Correct way of using log4net (logger naming)

Regarding how you log messages within code, I would opt for the second approach:

ILog log = LogManager.GetLogger(typeof(Bar));
log.Info("message");

Where messages sent to the log above will be 'named' using the fully-qualifed type Bar, e.g.

MyNamespace.Foo.Bar [INFO] message

The advantage of this approach is that it is the de-facto standard for organising logging, it also allows you to filter your log messages by namespace. For example, you can specify that you want to log INFO level message, but raise the logging level for Bar specifically to DEBUG:

<log4net>
    <!-- appenders go here -->
    <root>
        <level value="INFO" />
        <appender-ref ref="myLogAppender" />
    </root>

    <logger name="MyNamespace.Foo.Bar">
        <level value="DEBUG" />
    </logger>
</log4net>

The ability to filter your logging via name is a powerful feature of log4net, if you simply log all your messages to "myLog", you loose much of this power!

Regarding the EPiServer CMS, you should be able to use the above approach to specify a different logging level for the CMS and your own code.

For further reading, here is a codeproject article I wrote on logging:

• The Art Of Logging

Instead of naming my invoking class, I started using the following:

private static readonly ILog log = LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);

In this way, I can use the same line of code in every class that uses log4net without having to remember to change code when I copy and paste. Alternatively, i could create a logging class, and have every other class inherit from my logging class.

My Answer might be coming late, but I think it can help newbie. You shall not see logs executed unless the changes are made as below.

2 Files have to be changes when you implement Log4net.

---

1. Add Reference of log4net.dll in the project.
2. app.config
3. Class file where you will implement Logs.

Inside [app.config] :

First, under 'configSections', you need to add below piece of code;

<section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler, log4net" />

Then, under 'configuration' block, you need to write below piece of code.(This piece of code is customised as per my need , but it works like charm.)

<log4net debug="true">
    <logger name="log">
      <level value="All"></level>
      <appender-ref ref="RollingLogFileAppender" />
    </logger>

    <appender name="RollingLogFileAppender" type="log4net.Appender.RollingFileAppender">
      <file value="log.txt" />
      <appendToFile value="true" />
      <rollingStyle value="Composite" />
      <maxSizeRollBackups value="1" />
      <maximumFileSize value="1MB" />
      <staticLogFileName value="true" />

      <layout type="log4net.Layout.PatternLayout">
        <conversionPattern value="%date %C.%M [%line] %-5level - %message %newline %exception %newline" />
      </layout>
    </appender>
</log4net>

Inside Calling Class :

Inside the class where you are going to use this log4net, you need to declare below piece of code.

 ILog log = LogManager.GetLogger("log");

Now, you are ready call log wherever you want in that same class. Below is one of the method you can call while doing operations.

log.Error("message");