Creating snapshots with dynamically loaded JARs

[Nikola Grcevski]

Yes, I think it would be super useful when debugging problems of why a
path wasn't marked as "persistent". An INFO log message would be
awesome.

Thanks,
Nikola

On Wed, Dec 7, 2022 at 11:46 AM Anton Kozlov <akozlov at azul.com> wrote:
>
> On 12/5/22 19:48, Nikola Grcevski wrote:
> > It's actually our bug :), which I ported to the simple example, the
> > Files.list() stream is never closed. Sorry for the noise.
>
>
> Thanks for the example to play with. So after closing the stream for Files.list(), the dynamically loaded jar is marked "persistent" and the checkpoint is successful, right? It may be a bit of a problem that the checkpoint implicitly catches everything an application may open. Would it be useful to print all persistent jars, like [1]
>
> Dec 07, 2022 6:32:21 PM jdk.internal.util.jar.PersistentJarFile beforeCheckpoint
> INFO: Assuming persistent /home/anton/Downloads/openjdk_CRaC_simplemodule/./lib/ansi-console/jansi-2.4.0.jar
> Dec 07, 2022 6:32:21 PM jdk.internal.util.jar.PersistentJarFile beforeCheckpoint
> INFO: Assuming persistent /home/anton/Downloads/openjdk_CRaC_simplemodule/./lib/ansi-console/elasticsearch-ansi-console-8.7.0-SNAPSHOT.jar
> Dec 07, 2022 6:32:21 PM jdk.internal.util.jar.PersistentJarFile beforeCheckpoint
> INFO: Assuming persistent /home/anton/Downloads/openjdk_CRaC_simplemodule/target/simplemodule.jar
> CR: Checkpoint ...
> Killed
>
> I'm not a big fan of persistent files, but while they are there, some additional information should at least make assumptions that got into the image more visible.
>
> [1] https://github.com/AntonKozlov/crac/commit/492fb87e8371529750701969604a863cacadf724
>
> Thanks,
> Anton