%date %level [Thread: #%thread] %message [%logger -> %M]%newline"/>
</layout>
</appender>
<appender name="RollingLogFileAppender" type="log4net.Appender.RollingFileAppender">
<file value="logs/QAC_"/>
<datePattern value="yyyy-MM-dd_HH-mm-ss'.log'"/>
<staticLogFileName value="false"/>
<appendToFile value="false"/>
<rollingStyle value="Date"/>
<maxSizeRollBackups value="50"/>
<maximumFileSize value="10MB"/>
<layout type="QAC.Source.Services.Log.LogPatternLayout">
<conversionPattern value="%date %level [Thread: #%thread] %message [%logger -> %M]%newline"/>
</layout>
</appender>
</log4net>
In the main method, in the first lin, I call private static ILog log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType); and after that I initialize my main service:
mainService = MainFactory.getMainServiceInstance();
And there is the problem. All log outputs in the main method are logged successfully to the file and console, also of other services (underlying services from MainService). The only class which is not logged is the MainService. The curiosity at this is, that the logging for this class starts after some time. I don't use any filter. I've turned on the log4net debugging:
<add key="log4net.Internal.Debug" value="true"/>
, but there is no error at least. So I think, that the initialization goes through. Also if I log before I initialize the MainService, it also logs to console and file. Just this class will not log.
Any help would be very nice. Thank you in advance.

I've found the solution. I am using a custom LogPatternLayout which tries also to initialize the MainService and so the MainService is initialized before the LogPatternLayout could be read and initialized into the Logger. Therefore logging takes place after the initialization of the MainService.

Not able to get log4net working to write to file

I am using sharpdevelop to create a console application in C#. I have added in the reference for log4net and I added my logging statements while I was writing the code but I never looked at the log file. Now I am done with the code I need to get the log file working. My program runs fine, even the logging statements, but I can't find the log file.
I have tried to cobble together a couple of examples on getting log4net working. I have the lines to read from the configuration and then to instantiate the object, these are the first lines in my program to run:
log4net.Config.XmlConfigurator.Configure();
ILog datalogger = LogManager.GetLogger("myLog"); //initiate the data logger
Then in various places throughout the code I have this:
datalogger.Info(DateTime.Now.ToString() + ": using file: " + ProDirectory.ToString() + #"\" + myProFile.ToString());
I have also put the following in my app.config file:
<appender name="myLogAppender" type="log4net.Appender.RollingFileAppender" >
<file value="myLog.log" />
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%date %level - %message%n" />
</layout>
</appender>
<logger name="myLog">
<level value="All"></level>
<appender-ref ref="myLogAppender" />
</logger>
No matter what I do, I can't see the log file being produced. I have changed the directory and even paused the program to see if I could find a handle open to the log file. Each time I come up empty. Not sure what I could be doing wrong.

not sure if this will help. I also had hard times making log4net work in different scenarios.
I use log4net root xml node to specify the appender. hope it will help.
<log4net>
<appender name="RollingFileAppender" type="log4net.Appender.RollingFileAppender">
<file value="log.txt" />
<appendToFile value="true" />
<rollingStyle value="Size" />
<maxSizeRollBackups value="10" />
<maximumFileSize value="250KB" />
<staticLogFileName value="true" />
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%date [%thread] %-5level %logger [%property{NDC}] - %message%newline" />
</layout>
</appender>
<root>
<level value="DEBUG" />
<appender-ref ref="RollingFileAppender" />
</root>
UPDATE
You might also want to check Visual Studio output log. First setup the output log to log "ALL" (somewhere in VS settings). Then you should see exact error message of log4net in the output window of Visual Studio.

Whenever I have had issues with log4net creating the log file, it usually wound up being a file / directory permissions issue.
Change your <file value="log.txt" /> to something that you know will be accessible by the current user / process running devhost.
For example: <file value="%USERPROFILE%\Documents\log.txt" /> will create a log file in the user's My Documents folder. This is a folder that the user has permissions to write data to, and shouldn't give you any troubles with.
For more information on special folder values, see this link.

Looks like I just had to clean up my XML a little, after I did the log file is working fine:
<?xml version="1.0" encoding="utf-8"?>
<configuration>
<configSections> <!-- Level 1 -->
<section name="log4net"
type="log4net.Config.Log4NetConfigurationSectionHandler,
log4net"/> <!-- Level 2 -->
</configSections>
<startup>
<supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.0" />
</startup>
<log4net>
<appender name="myLogAppender" type="log4net.Appender.RollingFileAppender" >
<file value="myLog.log" />
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%date %level - %message%n" />
</layout>
</appender>
<logger name="myLog">
<level value="All"></level>
<appender-ref ref="myLogAppender" />
</logger>
</log4net>
</configuration>

Logging in an application

I built an application and want to use logging in my application before giving it out to a user to know the actions the user did in case before any error. I haven't used logging before, so I did a bit of study to find out good methods for the same and perhaps Trace class in .NET looks like what might help in this scenario.
Using a text file seems to be a better idea here for the logging setting a TextWriterTraceListener in the App.Config file of my project, and using in the code Trace.Writeline("Error info", "Field");
1) Even after reading good amount of content, I am not sure about good approaches for logging? Should there be different error logger and information logging files? How does logging work for specifying different types of error (such as warning, critical, error etc.?)
2) I want to use the same logfile in one of my other projects in the solution. So, do I add the same Trace Listener section in the App.Config of my project?

