NLog on is popular logging component for .NET applications. I am using it in one project where I built multi-threaded server that is running similar threads with different configuration. As those thread are independent services I needed way how to configure NLog to create different log file for each thread. Here is my solution.

When new service starts in its thread I will configure NLog in code to create log file to correct folder with correct name and layout. Image on right shows how server is keeping instances data on disk. Each instance has its own folder and for logs there is subfolder because for every date there will be new log file.

var target = new FileTarget();
target.Name = InstanceName;
target.FileName = LogsFolder + "/${shortdate}.log";
target.Layout = "${date:format=HH\\:MM\\:ss} ${logger} ${message}";
 
var config = new LoggingConfiguration();
config.AddTarget(this.Name, target);
 
var rule = new LoggingRule("*", LogLevel.Info, target);
config.LoggingRules.Add(rule);
 
LogManager.Configuration = config;
 
_logger = LogManager.GetLogger(InstanceName);
_logger.Info("Logger is initialized");

This way I got all logging done on code level and as there is arbitrarily small probability that logging ever changes I am very sure that this seemingly temporary solution will live with project for long time.