For the last month we've been focusing quite a bit of energy toward seeing what it will take for WildFly to run well on the upcoming JDK 17. This post is the second of two I plan. The first was an attempt to start a discussion around a couple topics; this one will be more of a status update.
Status summary is things are progressing well, no show-stoppers so far, but plenty more to do.
WF 23 runs well on SE 13. We want to get to 17. Issues we've faced include:
1) SE 14 dropped the java.security.acl package.
2) SE 15 introduced hidden classes (JEP 371)
3) SE 16 strongly encapsulated JDK internals by default (JEP 396) (see  for a nice primer)
4) Some components (i.e. ones to bytecode manipulation) have static maximum SE versions they support, requiring upgrades to versions that support 17.
The big problem with 1) is the remaining use of Picketbox. Work continues on eliminating any requirement to use PB. Before standard WildFly can support SE 17 we'll need to change our standard configs to not require PB. Work on that is in progress and needs to accelerate this summer as we work on WF 25.
Meanwhile a lot of our testing focus is on WF Preview, which already doesn't require use of PB. Our testing of WF Preview already runs over 5,000 tests, so we can identify a lot of issues by running it. We've set up 3 nightly test jobs to run test WF Preview using SE 15, 16, and 17. We can also run the EE 9.1 TCK against WF Preview, resulting in over 75K tests being run.
Following yesterday's WF Core upgrade, results are looking pretty decent -- 111 failures out of over 5200 tests on , with the bulk of those brand new (so hopefully something crept in yesterday that's easily fixed) and a number of others with known causes that are being worked.
The JEP 396 change (issue 3 above) is the main subject of my other post. I'll just say here that Richard Opalka did a lot of research which resulted in  and , a set of VM launch settings that allow WF to run reasonably on SE 16+. Those came into master yesterday.
Having those in means we run well enough that analyzing results from running the EE 9.1 TCk with SE 17 starts to be worthwhile. A run last night showed 305 failures in the platform and standalone jaxb TCKs (out of over 71K tests), with explanations / likely solutions available for at least 100 of those. So pretty good.