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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Does the Log4j security violation vulnerability affect log4net?

I have recently read about the zero-day issue in Log4J. I work with a few applications, written with .NET, that use the log4net logging library, which is based on Log4j. Does log4net have any similar security vulnerabilities as the CVE-2021-44228…
FooAnon
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How do I insert tabs in the log4net layout pattern?

My need is simple - I want to be able to open my text log file in excel, so that it automatically breaks it in columns matching the log fields. For that, I need the log fields separated with a tab. My pattern is: %utcdate [%thread] %-5level %logger…
mark
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How do you configure and enable log4net for a stand-alone class library assembly?

Background I am writing a class library assembly in C# .NET 3.5 which is used for integration with other applications including third-party Commercial-Off-The-Shelf (COTS) tools. Therefore, sometimes this class library will be called by applications…
Zach Burlingame
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Why are all my log4net levels false?

I'm using log4net in my ASP.NET MVC3 project, but all logging properties such as IsDebugEnabled == false In my AssemblyInfo I have: [assembly: XmlConfigurator(Watch = true)] In my log class I have public Log4NetLogger() { …
John Smith
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Log4Net: Logging in 2 byte languages (japanese, chinese etc.)

I would like to log data to a file in 2 byte languages (chinese, japanese etc) using log4net. How to properly configure log4net to do that?
nakhli
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Crystal Reports error when deployed..Could not load file or assembly 'log4net

Please help. I have a web application that was built in VS2010 and we are using the CR plugin for 2010 and everything works perfect on our local machines. When we go to deploy the web application to Server 2008 the application runs fine until we…
EvanGWatkins
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log4net process id information

I am trying to create a logging solution that involves multiple processes on multiple machines. I planned on using the UDPAppender to send all log messages to a single machine that would manage them. I have a few questions about patternstrings vs…
teleball
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How do I create an asynchronous wrapper for log4net?

By default, log4net is a synchronous logging mechanism, and I was wondering if there was a way to have asynchronous logging with log4net?
Jonathan Beerhalter
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Windows Event Viewer and log4net

I have idea to write errors from my application to the Windows Event Viewer using log4net. Can I do it or not? And if I can, how :). Thank you.
jitm
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How do I configure log4net so that log.IsDebugEnabled is true?

I am trying to use log4net in an ASP.NET application with Visual Studio 2005. I have declared an instance of the logger like so: Private Shared ReadOnly log As ILog = LogManager.GetLogger("") I am trying to use it in the following manner: If…
Ryan Taylor
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Is it possible to wildcard logger names in log4net configuration?

In my application, I use log4net, with all types creating their own logger based on their type - e.g. : private static readonly ILog Log = LogManager.GetLogger(typeof(Program)); As I am developing, I leave the root logger on DEBUG so as to catch…
Rob Levine
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How to configure or setup Log4Net with ASP.NET ( included MVC) C# on Visual Studio 2012 ~ ~

I want to record software process logs to files. Rather than make my own log system, I am trying to use Log4Net with ASP.NET MVC, but I have run into problems setting it up in Visual Studio 2015, like: How to setup web.config / Global.asax…
Willie Cheng
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Log4Net and .NET 4.0

There have not been any log4net release for some time. This has not presented any problems with 3.5, but what about .NET 4? Has anyone heard any rumblings about a release to support the version 4 framework when it comes out?
Bobbie
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How to use Property Injection with AutoFac?

In a Console application, I'm using Log4Net and in the Main method I'm getting the logger object. Now, I'd like to make this log object available in all my classes by letting all the classes inherit from a BaseClass which has a ILog property and is…
The Light
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log4net log all unhandled application errors

Can you point me to some tutorial or samples on how I can log all un-handled exceptions that are occurring on my mvc web app using log4net. Thank you
kaivalya
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