> Is there any place you have in mind where you are eager leverage Java 21 language features?
This will allow for things like green (virtual) threads and JDK 25 will allow for things like FFI, which will help move along the goals mentioned in: https://github.com/apache/druid/issues/19039. > Regarding java25, is that your analysis from initial inspection the Hadoop docs/code or did you smoke check the compatibility at runtime too? I've run JDK 25 on JDK 21-compiled bytecode internally on a test cluster and have validated it passes CI. I believe the prior blockers for running JDK 25 were the incompatibilities with SecurityManager brought in by older versions of Hadoop. On Tue, Apr 14, 2026 at 7:47 AM Lucas Capistrant <[email protected]> wrote: > Thanks for starting the thread, Jesse. I think this is a great idea for > Druid 38. Is there any place you have in mind where you are eager leverage > Java 21 language features? A good motivation to share with the change > notice helps communicate the benefit of updating our Java support matrix. > Regardless, I’m on board with it. > > Regarding java25, is that your analysis from initial inspection the Hadoop > docs/code or did you smoke check the compatibility at runtime too? > > Thanks, > Lucas > > On Tue, Apr 14, 2026 at 12:08 AM Jesse Tuğlu <[email protected]> wrote: > > > Hi folks, > > > > Wanted to start a devlist thread to discuss removal of JDK 17 in favor of > > JDK 21/25 as supported runtimes in Druid 38. The PR for this change is > > here: https://github.com/apache/druid/pull/19304. Upgrading to Hadoop > 3.5 > > clients enabled <https://hadoop.apache.org/docs/r3.5.0/> the use of JDK > 21 > > and, from what I can tell, contains SecurityManager patches that unblock > > Druid's usage of JDK 25. > > > > Best, > > > > Jesse > > >
