I am using Log4Net as the logging mechanism for an application of ours. Our configuration is contained in a config file and in our code we programatically invoke which of our several loggers (mostly using FileAppenders) we want to invoke. Recently I realized that one of our log files was not being populated, and I tracked it down to a string mismatch, between the name in our configuration file and the name we were programatically invoking in our code. Because the LogManager could not find the specified logger the root was returned, which for our config is not setup to meaningfully log anywhere.
My question is, is there a way to setup log4net to allow for using specific loggers, but that will fall back to a general logger if the specified logger is not found?
For example using a configuration file like this
<configuration>
<configSections>
<section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler,log4net" />
</configSections>
<log4net>
<root>
<level value="ALL" />
<appender-ref ref="ConsoleAppender" />
</root>
<logger name="TestFileLogger">
<level value="ALL" />
<appender-ref ref="TestFileAppender" />
</logger>
<appender name="ConsoleAppender" type="log4net.Appender.ConsoleAppender">
<layout type="log4net.Layout.PatternLayout">
<param name="ConversionPattern" value="%d [%t] %-5p [%x] - %m%n" />
</layout>
</appender>
<appender name="TestFileAppender" type="log4net.Appender.RollingFileAppender">
<param name="File" value="TestLog" />
<param name="DatePattern" value=".yyyyMMdd".log"" />
<param name="AppendToFile" value="true" />
</appender>
</log4net>
</configuration>
And invoking the loggers in C# like this
var fileLogger = LogManager.GetLogger("TestFileLogger");
fileLogger.Info("This logs appropriately.");
var bogusLogger = LogManager.GetLogger("Bogus");
bogusLogger.Info("This should go to a general log. Bogus is not a recognized appender");
Is there a good way to log the messages from bogusLogger to some kind of general log file? My initial thought was to create a general file appender that is part of the root node, but this is very noisy as ALL log messages will be routed to this file. Is there a way to ONLY route messages that are not captured in another log file?
You could use LogManager.Exists("Bogus") to determine if the bogus-logger or your default implementation should be used.
You could create an extensionmethod on LogManager that could handle it for you.
Related
I am creating a logging component using log4net in my project. I've created an xml file to configure the log4net settings including an append-er and logger definition. I'm using PatternString to pick up properties' value from the appsetting.config file. However when I build and run the project, it throws the following error:
log4net:ERROR Undefined level [%property{Level}] on Logger [Test].
Does anyone know what might be causing it?
XML:
<?xml version="1.0" encoding="UTF-8" ?>
<log4net>
<logger name="Test">
<level type="log4net.Util.PatternString" value="%property{Level}" />
<appender-ref ref="JsonFileAppender" />
</logger>
</log4net>
appsetting.config:
<appSettings>
<add key="Level" value="ALL"/>
</appSettings>
In case it's useful the log4net version is: version:2.0.8
Good question!
I learnt from this, a lot.
Please don't forget to call this method before start logging.
log4net.Config.XmlConfigurator.Configure();
app.config is.
if you need apply pattern, use <layout> element.
and if you want to use some value from "appSettings",
use like this, %appSetting{Environment}
<?xml version="1.0" encoding="utf-8"?>
<configuration>
<configSections>
<section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler, log4net" />
</configSections>
<log4net>
<appender name="ConsoleAppender" type="log4net.Appender.ConsoleAppender" >
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%date [%thread] %-5level %logger [%ndc] - %message%newline" />
</layout>
</appender>
<root>
<level value="%appSetting{Environment}" />
<appender-ref ref="ConsoleAppender" />
</root>
</log4net>
<appSettings>
<add key="Environment" value="INFO" />
<!-- this is optional flag.-->
<add key="log4net.Internal.Debug" value="True" />
</appSettings>
</configuration>
Here is where I learned
Accessing appSettings config values from log4net config section
https://logging.apache.org/log4net/release/manual/configuration.html
https://www.paraesthesia.com/archive/2010/11/12/log4net-appsettings-keys.aspx/
The reason for this error is because the level of a logger can't be configured via a PatternString.
The <level> elements expects a wellknown value, like eg. ALL, DEBUG, INFO, WARN, ERROR,
eg.:
<logger name="Test">
<level value="All" />
</logger>
From your setup I read that you are trying to apply a setting from AppSettings.config upon the log level of a logger in your Log4net configuration.
