Explain the difference between in-process and out-of-process hosting.

Question

ICSM Computer · Answer

In ASP.NET Core, in-process and out-of-process refer to how your application is hosted and run with respect to the web server (like IIS or Kestrel). Here's a clear breakdown: In-Process Hosting The ASP.NET Core app runs inside the IIS worker process (w3wp.exe).No separate process for the Kestrel server is created.Better performance due to avoiding reverse proxy overhead. Configuration: In your .csproj file: Request Flow: Pros: Faster because there is no inter-process communication.Simpler setup – everything runs in a single process. Cons: Runs only on Windows with IIS.Limited to IIS features and constraints. Out-of-Process Hosting ASP.NET Core app runs in its own process (like dotnet.exe).IIS (or Nginx/Apache) acts as a reverse proxy forwarding requests to the app. Configuration: In your .csproj file: Request Flow: Pros: Cross-platform (Linux, macOS, Windows).Full control over Kestrel and app lifetime. Cons: Slight performance penalty due to the proxy hop.More configuration complexity (especially on Linux). Comparison Table Feature In-Process Out-of-Process Process w3wp.exe (IIS worker) Separate dotnet.exe Performance Faster Slightly slower OS Support Windows only Cross-platform Reverse Proxy Needed No Yes (IIS, Nginx, Apache) Hosting Model Tag InProcess OutOfProcess When to Use Which? Use In-Process for Windows + IIS deployments where performance matters.Use Out-of-Process if you: Need cross-platform supportWant more control over the app processAre using Kestrel behind a reverse proxy

Feature	In-Process	Out-of-Process
Process	`w3wp.exe` (IIS worker)	Separate `dotnet.exe`
Performance	Faster	Slightly slower
OS Support	Windows only	Cross-platform
Reverse Proxy Needed	No	Yes (IIS, Nginx, Apache)
Hosting Model Tag	`InProcess`	`OutOfProcess`

forum

Explain the difference between in-process and out-of-process hosting.

Can you answer this question?

1 Answers

In-Process Hosting

Configuration:

Request Flow:

Pros:

Cons:

Out-of-Process Hosting

Configuration:

Request Flow:

Pros:

Cons:

Comparison Table

When to Use Which?