Logging Unique Request IDs in text file NLog - To differentiate between requests

Question

I am using NLog logging mechanism in my application. The problem I face is when concurrent requests hit the application logging is done asynchronously and I am not able to identify which line belongs to which request. Is there a way in NLog to set the configuration to NLog itself logging a unique Request ID for each request ?

<?xml version="1.0" encoding="utf-8" ?>
<nlog xmlns="http://www.nlog-project.org/schemas/NLog.xsd"           xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">  
<targets>    
<!-- add your targets here -->
<target xsi:type="File" name="file"    fileName="E:\IBELogs\AirAvailability\AirAvailability.log" layout="${longdate}        ${uppercase:${level}} ${message}" />    
</targets>
<rules>
<!-- add your logging rules here --> 
<logger name="*" minlevel="Trace" writeTo="file" />    
</rules>
</nlog>

Answer 1

In NLog 4.1 ${activityid} was introduced, see here. I cannot say MSDN documentation is clear enough about its value, but so far, this is doing the trick for us, since every request in our webAPI application gets assigned a unique GUID and it is preserved through the entire request as we see the same value in several Nlog operations in the same request.