As explained above, this can't be done.
Either keep all Log4net related settings within its own xml - in the end it is also configuration.
Or set the level programmatically;
you will have to translate the string value in appsettings.config to a Level yourself.
logger = LogManager.GetLogger("Test");
Level level = // Parse from ConfigurationManager.AppSettings["Level"]
((Logger)logger.Logger).Level = level;
The Story: I have a WinForms application with multiple assemblies - MainApp and Utilities. I use Utilities for my logging via log4net. All is fine with the world if I use a separate config file for log4net (aka log4net.config) - no issues.
However, IT staff finds it challenging to tweak two .config files (MainApp.exe.config and log4net.config). So, I'm trying to add my log4net config settings into my app.config file. Not having any luck.
I've tried several solutions posted in this forum. This one seemed to experience the same error I get:
log4net configuration - failed to find section
I've tried putting this line in my Utilities:AssemblyInfo.cs
[assembly: log4net.Config.XmlConfigurator(ConfigFile = "MainApp.exe.config", Watch = false)]
In my Utilities module where log4net is referenced, I have this:
const string TEMP_VARIABLE = "TEMP";
string tempDir = Environment.GetEnvironmentVariable( TEMP_VARIABLE );
StringBuilder userTempDirLogFile = new StringBuilder( tempDir );
userTempDirLogFile.Append( #"\" );
userTempDirLogFile.Append( Environment.MachineName );
userTempDirLogFile.Append( "_MAIN_" );
userTempDirLogFile.Append( DateTime.Now.DayOfWeek );
userTempDirLogFile.Append( ".log" );
log4net.GlobalContext.Properties["MainLogFileName"] = userTempDirLogFile.ToString();
StringBuilder utilityLogFile = ( userTempDirLogFile.Replace( "_MAIN_", "_UTILITIES_" ) );
log4net.GlobalContext.Properties["UtilityLogFileName"] = utilityLogFile.ToString();
log4net.Config.XmlConfigurator.Configure();
_mainLogger = LogManager.GetLogger( "MAIN" );
_mainLogger gets this error message:
log4net:ERROR XmlConfigurator: Failed to find configuration section 'log4net' in the application's .config file. Check your .config file for the <log4net> and <configSections> elements. The configuration section should look like: <section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler,log4net" />
I noticed in log4net source code that log4net.Config.XmlConfigurator.Configure() calls Assembly.GetCallingAssembly(). I've verified that GetCallingAssembly() is indeed MainApp. My program directory contains all necessary files.
This is my app.config
<?xml version="1.0"?>
<configuration>
<!-- configSections MUST be first! -->
<configSections>
<section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler,log4net" />
</configSections>
<log4net>
<appender name="MainLogFile" type="log4net.Appender.RollingFileAppender">
<file type="log4net.Util.PatternString" value="%property{MainLogFileName}"/>
<appendToFile value="false" />
<maximumFileSize value="20MB" />
<maxSizeRollBackups value="3" />
<param name="Encoding" value="unicodeFFFE" />
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%date{ISO8601} %property{messageId} %-5level %message%newline" />
</layout>
<filter type="log4net.Filter.LevelRangeFilter">
<param name="LevelMin" value="ALL" />
<param name="LevelMax" value="OFF" />
</filter>
</appender>
<appender name="UtilityLogFile" type="log4net.Appender.RollingFileAppender">
<file type="log4net.Util.PatternString" value="%property{UtilityLogFileName}"/>
<appendToFile value="false" />
<maximumFileSize value="20MB" />
<maxSizeRollBackups value="3" />
<param name="Encoding" value="unicodeFFFE" />
<layout type="log4net.Layout.PatternLayout">
<conversionPattern value="%date{ISO8601} %property{messageId} %-5level %message%newline" />
</layout>
<filter type="log4net.Filter.LevelRangeFilter">
<param name="LevelMin" value="ALL" />
<param name="LevelMax" value="OFF" />
</filter>
</appender>
<logger name="MAIN">
<level value="DEBUG" />
<appender-ref ref="MainLogFile" />
</logger>
<logger name="UTILITY">
<level value="DEBUG" />
<appender-ref ref="UtilityLogFile" />
</logger>
</log4net>
<startup>
<!-- Leave sku out so that both 4.0 and 4.5 are supported -->
<supportedRuntime version="v4.0" />
</startup>
<system.windows.forms jitDebugging="true" />
<system.diagnostics>
<trace useGlobalLock="false" />
</system.diagnostics>
<appSettings>
<add key="PRINT_CALL_STACK" value="false"/>
<add key="TRACK_PERFORMANCE" value="false"/>
<add key="USING_TEST_MODE" value="false"/>
<add key="WAIT_FOR_LOGON" value="0"/>
</appSettings>
</configuration>
I figure I'm missing something, but no clue as to what. Thanks for your time.