With a logging library (such as log4net), you can do all the things you are asking about easily. You can set up your logging in a config file to go to event log, file, console, etc (or any combination) and set the logging levels independently.
That is, you can say the file will have informationals, warnings, errors, and fatals, but the event log will log only the errors and fatals.
In general, nearly all of the logging libraries have these features. The examples below are just in terms of log4net but the same concepts apply to most logging libraries...
To get the logger in any class in your solution, you just need to ask for a logger in your class:
public MyClass
{
private static readonly ILog _log = log4net.LogManager.GetLogger(typeof(MyClass));
public void SomeMethod()
{
_log.Debug("This is a debug message.");
_log.Info("This is an informational message.");
_log.Warn("This is a warning message.");
_log.Error("This is an error message.");
_log.Fatal("This is a fatal message.");
}
}
In addition, you can filter based on the loggers, that is, you could suppress log messages from paraticular classes or only display logging messages for a subset of classes, etc.
A sample config settings block would look like this. This creates a rolling file appender (keeps several days worth of logs) and Console appender
<log4net>
<appender name="RollingFileAppender" type="log4net.Appender.RollingFileAppender">
<file value="c:\logs\AgentLog"/>
<appendToFile value="true"/>
<datePattern value=".yyyy-MM-dd"/>
<rollingStyle value="Date"/>
<MaxSizeRollBackups value="14"/>
<param name="StaticLogFileName" value="false"/>
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%d{HH:mm:ss.fff} [%thread] %-5level %logger{1} - %m%n"/>
</layout>
</appender>
<appender name="ColoredConsoleAppender" type="log4net.Appender.ColoredConsoleAppender">
<mapping>
<level value="FATAL"/>
<foreColor value="Yellow"/>
<backColor value="Red, HighIntensity"/>
</mapping>
<mapping>
<level value="ERROR"/>
<foreColor value="Red, HighIntensity"/>
</mapping>
<mapping>
<level value="WARN"/>
<foreColor value="Yellow, HighIntensity"/>
</mapping>
<mapping>
<level value="INFO"/>
<foreColor value="Green, HighIntensity"/>
</mapping>
<mapping>
<level value="DEBUG"/>
<foreColor value="White"/>
</mapping>
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%d{HH:mm:ss.fff} [%thread] %-5level %logger{1} - %m%n"/>
</layout>
</appender>
<root>
<level value="INFO"/>
<appender-ref ref="RollingFileAppender"/>
<appender-ref ref="ColoredConsoleAppender"/>
</root>
</log4net>

With log4net, do you specify which appender to use?

When you have 2 appenders, say one for debug errors and one for product errors, in your code, do you explicitly create 2 log classes or is an appender basically going to write any log messages that meet a certain criteria?
So in your code, you use a single log method, and depending on how your appenders are setup, it will log the message if it e.g. is logged from a specific namespace, or is a certain log level.
So its possible a single log entry is written to 2 log files?

Yes, you can have single log statements post to multiple appenders. As long as it meets the criteria for each, it will use each appender.
For example, take this config section, it logs all messages to file, and also logs warnings and errors to event viewer.:
<log4net>
<appender name="RollingFileAppender" type="log4net.Appender.RollingFileAppender">
<file value="c:\logs\MySite"/>
<appendToFile value="true"/>
<datePattern value=".yyyy-MM-dd.\l\o\g"/>
<rollingStyle value="Date"/>
<MaxSizeRollBackups value="14"/>
<param name="StaticLogFileName" value="false"/>
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%d{HH:mm:ss.fff} [%thread] %-5level %logger{1} - %m%n"/>
</layout>
</appender>
<appender name="EventLogAppender" type="log4net.Appender.EventLogAppender">
<applicationName value="Trading.Web"/>
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%d{HH:mm:ss.fff} [%thread] %-5level %logger{1} - %m%n"/>
</layout>
<filter type="log4net.Filter.LevelRangeFilter">
<param name="LevelMin" value="WARN"/>
<param name="LevelMax" value="ERROR"/>
</filter>
</appender>
<root>
<level value="DEBUG"/>
<appender-ref ref="RollingFileAppender"/>
<appender-ref ref="EventLogAppender" />
</root>
</log4net>
So this:
_log.Debug("This is a debug message");
Will only appear in the log file (because it doesn't meet the event log appender's filter criteria).
But this:
_log.Error("This is an error message.");
Will log to both the log file and the event viewer.
UPDATE: On your filtering question, if you had:
<root>
<level value="DEBUG"/>
<appender-ref ref="RollingFileAppender"/>
</root>
<!-- Print only messages of level WARN or above in the namespace Com.Foo -->
<logger name="Com.Foo">
<level value="WARN" />
</logger>
Then all things under Com.Foo will log if WARN or higher, but everything else would log at DEBUG or higher....

