JVM warnings during Java 11 startup

[Ivan Pavlukhin]

It uses Instrumentation API. I am not aware how to access it outside of agent.

пн, 4 мар. 2019 г. в 01:17, Dmitriy Pavlov <[hidden email]>:

>
> Looks promising. Is it possible to run this code from main? Or it has to be
> an agent.
>
> вс, 3 мар. 2019 г., 20:26 Павлухин Иван <[hidden email]>:
>
> > I did an exercise setting up a project which uses maven dependency to
> > ignite-core module. And it seems that it is not practical to simply
> > add dependency section to pom, instruction is needed to avoid
> > surprises.
> >
> > Also I succeed in creating a java agent which effectively allows to
> > access all packages of other modules [1]. It is really a hack, but
> > perhaps it can be useful. To be honest I adopted a sample found in the
> > Internet [2] because it is outdated.
> >
> > [1] https://gist.github.com/pavlukhin/7e6740504af099cc86d67c976f1e9bee
> > [2] https://gist.github.com/raphw/91c81b8afdfd76ccfd87508a0af0e8bb
> >
> > вс, 3 мар. 2019 г. в 09:01, Павлухин Иван <[hidden email]>:
> > >
> > > Dmitriy,
> > >
> > > Thank you for details. Yes it looks really troublesome to start Ignite
> > > development with Java 9+. I am not happy to say that but even more
> > > hacky workarounds could help us. In short term.
> > >
> > > I will try to do an exercise of setting up development environment
> > > from scratch to feel the real situation.
> > >
> > > сб, 2 мар. 2019 г. в 20:39, Dmitriy Pavlov <[hidden email]>:
> > > >
> > > > In a standalone mode user have to specify options. He or she may use
> > > > application templates to simplify launch just like
> > > >
> > https://github.com/apache/ignite/tree/master/examples#running-examples-on-jdk-91011
> > > > but
> > > > it is anyway required.
> > > >
> > > > As a user in the past (and currently) I may say: Ignite-based (or any
> > other
> > > > grid-based) soft is often developed in IDEA in the same process with
> > server
> > > > nodes. Ignite.sh (or another grid node launcher) is used in prod, but
> > not
> > > > for dev.
> > > >
> > > > сб, 2 мар. 2019 г. в 10:01, Павлухин Иван <[hidden email]>:
> > > >
> > > > > Dmitriy,
> > > > >
> > > > > I am a little bit confused by statement that "user should specify
> > > > > options". I thought that we can setup all needed variables in our
> > > > > startup scripts. Or are you talking about library case?
> > > > >
> > > > > And answering the question. Yes, more options will be needed.
> > > > > --add-exports makes not exported packages from some module visible to
> > > > > other specified modules.
> > > > > --add-opens allows reflective access to non-public members in other
> > > > > module packages (they call it "deep reflection").
> > > > >
> > > > > Of course we should check everything carefully during implementation.
> > > > >
> > > > > пт, 1 мар. 2019 г. в 22:26, Dmitriy Pavlov <[hidden email]>:
> > > > > >
> > > > > > Would it require a user to specify more options or use longer
> > parameter
> > > > > > values if we change from -add-exports to -add-opens?
> > > > > >
> > > > > > Stanislav, could you prepare PR to demonstrate the idea. PR will
> > probably
> > > > > > answer to all questions.
> > > > > >
> > > > > > пт, 1 мар. 2019 г. в 15:09, Павлухин Иван <[hidden email]>:
> > > > > >
> > > > > > > Dmitriy,
> > > > > > >
> > > > > > > > Would add opens require user to set up a longer line?
> > > > > > >
> > > > > > > I am not sure that got that question right. Could you please
> > elaborate?
> > > > > > >
> > > > > > > пт, 1 мар. 2019 г. в 09:39, Dmitriy Pavlov <[hidden email]>:
> > > > > > > >
> > > > > > > > Would add opens require user to set up a longer line?
> > > > > > > >
> > > > > > > > пт, 1 мар. 2019 г., 9:01 Павлухин Иван <[hidden email]>:
> > > > > > > >
> > > > > > > > > By the way. It is interesting that Unsafe class is not the
> > source
> > > > > of
> > > > > > > > > warnings. I checked (with java 10) that there is no warnings
> > issued
> > > > > > > > > when Unsafe instance is accessed with good old reflective
> > way.