Note: using VS2013 and log4net 1.2.13.0. Solution targets .NET 4.0 full and x86.
If you want to put everything in your app.config, make sure you have this in the AssemblyInfo.cs:
[assembly: log4net.Config.XmlConfigurator(ConfigFileExtension = "config", Watch = true)]
true or false can be changed if you want to monitor dynamically or not the config file for changes.
and in your config file, make sure you have the appropriate sections. For example in mine I have:
<configSections>
<section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler, log4net" />
</configSections>
<log4net>
<appender name="FileAppender" type="log4net.Appender.FileAppender">
<param name="file" value="logs/App.log"/>
<param name="appendToFile" value="True"/>
<param name="encoding" value="utf-8"/>
<param name="staticLogFileName" value="False"/>
<param name="RollingStyle" value="Size"/>
<param name="MaxSizeRollBackups" value="1"/>
<param name="MaxFileSize" value="10485760"/>
<param name="threshold" value="Debug"/>
<layout type="log4net.Layout.PatternLayout">
<param value="%d [%t] %-5p %c{2} - %m%n" name="conversionPattern"/>
</layout>
</appender>
<root>
<level value="INFO" />
<appender-ref ref="FileAppender" />
</root>
</log4net>
If you put log4net configuration setting into the app.config or the web.config file the put into the AssemblyInfo.cs file in the Properties folder of your project the following line:
[assembly: log4net.Config.XmlConfigurator(Watch = true)]
Quote from the manual:
// Configure log4net using the .config file
[assembly: log4net.Config.XmlConfigurator(Watch=true)]
// This will cause log4net to look for a configuration file
// called TestApp.exe.config in the application base
// directory (i.e. the directory containing TestApp.exe)
// The config file will be watched for changes.
The assembly attribute must be in the MainApp project, not in the Utilities project.
As it says in the documentation for assembly attributes
Therefore if you use configuration attributes you must invoke log4net
to allow it to read the attributes. A simple call to
LogManager.GetLogger will cause the attributes on the calling assembly
to be read and processed. Therefore it is imperative to make a logging
call as early as possible during the application start-up, and
certainly before any external assemblies have been loaded and invoked.
This is my first time ever using Log4Net so I'm sure I'm doing something really dumb.
In App.config, inside the <configuration> tag, I have the following:
<log4net>
<appender name="LogFileAppender" type="log4net.Appender.FileAppender">
<param name="File" value="log-file.txt" />
<param name="AppendToFile" value="true" />
<layout type="log4net.Layout.PatternLayout">
<param name="Header" value="[Header]\r\n" />
<param name="Footer" value="[Footer]\r\n" />
<param name="ConversionPattern" value="%d [%t] %-5p %c [%x] <%X{auth}> - %m%n" />
</layout>
</appender>
<root>
<level value="WARN" />
<appender-ref ref="LogFileAppender" />
</root>
</log4net>
In my Program.cs file I catch a ConfigurationException:
Message: Configuration system failed to initialize
InnerException: Unrecognized configuration section log4net.
But I copy-pasted the configuration code straight out of the .NET example they provide on their website. I read over their documentation but it's pretty confusing for someone who has never used any sort of logging framework before. I also found a few tutorials on CodeProject that hold your hand better but can't piece out what I've done wrong. I tried putting the <root> element before the <appender> element and that gives me the same ConfigException. And yes I've added a reference to the DLL to the project.
Sounds like you just forgot to include the configSection entry for log4net:
<configuration>
<configSections>
<section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler,log4net" />
</configSections>
<!-- other configurations, such as appSettings and whatnot -->
<log4net>
<!-- log4net configuration that you already have -->
</log4net>
</configuration>
In order to use the log4net config node the system needs to be told how to interpret that node, which is handled in the log4net.Config.Log4NetConfigurationSectionHandler class.
