ASP .Net Core 3.0 - Log4Net MS SQL Server Appender not working

Question

I am currently trying to use Log4Net to insert logs into a MS SQL Server DB. I believe I have Log4Net at least working because I was able to use the FileAppender option/example given Here and I was able to generate a file with the stack traces. However, 8 hours of research and tutorials has me totally stomped on getting the MS SQL Server config examples given Here - same place to work.

I cannot get even their example to work. I created the table, I updated my log4net.config file from the FileAppender option to the provided MS SQL Server option and I fed it the correct connection string settings and... nothing.

I am going to post the code tidbits I believe will be helpful and a photo of proof that my DB table does exist.

---

---

CONFIG FILE

<appender name="AdoNetAppender" type="log4net.Appender.AdoNetAppender">
    <bufferSize value="100" />
    <connectionType value="System.Data.SqlClient.SqlConnection, System.Data, Version=1.0.3300.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" />
    <connectionString value="data source=[].database.windows.net;initial catalog=[];integrated security=false;persist security info=True;User ID=[];Password=[]" />
    <commandText value="INSERT INTO dbo.Log ([Date],[Thread],[Level],[Logger],[Message],[Exception]) VALUES (@log_date, @thread, @log_level, @logger, @message, @exception)" />
    <parameter>
        <parameterName value="@log_date" />
        <dbType value="DateTime" />
        <layout type="log4net.Layout.RawTimeStampLayout" />
    </parameter>
    <parameter>
        <parameterName value="@thread" />
        <dbType value="String" />
        <size value="255" />
        <layout type="log4net.Layout.PatternLayout">
            <conversionPattern value="%thread" />
        </layout>
    </parameter>
    <parameter>
        <parameterName value="@log_level" />
        <dbType value="String" />
        <size value="50" />
        <layout type="log4net.Layout.PatternLayout">
            <conversionPattern value="%level" />
        </layout>
    </parameter>
    <parameter>
        <parameterName value="@logger" />
        <dbType value="String" />
        <size value="255" />
        <layout type="log4net.Layout.PatternLayout">
            <conversionPattern value="%logger" />
        </layout>
    </parameter>
    <parameter>
        <parameterName value="@message" />
        <dbType value="String" />
        <size value="4000" />
        <layout type="log4net.Layout.PatternLayout">
            <conversionPattern value="%message" />
        </layout>
    </parameter>
    <parameter>
        <parameterName value="@exception" />
        <dbType value="String" />
        <size value="2000" />
        <layout type="log4net.Layout.ExceptionLayout" />
    </parameter>
    <root>
        <level value="ALL"></level>
        <appender-ref ref="AdoNetAppender"></appender-ref>
    </root>
</appender>

---

This is a method I made just to make it blow up and to try to log something.

public IActionResult Boom()
{

    // created a boom method just to MAKE it log no matter what.. but no logging happens
    _logger.LogDebug("Testing Debug log");
    throw new Exception("Boom, HA HA HA");
}

---

This is my Program.cs

 public static IHostBuilder CreateHostBuilder(string[] args) =>
        Host.CreateDefaultBuilder(args)
            .ConfigureLogging(logging =>
            {
                logging.AddLog4Net();
            })
            .ConfigureWebHostDefaults(webBuilder =>
            {
              webBuilder.UseStartup<Startup>();
            });
  }

Answer 1

I spend quite a lot of time trying different approaches and here is how I made it work with the least changes required.

First, install NuGet package MicroKnights.Log4NetAdoNetAppender

Then update your log4net.config file to look like this:

<?xml version="1.0" encoding="utf-8" ?>
<log4net>
  <appender name="AdoNetAppender" type="MicroKnights.Logging.AdoNetAppender, MicroKnights.Log4NetAdoNetAppender">
    <bufferSize value="1" />
    <connectionType value="Microsoft.Data.SqlClient.SqlConnection, Microsoft.Data.SqlClient, Version=1.0.0.0,Culture=neutral,PublicKeyToken=23ec7fc2d6eaa4a5"/>
    <connectionStringName value="LocalDB" />
    <connectionStringFile value="appsettings.json" />
    <commandText value="INSERT INTO dbo.Log ([Date],[Thread],[Level],[Logger],[Message],[Exception]) VALUES (@log_date, @thread, @log_level, @logger, @message, @exception)" />
    <parameter>
      <parameterName value="@log_date" />
      <dbType value="DateTime" />
      <layout type="log4net.Layout.RawTimeStampLayout" />
    </parameter>
    <parameter>
      <parameterName value="@thread" />
      <dbType value="String" />
      <size value="255" />
      <layout type="log4net.Layout.PatternLayout">
        <conversionPattern value="%thread" />
      </layout>
    </parameter>
    <parameter>
      <parameterName value="@log_level" />
      <dbType value="String" />
      <size value="50" />
      <layout type="log4net.Layout.PatternLayout">
        <conversionPattern value="%level" />
      </layout>
    </parameter>
    <parameter>
      <parameterName value="@logger" />
      <dbType value="String" />
      <size value="255" />
      <layout type="log4net.Layout.PatternLayout">
        <conversionPattern value="%logger" />
      </layout>
    </parameter>
    <parameter>
      <parameterName value="@message" />
      <dbType value="String" />
      <size value="4000" />
      <layout type="log4net.Layout.PatternLayout">
        <conversionPattern value="%message" />
      </layout>
    </parameter>
    <parameter>
      <parameterName value="@exception" />
      <dbType value="String" />
      <size value="2000" />
      <layout type="log4net.Layout.ExceptionLayout" />
    </parameter>
  </appender>
  <root>
    <level value="Info" />
    <appender-ref ref="AdoNetAppender" />
  </root>
</log4net>

Notice that:

• value of connectionType needs to be like this for .Net Core 3.1+
• connectionStringName points to name of you connection string
• connectionStringFile is a name of your JSON configuration file

So only changes in log4net.config and installing NuGet package are required. After that, you'll get the logs in DB:

For more info, look at the NuGet package GitHub page.