Not being well versed in the capabilities of the virtual threads. However, both the Servlet and the JAX-RS models are "thread agnostic" in that while we "know" we're running on a thread, the API doesn't expose it directly.

So, if something like Tomcat "simply" switch its internal threading model from the current model to the virtual model, would the applications know any different? Could you drag and drop a JAX-RS service or a Java Servlet into a container running on virtual threads, or would rapidly run into some leaky wall?

Seems like a virtual thread model of Tomcat would be quite useful in some scenarios.