log4net not working in dll

I'm currently having issues with getting log4net to work within a particular dll. I'm currently using log4net in other dlls being called by my test app and logging is working fine within those dlls and also within my test app. It's this one particular dll that I'm having trouble with. Here is snippet of code from the dll I'm having trouble with.
//This is from ABC.dll
public class SessionFactory
{
protected static ISessionFactory sessionFactory;
private static readonly ILog log = LogManager.GetLogger(typeof(SessionFactory));
private static void Init()
{
try
{
//Read the configuration from hibernate.xml.cfg or app.config
Configuration normalConfig = new Configuration().Configure();
ConfigureNhibernateValidator(normalConfig);
log.Debug("Initializing session factory");
sessionFactory = Fluently.Configure(normalConfig)
.Mappings(m =>
m.FluentMappings
.AddFromAssemblyOf<OrderHeaderMap>()
.Conventions.AddFromAssemblyOf<PascalCaseColumnNameConvention>())
.ProxyFactoryFactory("NHibernate.ByteCode.LinFu.ProxyFactoryFactory, NHibernate.ByteCode.LinFu")
.BuildSessionFactory();
log.Debug("Finished initializing the session factory");
}
catch(Exception ex)
{
//Code not shown
}
}
}
In my test app I am calling:
log4net.Config.XmlConfigurator.Configure();
Here is my log4net configuration in my App.config file:
<configuration>
<configSections>
<section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler, log4net"/>
</configSections>
<log4net>
<!-- ALL|DEBUG|INFO|WARN|ERROR|FATAL|OFF -->
<root>
<level value="DEBUG"/>
<appender-ref ref="SpeedTest"/>
</root>
<!-- This is a default logger that nhibernate uses to push out all the SQL statements to-->
<logger name="NHibernate.SQL" additivity="false">
<level value="DEBUG"/>
<appender-ref ref="NHibernateConsoleLog"/>
<appender-ref ref="NHibernateFileLog"/>
</logger>
<!-- This is a default logger that nhibernate uses to push out all the debugging type information to-->
<logger name="NHibernate" additivity="false">
<level value="DEBUG"/>
<appender-ref ref="NHibernateFileLog"/>
</logger>
<appender name="NHibernateConsoleLog" type="log4net.Appender.TraceAppender">
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%date [%thread] %-5level %logger [%property{NDC}] - %message%newline"/>
</layout>
</appender>
<appender name="NHibernateFileLog" type="log4net.Appender.RollingFileAppender">
<file value="Logs/nhibernate.txt" />
<appendToFile value="true" />
<rollingStyle value="Size" />
<maxSizeRollBackups value="10" />
<maximumFileSize value="10MB" />
<staticLogFileName value="true" />
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%d{HH:mm:ss.fff} [%t] %-5p %c - %m%n" />
</layout>
</appender>
<appender name="SpeedTest" type="log4net.Appender.RollingFileAppender">
<file value="Logs/SpeedTest.txt" />
<appendToFile value="true" />
<rollingStyle value="Size" />
<maxSizeRollBackups value="10" />
<maximumFileSize value="10MB" />
<staticLogFileName value="true" />
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%d{HH:mm:ss.fff} [%t] %-5p %c - %m%n" />
</layout>
</appender>
</log4net>
</configuration>
Again logging is working fine within my test application using the SpeedTest appender but the logging within the above snippet of code is not working. I set breakpoints above on when it initializes the logger and it seems to hit it. I can post the log4net debug output if necessary but I didn't really see much. Just let me know if you need it and I will post.
Any suggestions as to why logging is not being recorded in the above snippet of code?

It seems that this issue was stemming from me changing the directory to all my external dependencies (log4net being one of them) awhile back in TFS. All I did was drop all my references in my visual studio project and re-add them from my new dependencies folder and everything worked as expected after this. Thanks for all those that helped here.

My suspicion would be that it isn't reading the configuration from the configuration file when you call configure.
If you add the following lines to your application, what do you see (either on the console, or in IDE output window, or by stepping through in the debugger):
var log4netConfig = ConfigurationManager.GetSection("log4net");
var log4netConfigIsNull = log4netConfig == null;
Console.WriteLine(log4netConfigIsNull);
Does it look like the configuration is actually available from the configuration file?
[Edit: in response to your comment]
If you now add another line of debug code to your app:
Console.WriteLine(log.IsDebugEnabled);
what output do you get? Does the logger think it is configured for debug logging? (I'm particularly interested in the behaviour of this in, or after, SessionFactory.Init).

The immediate thought would be that your logging code isn't getting hit, possibly due to an exception being thrown prior to your first log4net call. Can you put a log entry into a finally block, just to test that the logger works?