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log4net multiple loggers - properties

log4net v. 2.0.8
I've got some problems in multiple logging with log4net. I'm developing an application that works with n devices and I would like to have a single log file for each device.
log4net.config
<log4net>
<appender name="LogFileAppender" type="log4net.Appender.RollingFileAppender">
<file type="log4net.Util.PatternString" value="%envFolderPath{LocalApplicationData}/Foo/Device%property{DeviceID}/log.txt"/>
<appendToFile value="true"/>
<maxSizeRollBackups value="10"/>
<maximumFileSize value="10MB"/>
<layout type="log4net.Layout.PatternLayout">
<param name="Header" value="BEGIN LOGGING AT %date *** %property *** %newline" type="log4net.Util.PatternString" />
<param name="Footer" value="END LOGGING AT %date *** %property *** %newline" type="log4net.Util.PatternString" />
<param name="ConversionPattern" value="%date [%thread] %-5level %-5class{1} %-5method(%line) %message %newline" />
</layout>
<filter type="log4net.Filter.PropertyFilter">
<key value="Version" />
<stringToMatch value="1" />
</filter>
</appender>
<root>
<level value="ALL" />
<appender-ref ref="LogFileAppender" />
</root>
and this is the code
public DeviceClass(string deviceID)
{
InitializeComponent();
GlobalContext.Properties["DeviceID"] = deviceID;
logger = LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);
logger.Debug("Hello world");
The problem is that if I have for example two devices I got just the first log file with the messages from all devices.

I'm not a Log4Net expert, but I believe that the log manager is going to initialize the logger and all of its appenders the first time that you call GetLogger for the given type/name (type under covers is translated to a string name). That being the case, it wouldn't re-initialize one per device. My suggestion for you is to try creating a composite of the type name and device ID using something like:
logger = LogManager.GetLogger($"{System.Reflection.MethodBase.GetCurrentMethod().DeclaringType.FullName}{deviceId}");

Log4net sometimes creating two logs, one empty

Using the below configuration, about half of the time, I'm getting two logs per one, one empty. They differ in filename by one second (log.2015-03-09_11-50-25 vs log.2015-03-09_11-50-26)
I'm trying to have one log per run of the console application.
<log4net>
<appender name="Log" type="log4net.Appender.FileAppender">
<file type="log4net.Util.PatternString" value="C:\env\QA\Logs\consoleapp\log.%date{yyyy-MM-dd_HH-mm-ss}.txt"/>
<appendToFile value="true"/>
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%date %message%newline"/>
</layout>
</appender>
<root>
<level value="INFO"/>
<appender-ref ref="Log"/>
</root>
</log4net>
The latter log is the only one that's populated/written to.
Why is this happening? How do I fix it?
EDIT: Turns out i was instantiating a second logger in my code. When the instantiation occurred during a different second, a second log was created. The appender was working correctly.

I've seen something similar before - it's due to the second being specified in the filename, and the writes are occuring during the end of one second and the start of another.
<file type="log4net.Util.PatternString" value="C:\env\QA\Logs\consoleapp\log.%date{yyyy-MM-dd_HH-mm-ss}.txt"/>
should be
<file type="log4net.Util.PatternString" value="C:\env\QA\Logs\consoleapp\log.%date{yyyy-MM-dd}.txt"/>
In my last job, somebody set the second specifier in the log file name, and the production server came close to crashing trying the render the 150,000 files contained in the log folder.
Edit:
If you want to write once per run, you can add the following to your log4net configuration:
<rollingStyle value="Once" />
and you might need to set the appendToFile attribute to be false.
log4net one file per run
so your config would look like this:
<appender name="Log" type="log4net.Appender.FileAppender">
<file type="log4net.Util.PatternString" value="C:\env\QA\Logs\consoleapp\log.%date{yyyy-MM-dd_HH-mm-ss}.txt"/>
<appendToFile value="false" />
<maxSizeRollBackups value="-1" /> <!--infinite-->
<rollingStyle value="Once" />
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%date %message%newline"/>
</layout>
</appender>

