Consider using Java >= 21 to allow usage of virtual threads

[eivanov89]

Hi,

We did a fork of benchbase to get TPC-C for YDB. Here we describe our testing setup and TPC-C implementation with a particular focus on the threading model.

We need to run 15K TPC-C warehouses and even more, which requires >= 150,000 terminals. Currently, you use the model where 1 terminal equals 1 thread, which is not optimal. Even with sleeping threads, it's hard to create more than 3-5K terminals per server. As of Java 21, virtual threads are available, and they are in many ways similar to goroutines. Transitioning to virtual threads involves straightforward code changes here. However, there might be some potential deadlocks depending on the particular JDBC driver and benchmark. For instance, when we added the c3p0 session manager, we encountered a deadlock. It was holding carrier threads waiting for sessions to become available, while session threads were parked for I/O and couldn't get carrier threads to perform I/O.

Is there any chance you would consider switching to Java 21 so that virtual threads become an option?

[bpkroth]

Hi, happy to accept a PR (even partial to get started with) if you have one. Thanks!

[eivanov89]

Hi Brian, I've created the pull request. The changes are straightforward. Looking forward the review.