The reason I ask is because I was chasing down a confusing failure mode while testing druid29 in my company's dev cluster. We compiled with java17 and were having startup of the MM fail saying it can't read class file version 61. In my debugger, I see that the exception is being thrown in Guice ClassReader.java. This is what led me to start wondering about our dependencies and their ability to interface with druid compiled and running with java17. The root cause: I had a monitor class in my monitors list that wasn't supported on MM. • Removing the monitor (CacheMonitor), fixed startup. Just for fun, I also recompiled with a Guice dependency of 5.1.0 which allowed the MM to startup with or without the monitor in the monitors list.

FWIW - I did no validation on anything druid compiled with guice 5.1.0. That might be completely broken. I just did it for fun and to get a data point

not to spam the thread, but had a second to dig a little deeper this morning and see that ClassReader is actually a part of a guice dependency (ASM) which didn't support java17 until v9.1 (guice 4.2.2 depends on ASM v7.0)

Do you have the patch ready for upgrading guice ?

nvm : https://github.com/apache/druid/pull/17578