Chris, Great post earlier today! This is a super interesting topic to me.
You can find the performance testing results located here: http://ec2-18-188-185-212.us-east-2.compute.amazonaws.com:8080/web-report/ I did 10 runs with 1000 threads with a ramp up time of 3 seconds for a duration of 200 seconds. Ignore the 11th run. This is a really simple REST application with Spring. It just makes an insert into a MySQL table. When I get a moment I will put my code into GitHub, but again, there is not much to it. You can find a very similar Spring Boot example with embedded Tomcat here: https://medium.com/@anil.java.story/embracing-virtual-threads-in-spring-boot-4140d3b8a5a But he uses JDK 20 with --enable-preview turned on. The mistake I think I made was that the inserts are not really blocking because they happen so quickly. Maybe because I did not put enough load in the test? I have no synchronized blocks in my code. So, it appeared to me that the inserts were taking twice the amount of time with virtual threads. I think that extra time is just overhead of pinning virtual threads to a platform thread and managing the ForkJoinPool. What is going to happen is that people are going to “flip the switch”…useVirtualThreads=”true”. They will find that performance will not be as good as using an operating system thread and abandon virtual threads because their code does not block. So, I need to come up with an example where my code blocks and redo the perf test and prove this out. I don’t know. Regards, William Crowell This e-mail may contain information that is privileged or confidential. If you are not the intended recipient, please delete the e-mail and any attachments and notify us immediately.