> > > > > > > > >
> > > > > > > > > пт, 1 мар. 2019 г. в 08:05, Павлухин Иван <
> > [hidden email]>:
> > > > > > > > > >
> > > > > > > > > > Here is how our friends from Hazelcast tackle the problem
> > [1].
> > > > > Using
> > > > > > > > > > --add-opens as Stan proposed looks like a good option in
> > short
> > > > > > > > > > perspective. By the way to determine all illegally accessed
> > > > > packages
> > > > > > > > > > we can use --illegal-access=warn, which does not deny
> > operation
> > > > > but
> > > > > > > > > > only prints a warning. I guess we can found the majority of
> > > > > packages
> > > > > > > > > > by analyzing TC logs.
> > > > > > > > > >
> > > > > > > > > > WDYT?
> > > > > > > > > >
> > > > > > > > > > [1]
> > > > > > > > >
> > > > > > >
> > > > >
> > https://gist.githubusercontent.com/pavlukhin/c8c7c6266eeab56048c31f5cdfb31d20/raw/1988aa92075eb2a60328e28b3a5933a7c7cbc347/hz-java9.png
> > > > > > > > > >
> > > > > > > > > > пт, 1 мар. 2019 г. в 03:04, Denis Magda <[hidden email]
> > >:
> > > > > > > > > > >
> > > > > > > > > > > Flags/hacks is not a way to go for serious and mature
> > projects
> > > > > like
> > > > > > > > > Ignite.
> > > > > > > > > > > We should switch to another mode - how to replace Unsafe
> > > > > > > completely.
> > > > > > > > > > >
> > > > > > > > > > > -
> > > > > > > > > > > Denis
> > > > > > > > > > >
> > > > > > > > > > >
> > > > > > > > > > > On Thu, Feb 28, 2019 at 4:32 AM Dmitriy Pavlov <
> > > > > [hidden email]
> > > > > > > >
> > > > > > > > > wrote:
> > > > > > > > > > >
> > > > > > > > > > > > > may become unavailable in any time.
> > > > > > > > > > > >
> > > > > > > > > > > > I remember this was discussed in 2013 that Unsafe will
> > be
> > > > > removed
> > > > > > > > > soon. But
> > > > > > > > > > > > nothing is changed yet, so I hope unsafe will be
> > available
> > > > > for a
> > > > > > > > > long time
> > > > > > > > > > > > (with flags/hacks/etc).
> > > > > > > > > > > >
> > > > > > > > > > > >
> > > > > > > > > > > > чт, 28 февр. 2019 г. в 09:11, Petr Ivanov <
> > > > > [hidden email]>:
> > > > > > > > > > > >
> > > > > > > > > > > > > According to warning message, there are no options
> > at all,
> > > > > as
> > > > > > > > > Unsafe may
> > > > > > > > > > > > > become unavailable in any time.
> > > > > > > > > > > > >
> > > > > > > > > > > > >
> > > > > > > > > > > > > > On 27 Feb 2019, at 22:53, Denis Magda <
> > [hidden email]
> > > > > >
> > > > > > > wrote:
> > > > > > > > > > > > > >
> > > > > > > > > > > > > > It's fine as long as the project can be launched.
> > I would
> > > > > > > better
> > > > > > > > > start
> > > > > > > > > > > > > > looking for Unsafe alternatives as the next step.
> > We
> > > > > can't
> > > > > > > live
> > > > > > > > > with it
> > > > > > > > > > > > > > forever, the time to phase it out has come :)
> > > > > > > > > > > > > >
> > > > > > > > > > > > > > -
> > > > > > > > > > > > > > Denis
> > > > > > > > > > > > > >
> > > > > > > > > > > > > >
> > > > > > > > > > > > > > On Wed, Feb 27, 2019 at 9:53 AM Dmitriy Pavlov <
> > > > > > > > > [hidden email]>
> > > > > > > > > > > > > wrote:
> > > > > > > > > > > > > >
> > > > > > > > > > > > > >> Sure, we could try this option.
> > > > > > > > > > > > > >>
> > > > > > > > > > > > > >> ср, 27 февр. 2019 г. в 19:16, Ilya Kasnacheev <
> > > > > > > > > > > > > [hidden email]>:
> > > > > > > > > > > > > >>
> > > > > > > > > > > > > >>> Hello!
