Csdrhrt

I am working on getting C# applications written for Windows to run on Linux using Mono. I am using Mono 5.18.0.240 from the Mono repository, on Ubuntu 18.04.1.

My understanding is that Mono includes a local file-based event logger. By setting the environment variable MONO_EVENTLOG_TYPE to local (followed by an optional path), events are logged to a file-based log. However, logged events seem to not be sorted into the correct source directory that gets created. This makes it so that all events are logged to the same directory, which makes it more difficult to navigate through the files should many events be logged.

Consider this C# program that just logs two events each for three event sources:

using System;

using System.Diagnostics;



namespace EventLogTest

{

    class Program

    {

        public static void Main()

        {

            var sources = new string { "source1", "source2", "source3" };



            foreach(var source in sources){

                if(! EventLog.SourceExists(source)) EventLog.CreateEventSource(source, "Application");



                EventLog log = new EventLog();

                log.Source = source;



                log.WriteEntry("some event");

                log.WriteEntry("another event");

            }

        }

    }

}

We can build the program into an executable and then run it:

$ csc events.cs

Microsoft (R) Visual C# Compiler version 2.8.2.62916 (2ad4aabc)

Copyright (C) Microsoft Corporation. All rights reserved.

$ MONO_EVENTLOG_TYPE=local:./eventlog mono ./events.exe

The resulting structure of the eventlog directory looks like this:

$ tree ./eventlog

./eventlog

└── Application

    ├── 1.log

    ├── 2.log

    ├── 3.log

    ├── 4.log

    ├── 5.log

    ├── 6.log

    ├── Application

    ├── source1

    ├── source2

    └── source3



5 directories, 6 files

Note that the directories source1, source2, and source3 were created, but the six log files were placed in the top level Application directory instead of the source directories. If we look at the source field of each log file, we can see that the source is correct:

$ grep -a Source ./eventlog/Application/*.log

eventlog/Application/1.log:Source: source1

eventlog/Application/2.log:Source: source1

eventlog/Application/3.log:Source: source2

eventlog/Application/4.log:Source: source2

eventlog/Application/5.log:Source: source3

eventlog/Application/6.log:Source: source3

My expectation is that the above directory structure should look like this instead, considering that each event log source had two events written (and I don't see the point of the second Application directory):

./eventlog

└── Application

    ├── source1

    │   ├── 1.log

    │   └── 2.log

    ├── source2

    │   ├── 1.log

    │   └── 2.log

    └── source3

        ├── 1.log

        └── 2.log

Now, I know that the obvious solution might be to use a logging solution other than Mono's built-in event logging. However, at this point, it is important that I stick with the built-in tools available.

Is there a way to configure Mono's built-in local event logging to save the events to log files in the relevant source directory, or is this possibly a bug in Mono?