can't kill java process in alpine image

[rubensayshi]

I'm drawing blanks here, we switch from adoptopenjdk/openjdk13:debian to adoptopenjdk/openjdk13:alpine, and I'm unable to kill my java process anymore ...
Both SIGTERM and SIGINT are ignored by the java process, but SIGKILL works, and SIGQUIT also actually gives a thread dump.

to exclude it being some issue with bash vs busybox sh I also installed bash on the alpine image and used that, didn't make any difference...

we do actually have a Runtime.getRuntime()::addShutdownHook registered.

note; also tested with jdk11, just to be sure

[rubensayshi]

this looks mildly related; #98

but it's old ... and I'm not doing exec java ..., I'm doing java ... & and then trying to kill the pid