#Iobserve for windows how to#
#Iobserve for windows windows#

We'll use this to subscribe to 'categories' of events. Now we'll configure a DiagnosticListener to listen for the 'hosting' events, record the name of the event, and write the type of the object we receive.ĭiagnosticListener derives from the abstract DiagnosticSource and is the type you typically interact with, as you'll see.įirst, we need an IObserver implementation. CreateBuilder (args ) WebApplication app = builder.

NET 6 application, created with dotnet new web: WebApplicationBuilder builder = WebApplication. As an example, we'll look at some of the hosting events emitted in. These have very low overhead when not enabled, but allow you to tap into them on demand. The framework libraries in ASP.NET Core emit a large number of diagnostic events. Now we have a vague overview of DiagnosticSource works, let's look at an example of how you you can use it to listen to events in an ASP.NET Core application. There are other logging APIs too, such as the legacy API, and the Windows-only EventLog APIs, but the three listed above are the main ones to think about in modern. There is also an adapter to allow converting DiagnosticSource events to ETW events which can be useful in some cases. The DiagnosticSource infrastructure is very similar to the EventSource infrastructure, but the data being logged does not leave the process, so it does not need to be serialisable. Generally speaking, the ILogger implementation will be the infrastructure you want to use in your applications, so check out the documentation if you are not familiar with it. The infrastructure is generally designed for logging strings, but it allows you to pass objects as additional parameters which can be used for structured logging (such as that provided by SeriLog). You can log to the ILogger infrastructure by injecting an instance of ILogger into your classes, and calling, for example, ILogger.LogInformation(). The ILogger infrastructure is the most commonly used logging ASP.NET Core infrastructure in application code.

#Iobserve for windows windows#

Event Tracing for Windows ( ETW), LTTng on Linux, as well as to EventPipes (generally the prefered approach with modern. Ultimately, EventSource is designed to interface with the underlying operating system's logging infrastructure, e.g. The data that gets logged is strongly typed, but must be serialisable as the data is sent out of the process to be logged.

NET Framework 4.5 era and is used extensively by the framework to instrument itself. DiagnosticSource - Similar in design to EventSource, but does not require the logged data be serialisable.ĮventSource has been available since the.

ILogger - An extensible logging system designed to allow you to plug in additional consumers of logging events.

Designed to interface with OS logging systems.

EventSource - Fast and strongly typed.

There are, broadly speaking, three logging systems in ASP.NET Core: I wrote an introductory blog post looking at DiagnosticSource back in the ASP.NET Core 1.x days, but a lot has changed (and improved) since then! ASP.NET Core logging systems

#Iobserve for windows how to#

In this post I talk a little about the DiagnosticSource infrastructure, how it compares to the other logging infrastructure in ASP.NET Core, and give a brief example of how to use it to listen to framework events.