Additional Stacktrace info when serializing log4net properties to Json - json

Question

I'm attempting to serialize my logs to Json. I'm using log4net with a custom layout, but when an exception is logged, I get the following malformed JSON (Note the additional stacktrace info at the end)
Am I missing a setting for log4net, or is this a serialization issue?
UPDATE: This has to be something with log4net, because json.net serializes an Exception perfectly.
***UPDATE (FIXED): Updated code below.
{
"UserSessionId":"4b146c92-fe99-4f78-bbef-720df2cf7473",
"ProcessSessionId":1,
...
"Logger":"testharness.Program","ThreadName":"1",
"ExceptionObject":{
"ClassName":"System.ApplicationException",
"Message":"Test Exception Logging",
"Data":null,
"InnerException":null,
"HelpURL":null,
"StackTraceString":" at testharness.Program.Main(String[] args) in C:\\temp\\testharness\\Program.cs:line 18",
"RemoteStackTraceString":null,
...
"WatsonBuckets":null
},
...
"log4net:HostName":"ol-4RBNMH2"
}}
System.ApplicationException: Test Exception Logging
at testharness.Program.Main(String[] args) in C:\temp\testharness\Program.cs:line 18
log4net configuratiton
<log4net>
<appender name="RollingFileCompositeAppender" type="log4net.Appender.RollingFileAppender">
<file value="c:\\logs\\testharness.txt"/>
<appendToFile value="true"/>
<rollingStyle value="Composite"/>
<datePattern value="yyyy-MM-dd"/>
<maxSizeRollBackups value="-1"/>
<maximumFileSize value="1MB"/>
<countDirection value="1"/>
<preserveLogFileNameExtension value="false"/>
<staticLogFileName value="false"/>
<layout type="Company.log4net.JsonLayout"></layout>
</appender>
<root>
<level value="ALL"/>
<appender-ref ref="RollingFileCompositeAppender"/>
</root>
</log4net>
The Custom Layout class
public class JsonLayout : LayoutSkeleton
{
public JsonLayout() {
IgnoresException = false;
}
...
/// <inheritdoc />
public override void ActivateOptions()
{
}
/// <inheritdoc />
public override void Format(TextWriter writer, LoggingEvent loggingEvent)
{
_customProperties.PhysicalMemory = Process.GetCurrentProcess().WorkingSet64;
var evt = new CustomLoggingEvent(loggingEvent, _customProperties);
writer.Write(JsonConvert.SerializeObject(evt));
}
}
[JsonObject(MemberSerialization.OptIn)]
public class CustomLoggingEvent
{
...
[JsonProperty]
public Exception ExceptionObject { get; set; }
[JsonProperty]
public long PhysicalMemory { get; set; }
[JsonProperty]
public PropertiesDictionary Properties { get; set; }
}
The Test Harness:
internal class Program
{
private static void Main()
{
Console.WriteLine($"{typeof(JsonLayout)}");
var log = log4net.LogManager.GetLogger(typeof(Program));
try
{
log.Debug("hello again world");
throw new ApplicationException("Test Exception Logging");
}
catch (Exception e)
{
log.Error("Exception Thrown", e);
}
Console.ReadLine();
}
}

Answer 1

I downloaded the log4net source and found the issue. When creating a custom layout implementing LayoutSkeleton, if your layout handles the LoggingEvent.ExceptionObject, then the IgnoresException property should be set to false; the default value is true. I updated the code in the question with a constructor wherein the IgnoresException property is set to true. I probably should have waited a day while I researched, but maybe this will help someone else.