I used user1666620's solution, but still got a .log.1 file.
Turns out I had the following line in my AssemblyInfo.cs file:
[assembly: log4net.Config.XmlConfigurator(Watch = true)]
Removing the above line fixed my issue. By the way, my program.cs looks like:
public static class Program
{
static Program()
{
// Initialize logging
log4net.Config.XmlConfigurator.Configure();
}
private static readonly ILog log =
LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);
...
}

log4net doesn't produce a log file when my project is deployed with windows installer

When I log in my dev environment there is no problem but when I deploy with a windows installer no log files are produced:
<log4net>
<root>
<level value="ALL"/>
<appender-ref ref="LogFileAppender"/>
</root>
<appender name="LogFileAppender" type="log4net.Appender.RollingFileAppender">
<lockingModel type="log4net.Appender.FileAppender+MinimalLock"/>
<param name="File" value="C:\Logs\log-file.txt"/>
<param name="AppendToFile" value="true"/>
<rollingStyle value="Size"/>
<maxSizeRollBackups value="10"/>
<maximumFileSize value="10MB"/>
<staticLogFileName value="true"/>
<layout type="log4net.Layout.PatternLayout">
<param name="ConversionPattern" value="%date [%thread] %-5level %logger [%C{1}.%M] - %message%newline"/>
</layout>
</appender>
</log4net>
I read that it may be that it cannot find the app.config but how do I tell it where to find it?

The issue was that log4net couldn't find the config file at run time after the dll was installed. Fixed by a suggestion here. In the end, my solution looked like this:
FileInfo fi = new FileInfo(AppDomain.CurrentDomain.BaseDirectory + "Assembly.dll.config");
log4net.Config.XmlConfigurator.Configure(fi);
_log.Info("Hello logging...");
Thank you for all of your input!

The app.config project file is turned to the the application.exe.config file after compilation. Maybe you are not deploying it with the installer?

how to create dynamic log using log4net

My Project is in C# (Windows Form) .net3.5
In my code there are multiple events and in each event multiple searches are running.
I have to create log file for each event and multiple searches can access & write this single log file.
The problem is that I don't know how to use log4net for creating multiple logs with dynamic(set at run time) names.
How to set there location(Path)
I explorer internet regarding my problem but haven't found any help which address this type of issues.
any idea pls

log4net is generally used to have mutiple sources and appenders.
To generate a defined source, ask LogManager to have a named log, generally we use a type to identify a log, but feel free to use a string if you want:
var myLog = LogManager.GetLogger("NAME");
....
var myLog = LogManager.GetLogger(GetType());
In the first case logger is identified by "NAME", in the second by the type name with namespaces.
Then you can configure the appenders, for all logs, for a subset of them, with filters and so on.
Let's see an example:
<configuration>
<configSections>
<section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler, log4net"/>
</configSections>
<log4net>
<appender name="MYFILE" type="log4net.Appender.RollingFileAppender">
<file value=".\logs\myname.log"/>
<appendToFile value="true"/>
<rollingStyle value="Size"/>
<maxSizeRollBackups value="10"/>
<maximumFileSize value="10MB"/>
<staticLogFileName value="true"/>
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%date %-5level (%thread) %logger - %message%newline"/>
</layout>
</appender>
<root>
<level value="INFO"/>
<!-- all logger append to these appenders />
<appender-ref ref="xxxxxx"/>
</root>
<logger name="NAME">
<level value="INFO"/>
<appender-ref ref="MYFILE"/>
</logger>
<!-- add other appender here -->
Don't forget to call at your application start XmlConfigurator.Configure();

log4net EventLog custom logname created, but not used

In a project, i'm using log4net to write down in the event log. I need to create a custom log so all will go there. I have tried to add the event to different logs, and it worked, but for some reasons, now it is impossible to change the logname from the config file. Even if I change it, it will keep the previous one and log into it. Here is a sample of my app.config:
<appender name="EventLogAppender" type="log4net.Appender.EventLogAppender">
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%date{yyyy-MMMM-dd HH:mm:ss, fff} [%thread] %level %message %exception%newline"/>
</layout>
<filter type="log4net.Filter.LevelRangeFilter">
<levelMin value="DEBUG" />
<levelMax value="FATAL" />
</filter>
<ApplicationName>TestLoggerFichierConfig</ApplicationName>
<LogName>AgentLogger</LogName>
</appender>
I read that the event log must be restarted when adding a new log so the recent events will be displayed in it. I did this, and it allowed me to see the new log that has been created, but nothing will go there. Is it possible to force Log4Net to stop using the previous log to rather use the one I defined in the app.config?
Thanks for the help.
Update:
It seems that le EventLogs recognizes the source application and decide in wich log to put the new events since he remembers where it previously went. When I first set the logName, it works fine. If I stop the app, change the logname and restart it, the event will still go to the previous log. If the logName does not exists in the event log, it will be created, but not used! There might be something to do, but it is not in the side of log4net, and it may be dangerous to change the windows settings at this level. I created two eventLogAppender on the same app.config file, both pointing at different logs. the events got to the same log though. It is being obvious that the problem doesn't come from log4net, and the solution to my problem will not be solved by code. Thanks for the great advices though.

Something is probably wrong with your configuration and it is simply not telling you about it because log4net itself is designed to never, ever throw errors.
You can turn on internal debugging for log4net, but don't deploy to production with log4net debugging turned on. Weirdness will eventually happen if deploy your product with the log4net debugging switch on.
http://haacked.com/archive/2006/09/27/Log4Net_Troubleshooting.aspx
http://logging.apache.org/log4net/release/faq.html (see the troubleshooting section)

I ran into this and it wasn't down to log4net but the re-mapping of the source to a new custom log. I took log4net out of the equation and finding that the problem occurred usint the EventLog class directly, I eventually found EventLog.CreateEventSource is not creating a custom log
I think it's also the reason behind this Windows service always writes to custom log and application log

First and foremost, I'd encourage you to turn on internal debugging, as found in the link ntcolonel posted. Add this to your config file:
<add key="log4net.Internal.Debug" value="true"/>
Perhaps I am not understanding your question entirely, but I'd like to ensure you have both created the appender and properly tell log4net that you want to actually use that appender:
<log4net debug="true">
<appender name="RollingFileAppender" type="log4net.Appender.RollingFileAppender">
<file value="Logs\SomeApplication.xml"/>
<appendToFile value="true"/>
<rollingStyle value="Size"/>
<countDirection value="1"/>
<maxSizeRollBackups value="30"/>
<maximumFileSize value="10MB"/>
<staticLogFileName value="true"/>
<lockingModel type="log4net.Appender.FileAppender+MinimalLock"/>
<layout type="log4net.Layout.XmlLayoutSchemaLog4j">
<locationInfo value="true"/>
</layout>
</appender>
<appender name="SmtpAppender" type="log4net.Appender.SmtpAppender">
<to value="SomeDistributionList#somehost.com"/>
<from value="SomeApplication#somehost.com"/>
<subject type="log4net.Util.PatternString" value="Some Application Error - %property{log4net:HostName}"/>
<smtpHost value="smtp.somehost.com"/>
<bufferSize value="1"/>
<threshold value="ERROR"/>
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%date %property{log4net:HostName} %logger %level %newline%newline%property{ExceptionThrottleInformation}%newline%newline%message%newline"/>
</layout>
<filter type="SomeNamespace.SomeSubNamespace.Log4Net.ExceptionThrottleFilter, SomeSubNamespace">
<threshold value="10"/>
<thresholdTimeoutSeconds value="60"/>
<timeoutSecondsBetweenMessages value="600000"/>
<exceptionText value="Timeout expired"/>
</filter>
</appender>
<appender name="DatabaseAppender" type="SomeNamespace.SomeSubNamespace.DatabaseTraceAppender, SomeSubNamespace">
<hoursToKeepInformationalTraces value="48"/>
<hoursToKeepErrorTraces value="96"/>
<threshold value="INFO"/>
</appender>
<root>
<level value="INFO"/>
<appender-ref ref="RollingFileAppender"/>
<appender-ref ref="SmtpAppender"/>
<appender-ref ref="DatabaseAppender"/>
</root>
Note that while I have multiple appenders, I reference which to call within the root tag. Since you didn't post your whole config file, it's tough to tell if everything is matching as it should.