I have been trying to use the class located here . But I have not been able to get this to work. I obviously do not understand something correctly, But I am curious how to get that example Logger class to work.
My research has sent me towards using MSBuild but the use of MSBuild correctly is still baffeling me. Any pointers would be helpful. I have built the logger class into a .dll,and referenced it in the project as well, but that is where my research seemed to run dry with helpful information.
My goal currently is just to get the above noted logger class working so I can use my own logger class.
That class is specifically for logging MSBuild events. If you want a generic logger that has nothing to do with MSBuild look at some of these alternatives:
MS Enterprise Library - Logging Application Block
Log4Net
Elmah (designed for logging ASP.NET errors, but can be used to log other events)
NLog
Don't be afraid of using a library to do the work. In the tutorial here for log4net it's a simple seven step process to start using a fully functional and scalable logging library. I'm going to inline pieces of the tutorial just in case the link ever dies.
First you build a very simple configuration section in your App.config file:
<configuration>
<configSections>
<section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler,Log4net"/>
</configSections>
<log4net>
<root>
<level value="DEBUG" />
<appender-ref ref="LogFileAppender" />
</root>
<appender name="LogFileAppender" type="log4net.Appender.RollingFileAppender" >
<param name="File" value="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 [%property{NDC}] - %message%newline" />
</layout>
</appender>
</log4net>
</configuration>
For your needs you pretty much just need to change the value of the first param named File as it's already setup to append to a text file.
Next you'll need to run the configuration in some startup method, like Application_Start or the main method of your program.
log4net.Config.XmlConfigurator.Configure();
Finally, just use it by plugging in a couple of lines:
private static readonly ILog log = LogManager.GetLogger(typeof(Bar));
... (rest of class)
... (somewhere in a method) ... log.Debug("this is the first log message");
After lots of issues, finally I managed to configure log4net for my window service.
I am pretty new to it and today I started configuring it. I have these below doubts.
1) I need to use that into multiple assemblies. Say I have an assembly 'A' which is added as reference in assembly 'B' which is mine main assembly where I have reference of log4net.I need to log both assembly 'A' and 'B'.
2) My application is multi-threaded and use lots of thread. So is log4net is thread safe?
3) I am using this below config in my app.config. I am not much aware what’s the use of it. But I don’t want to use unnecessary parameters.
<log4net>
<root>
<level value="DEBUG"/>
<appender-ref ref="LogFileAppender"/>
</root>
<appender name="LogFileAppender" type="log4net.Appender.RollingFileAppender">
<param name="File" value="C:\logs\log.txt"/>
<param name="AppendToFile" value="true"/>
<rollingStyle value="Size"/>
<maxSizeRollBackups value="10"/>
<maximumFileSize value="100KB"/>
<staticLogFileName value="true"/>
<layout type="log4net.Layout.PatternLayout">
<param name="ConversionPattern" value="%-5p%d{yyyy-MM-dd hh:mm:ss} – %m%n"/>
</layout>
</appender>
</log4net>
Use <lockingModel type="log4net.Appender.FileAppender+MinimalLock" /> under appender section. I twill increase the logging performance.
log4net is threadsafe.
<maximumFileSize value="10MB" /> //For 100 Kb configuration there will be lot of files.
<datePattern value="_yyyyMMdd" /> //It will hint the logger to create a new file per date.
Create a static class for Logger and call the static function from every assembly where you want to use.
Sample Class for logging:
public static class Logger
{
static Logger()
{
XmlConfigurator.Configure();
}
public static void Log()
{
string methodName = new System.Diagnostics.StackFrame(1, true).GetMethod().Name;
string moduleName = new System.Diagnostics.StackFrame(1, true).GetMethod().ReflectedType.FullName;
var appLog = LogManager.GetLogger(loggername);
appLog.Error(...);
}
}
that's not a problem; just use ILog as usual in assembly B.
just make sure you call Configure() once in your application's lifetime.
Yes.
I recommend familiarizing yourself with log4net. a simple google search or a look at the docs should do the trick.
<root>
<level value="DEBUG"/>
<appender-ref ref="LogFileAppender"/>
</root>
It will log only in debug mode, so make following entry in config:
<root>
<level value="ALL"/>
<appender-ref ref="LogFileAppender"/>
</root>