Re: Deadlock in Java9.getDefaultImportClasses() ?

On 08.04.24 16:48, Mutter, Florian wrote:
> After updating Kubernetes from 1.27 to 1.28 one of our applications is
> not working anymore.
>
> The application uses thymeleaf templating engine that uses groove under
> the hood. The application does not respond to request that require a
> template to be rendered. Looking at the stacktrace did not give us any
> hint what is causing this. In the profiler it looks like a lot of time
> is spent waiting in Java9.getDefaultImportClasses() method. We could not
> find any code in there or in ClassFinder.find() that looks like it could
> cause a dead lock.
>
> When attaching the debugger and adding some break points in
> Java9.getDefaultImportClasses() it did work 🤷‍♂️.

This is really weird. Java, Groovy and thymeleaf versions are the same?
What Groovy version are you using btw? What version of Java?


> The only thing that we could see that is different between a working
> setup and a non-working one is the updated Kubernetes with updated node
> images using a newer linux kernel. No idea how this could impact the code.

The linux kernel should not impact that unless it is a bug in Java.

> Does anyone have an idea what could cause this or what we could do to
> identify the cause of the dead lock?
>
> I attached a screenshot of the profiler.

I would be nice to know the line number, then we know at least which of
the 3 possible supplyAsync().get() fails. I was thinking maybe this can
happen if there is an exception... but normally get() should produce an
ExecutionException in that case.

Right now I am a bit clueless

bye Jochen