jpro.onJVMShutdown - shutdown hook from jpro.conf never gets called

[hw-hass23]

The JVM shutdown hook of jpro.onJVMShutdown, configured in jpro.conf, never gets called. The configured class doesn't event get loaded.
JPro does process the JVM shutdown properly, from
May 11, 2026 11:23:52 PM io.helidon.Main shutdown
INFO: Shutdown requested by JVM shutting down
down to
May 11, 2026 11:23:52 PM io.helidon.Main shutdown
INFO: Shutdown finished
when triggered either from my IDE or with System.exit from within the application. So the JPro shutdown mechanism seems to work, but it does not honor jpro.onJVMShutdown.
Maven jpro:stop is worse - this plainly kills the JVM without any shutdown sequence being run.

Expected behavior:
Upon proper JVM exit (no hard kill), JPro shutdown will load and execute the class configuried with jpro.onJVMShutdown, waiting for its main function to return before finally allowing the JVM to terminate.

Actual behavior:
JPro/Helidon shutdown commences in parallel with other JVM shutdown hooks registered via Runtime.getRuntime().addShutdownHook(...), but kills the JVM before those other shutdown hooks have completed their work.
This is very bad behavior as my application is not able to properly store overall server side application state.

My jpro.conf setup is identical to https://github.com/JPro-one/JPro-Samples/blob/main/logging/src/main/resources/jpro.conf, even with the otherwise undocumented "jpro.forceShutdown = false".
The jpro.onJVMStartup and jpro.onFXStartup work just fine - those classes get instantiated and their main methods called.

INFO: OS: Windows 11
INFO: JPro: 2026.1.1
INFO: Java version: 25.0.2
INFO: JVM: 25.0.2 Azul Systems, Inc.

[FlorianKirmaier]

Thank you for reporting this, we will take a look.

[FlorianKirmaier]

First, i can confirm that the mechanism is broken. We will provide a solution soon.
The state is the following:
jpro.onJVMShutdown just doesn't get called. Probably a regression which happened when we switched the internal webserver.

The stop-script often have a timeout of n-seconds - which usually is helpful because many JVMs get stuck.
The jpro.forceShutdown should be removed or redesigned to something like "forceShutdownAfter = 30" - to configure how much time it will give the shutdown-sequence. With -1 as a possible value to disable this feature. And of course than it should be documented.
(Stop-Script, maven gradle still can forcekill after some time)

[FlorianKirmaier]

Update:

Can you test whether everything works with 2026.2.1-RC2?

jpro.forceShutdown = 5 is now the default - the value changed from boolean to integer and will be documented in the next release. The number represents how many seconds it takes until JVM tries for force-shutdown. It can be disabled with -1.

On Windows, the SoftKill should work now in most cases.
There is now a automated regression test to ensure the graceful shutdown works on all Operating Systems.

[hw-hass23]

May 19, 2026 2:18:51 AM com.jpro.internal.server.JProInitializer$
INFO: JPro: 2026.2.1-RC2

I can confirm that jpro.forceShutdown now behaves differently.

jpro.onJVMShutdown on the other hand still is not called. Here is the JUL output after a System.exit(0). I see some activities of JPro, and Java shutdoen hooks are called. But I am missing the Helidon shutdown output from 2026.1.1. And my configured shutdown class neither gets instantiated nor called.

May 19, 2026 2:31:54 AM java.lang.Shutdown logRuntimeExit
FINE: Runtime.exit() called with status: 0
java.lang.Throwable: Runtime.exit(0)
at java.base/java.lang.Shutdown.logRuntimeExit(Shutdown.java:179)
at java.base/java.lang.Shutdown.exit(Shutdown.java:160)
at java.base/java.lang.Runtime.exit(Runtime.java:177)
at java.base/java.lang.System.exit(System.java:1540)
at my.code.jpro.ui.impl.WindowManager.performBackendExit(WindowManager.java:87)
at com.sun.javafx.application.PlatformImpl.lambda$runLater$0(PlatformImpl.java:425)
at com.sun.glass.ui.monocle.RunnableProcessor.runLoop(RunnableProcessor.java:92)
at com.sun.glass.ui.monocle.RunnableProcessor.run(RunnableProcessor.java:51)
at java.base/java.lang.Thread.run(Thread.java:1474)

May 19, 2026 2:31:54 AM com.jpro.internal.server.JProInitializer$
INFO: [JPro] -> Server stopped: {running_time: 36.563s, instances_count: 1, views_count: 1, os_name: Windows 11, jpro_version: 2026.2.1-RC2, reason: jvm-shutdown}
May 19, 2026 2:31:54 AM com.jpro.activity
INFO: Closing the server -> used memory: 268 MB - free system memory: 2052 MB
May 19, 2026 2:31:54 AM io.helidon.webserver.ServerListener listen
INFO: [0x224cf805] @default socket closed.
Deleted pid file: C:\Users\hw_ms\Devel\PicardZulu\RUNNING_PID