Merge pull request #2604 from Kielek/splunk-otel-dotnet-1.9.0-log4net

Splunk OTel .NET 1.9.0 - log4net

Author: aurbiztondo-splunk

gdi/get-data-in/application/otel-dotnet/instrumentation/connect-traces-logs.rst

@@ -7,7 +7,11 @@ Connect .NET trace data with logs using OpenTelemetry instrumentation
 .. meta::
    :description: Automatic correlation between logs and traces provided by the Splunk Distribution of OpenTelemetry .NET.
 
-The Splunk Distribution of OpenTelemetry .NET automatically exports logs enriched with tracing context from any application that uses logging API from :new-page:`Microsoft.Extensions.Logging <https://www.nuget.org/packages/Microsoft.Extensions.Logging>` for logging.
+The Splunk Distribution of OpenTelemetry .NET automatically exports logs enriched with tracing context from any application that uses logging API from:
+
+* :new-page:`Microsoft.Extensions.Logging <https://www.nuget.org/packages/Microsoft.Extensions.Logging>`
+* :new-page:`log4net <https://www.nuget.org/packages/log4net>`
+
 
 Application logs are enriched with tracing metadata and then exported to a local instance of the OpenTelemetry Collector in ``OTLP`` format.
 
@@ -48,9 +52,13 @@ The following is an example of logs produced by a sample console application:
 Check compatibility and requirements
 ====================================================
 
-.. note:: Automatic log to trace correlation only works for .NET applications. For .NET Framework use manual correlation. See :ref:`manual-trace-logs-correlation-otel`.
+.. note:: Automatic log to trace correlation for ``Microsoft.Extensions.Logging`` only works for .NET applications. For .NET Framework use manual correlation. See :ref:`manual-trace-logs-correlation-otel`.
 
-``Microsoft.Extensions.Logging`` version ``9.0.0`` and higher are supported.
+The following applies:
+
+* ``Microsoft.Extensions.Logging`` version ``9.0.0`` and higher are supported
+* ``log4net`` version from ``2.0.13`` to ``4.0.0`` are supported
+* The environmental variable ``OTEL_DOTNET_AUTO_LOGS_ENABLE_LOG4NET_BRIDGE`` needs to be set to ``true``
 
 .. _dotnet-otel-enable-log-correlation:
 
@@ -92,10 +100,31 @@ Additionally, the instrumentation adds the following attributes:
 Manual log to trace correlation
 ===================================================
 
-You can configure logging libraries to include tracing attributes in logs written to existing logs destination.
+You can configure logging libraries to include tracing attributes in logs written to existing log destinations.
+
+``log4net``
+-----------------------------------------------
+
+You can modify ``conversionPattern`` in your log4net appender to include tracing attributes in logs written to existing log destinations. 
+
+The following properties are set by default for the collection of logging events:
+
+* `trace_id`
+* `span_id`
+* `trace_flags`
+
+Example on how to configure ``ConsoleAppender``:
+
+.. code-block:: text
+
+   <appender name="ConsoleAppender" type="log4net.Appender.ConsoleAppender">
+      <layout type="log4net.Layout.PatternLayout">
+         <conversionPattern value="%date [%thread] %-5level %logger - %message span_id=%property{span_id} trace_id=%property{trace_id} trace_flags=%property{trace_flags} test_key=%property{test_key}%newline" />
+      </layout>
+   </appender>
 
 ``NLog``
-----------------------------------------------------
+-----------------------------------------------
 
 You can use :new-page:`NLog.DiagnosticSource <https://www.nuget.org/packages/NLog.DiagnosticSource>`. See the :new-page:`NLog official documentation <https://github.com/NLog/NLog.DiagnosticSource>` for more information.
 

gdi/get-data-in/application/otel-dotnet/instrumentation/manual-dotnet-instrumentation.rst

@@ -23,7 +23,7 @@ To create custom spans and traces, follow these steps:
 
    .. code:: xml
 
-      <PackageReference Include="System.Diagnostics.DiagnosticSource" Version="8.0.0" />
+      <PackageReference Include="System.Diagnostics.DiagnosticSource" Version="9.0.0" />
 
 3. Create an ``ActivitySource`` instance:
 
@@ -56,7 +56,7 @@ To create custom metrics, follow these steps:
 
    .. code:: xml
 
-      <PackageReference Include="System.Diagnostics.DiagnosticSource" Version="8.0.0" />
+      <PackageReference Include="System.Diagnostics.DiagnosticSource" Version="9.0.0" />
 
 2. Create a ``Meter`` instance: