Questions tagged [log4net]

The Apache log4net library is a tool to help the programmer output log statements to a variety of output targets. log4net is a port of the excellent Apache log4j™ framework to the Microsoft® .NET runtime. We have kept the framework similar in spirit to the original log4j while taking advantage of new features in the .NET runtime.

Apache log4net is a tool to help the programmer output log statements to a variety of output targets. In case of problems with an application, it is helpful to enable logging so that the problem can be located. With log4net it is possible to enable logging at runtime without modifying the application binary. The log4net package is designed so that log statements can remain in shipped code without incurring a high performance cost. It follows that the speed of logging (or rather not logging) is crucial.

At the same time, log output can be so voluminous that it quickly becomes overwhelming. One of the distinctive features of log4net is the notion of hierarchical loggers. Using these loggers it is possible to selectively control which log statements are output at arbitrary granularity.

log4net is designed with two distinct goals in mind: speed and flexibility.

Features:

  • Support for multiple frameworks
  • Output to multiple logging targets
  • Hierarchical logging architecture
  • XML Configuration
  • Dynamic Configuration
  • Logging Context
  • Proven architecture
  • Modular and extensible design
  • High performance with flexibility

Support for multiple frameworks:

log4net runs on all ECMA CLI 1.0 compatible runtimes. log4net has specific builds for the following frameworks:

  • Microsoft® .NET Framework 1.0
  • Microsoft .NET Framework 1.1
  • Microsoft .NET Framework 2.0
  • Microsoft .NET Framework 3.5
  • Microsoft .NET Framework 4.0
  • Microsoft .NET Framework 3.5 Client Profile
  • Microsoft .NET Framework 4.0 Client Profile
  • Microsoft .NET Compact Framework 1.0*
  • Microsoft .NET Compact Framework 2.0
  • Mono 1.0
  • Mono 2.0
  • Microsoft Shared Source CLI 1.0*
  • CLI 1.0 Compatible
  • Microsoft .NET Core 1.0 providing .NET Standard 1.3

The "Client Profile" builds are stripped down versions of the "normal" builds that don't contain any ASP.NET releated code - which for example means the %aspnet-* patterns and the AspNetTraceAppender are not available.

* Not supported by the binary release but can be built from the source release.

Official Website: http://logging.apache.org/log4net/

Useful Links:

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log4net versus TraceSource

In this thread many people have indicated that they use log4net. I am a fan of TraceSources and would like to know why log4net is used. Here is why I like trace sources: Pluggable listeners - XML, TextFile, Console, EventLog, roll your…
Paul Stovell
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How to configure log4net to print to console in debug mode

Is there a way to configure log4net to print logs both to console and to files during debug? I am trying to find a way to debug my software efficiently by observing the logs immediately when they happen. Writing to files is problematic for me for…
user829174
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log4net: Configure to ignore messages from a specific class

Is there a way to have the log4net configuration ignore a specific class? For example, we generally create a log in every class. Similar to this: private static readonly ILog Log = log4net.LogManager.GetLogger("MyClass"); The problem is MyClass…
Kyle
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Log4Net configuring log level

How do I make Log4net only log Info level logs? Is that even possible? Can you only set a threshold? This is what I have, and it logs Info and above as I would expect. Is there anything i can do to make it only log info?
Dan
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Configure Log4Net in web application

I have this code and the config file below: ILog log = LogManager.GetLogger(typeof(MyClass)); log.Debug("Testing"); TestProj directory is not created and if I create it, no TestLog.txt file, no log ... nothing. Any idea? Thanks, The config…
TheBoubou
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Change log4net logging level programmatically

This is similar to 650694 but no answer was accepted there, I can't get any of those suggestions to work at all, and I suspect I may be in a slightly different situation. I'm calling log4net.Config.XmlConfigurator.Configure(). But after that point…
Ken
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How do I eliminate duplicate logging in log4net?

I have a program that makes many log4net calls to the "myprogram" loggers. It also calls other code that makes log4net calls to other loggers. I want to capture all logs higher than INFO for "myprogram" and all logs higher than WARN for everything…
Craig Walker
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How to use log4net in Asp.net core 2.0

I configure log4net in my asp.net core 2.0 application as mentioned in this article LINK program.cs public static void Main(string[] args) { var logRepository = LogManager.GetRepository(Assembly.GetEntryAssembly()); …
k11k2
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Log4Net "Could not find schema information" messages

I decided to use log4net as a logger for a new webservice project. Everything is working fine, but I get a lot of messages like the one below, for every log4net tag I am using in my web.config: Could not find schema information for the element…
xsl
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When to use 'nested diagnostic context' (NDC)?

Playing with log4net, I have seen the possibility to use a per-thread stack of context labels called the NDC. The labels pushed on this stack are displayed in a PatternLayout by specifying the %x or the %ndc format parameter. The usage is something…
Cristian Diaconescu
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Is there a way to programmably flush the buffer in log4net

I'm using log4net with AdoNetAppender. It's seems that the AdoNetAppender has a Flush method. Is there anyway I can call that from my code? I'm trying to create an admin page to view all the entries in the database log, and I will like to setup…
Henrik Stenbæk
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VS2005: Assembly '' is incorrectly specified as a file.

I've added a reference to the log4net assembly dll to my project. When I build I get a warning saying: Warning Assembly 'Lib\log4net.dll' is incorrectly specified as a file. I look up the help for this error on MSDN, and it says: This warning…
Ian Boyd
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What would a Log4Net Wrapper class look like?

I have been looking for a logging framework for .net (c#) and decided to give log4net a go after reading up on a few question/answer threads here on stackoverflow. I see people mentioning over and over that they use a wrapper class for log4net and I…
Xerx
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Best way to dynamically set an appender file path

I am trying to find somebody smarter than me to validate some syntax I wrote up. The idea is to configure the filename of my RollingFileAppender to the name of the assembly in order to make it more re-usable for my projects. I've seen this…
Dscoduc
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Have log4net use application config file for configuration data

I would like to store log4net config data in my application.config file. Based on my understanding of the documentation, I did the following: Add a reference to log4net.dll Add the following line in AssemblyInfo.cs: [assembly:…
laconicdev
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