Recently, I came across the following site: High-performance Logging with LoggerMessage in ASP.NET Core.

It says that the logging using LoggerMessage.Define style is a high-performance logging pattern because of:

1. boxing of arguments when using extension methods
2. repetitive message template parsing

Fair enough, so I decided to do a benchmark comparing LoggerMessage vs Logger extension method vs. string.Format logging.

I decided to do it because after checking the code:

1. boxing of the value types in LoggerMessage.Define style is happening anyway , just later, inside the class LogValues (see the method ToArray ).

2. The same is for the message template parsing (see Microsoft.Extensions.Logging.Internal.LogValuesFormatter.Format method).

The benchmark sample

In the sample for the benchmark I setup logging infrastructure without actually writing the messages anywhere. I wanted to measure just the overhead of the different logging style.

The results are:

As you can see, LoggerMessage style of logging is really faster then logging via extension methods but the difference is really small and the code change is quite significant. I saw a discussion that the team wanted to migrate the code base to LoggerMessage style because it's high performant logging. I wouldn't invest in it for already running project.

At the end of the day, LoggerMessage looks promising, especially if the parsing the Message Template without boxing would be really implemented. I thought the LoggerMessage.Define parses the message template and generate a custom method on the fly for creating the result message.

What do you think?