Mix Virtual Threads with OS

[liqs02]

Enhancements Request

Use Case

In a microservices architecture, some endpoints perform CPU-intensive tasks like password hashing, while others are I/O-bound. Current Spring configurations do not allow selective threading models for different endpoints, leading to potential inefficiency.

Proposed Enhancement

Introduce some type of annotations to specify threading models at the endpoint level within Spring, enabling a mix of virtual and OS threads based on the operation's nature.

Benefits

• Improved performance through tailored threading.
• Increased flexibility and control

[snicoll]

@liqs02 this has already been requested, please see #31212.