To Cache or Not to Cache Virtual Threads

The official guidance on virtual threads is clear: Virtual threads are cheap and plentiful, and thus should never be pooled: A new virtual thread should be created for every application task. — Ron Pressler & Alan Bateman, JEP 444: Virtual Threads Creating a virtual thread is cheap — have millions, and don’t pool them! — Ron Pressler, State of Loom As part of our work on improving Quarkus performance with virtual threads and investigating Loom’s scheduling behavior , we decided to test this advice with data.