> > > > > > > > > > > > > >>>
> > > > > > > > > > > > > >>> I wonder if we could try to redirect output to
> > null,
> > > > > > > initialize
> > > > > > > > > > > > > >> GridUnsafe
> > > > > > > > > > > > > >>> and then bring output back :)
> > > > > > > > > > > > > >>>
> > > > > > > > > > > > > >>> Regards,
> > > > > > > > > > > > > >>> --
> > > > > > > > > > > > > >>> Ilya Kasnacheev
> > > > > > > > > > > > > >>>
> > > > > > > > > > > > > >>>
> > > > > > > > > > > > > >>> ср, 27 февр. 2019 г. в 18:30, Dmitriy Pavlov <
> > > > > > > > > [hidden email]>:
> > > > > > > > > > > > > >>>
> > > > > > > > > > > > > >>>> Hi Ignite Developers,
> > > > > > > > > > > > > >>>>
> > > > > > > > > > > > > >>>> During the start of Ignite node under Java 11
> > > > > (actually
> > > > > > > 9+) or
> > > > > > > > > > > > during
> > > > > > > > > > > > > >>> local
> > > > > > > > > > > > > >>>> development you may face with warning related to
> > > > > illegal
> > > > > > > > > access.
> > > > > > > > > > > > > >>>>
> > > > > > > > > > > > > >>>> You know that Ignite uses Unsafe operation for
> > durable
> > > > > > > memory.
> > > > > > > > > > > > > >>>>
> > > > > > > > > > > > > >>>> Accessing to Unsafe requires
> > --illegal-access=permit
> > > > > (Now
> > > > > > > it
> > > > > > > > > is the
> > > > > > > > > > > > > >>> default
> > > > > > > > > > > > > >>>> for JVM. From the doc:
> > > > > > > > > > > > > >>>> permit: ... The first reflective-access
> > operation to
> > > > > any
> > > > > > > such
> > > > > > > > > > > > package
> > > > > > > > > > > > > >>>> causes a warning to be issued. However, no
> > warnings
> > > > > are
> > > > > > > > > issued after
> > > > > > > > > > > > > >> the
> > > > > > > > > > > > > >>>> first occurrence. This single warning describes
> > how to
> > > > > > > enable
> > > > > > > > > > > > further
> > > > > > > > > > > > > >>>> warnings.
> > > > > > > > > > > > > >>>>
> > > > > > > > > > > > > >>>> Warning example:
> > > > > > > > > > > > > >>>>
> > > > > > > > > > > > > >>>> WARNING: An illegal reflective access operation
> > has
> > > > > > > occurred
> > > > > > > > > > > > > >>>> WARNING: Illegal reflective access by
> > > > > > > > > > > > > >>>> org.apache.ignite.internal.util.GridUnsafe$2
> > > > > > > > > > > > > >>>> (file:..libs/ignite-core-2.7.0.jar) to field
> > > > > > > > > java.nio.Buffer.address
> > > > > > > > > > > > > >>>> WARNING: Please consider reporting this to the
> > > > > > > maintainers of
> > > > > > > > > > > > > >>>> org.apache.ignite.internal.util.GridUnsafe$2
> > > > > > > > > > > > > >>>> WARNING: Use --illegal-access=warn to enable
> > warnings
> > > > > of
> > > > > > > > > further
> > > > > > > > > > > > > >>>> illegal reflective access operations
> > > > > > > > > > > > > >>>> WARNING: All illegal access operations will be
> > denied
> > > > > in a
> > > > > > > > > future
> > > > > > > > > > > > > >> release
> > > > > > > > > > > > > >>>>
> > > > > > > > > > > > > >>>>
> > > > > > > > > > > > > >>>> Unfortunately removing or disabling this
> > warning is
> > > > > > > absolutely
> > > > > > > > > > > > > >>> impossible,
> > > > > > > > > > > > > >>>> it is generated by JVM and there is no option to
> > > > > disable
> > > > > > > it:
> > > > > > > > > > > > > >>>>
> > > > > > > > > > > > > >>>>
> > > > > > > > > > > > > >>>
> > > > > > > > > > > > > >>
> > > > > > > > > > > > >
> > > > > > > > > > > >
> > > > > > > > >
> > > > > > >
> > > > >
> > https://docs.oracle.com/en/java/javase/11/tools/java.html#GUID-3B1CE181-CD30-4178-9602-230B800D4FAE
> > > > > > > > > > > > > >>>>
> > > > > > > > > > > > > >>>>
> > > > > > > > > > > > > >>>> Sincerely,
> > > > > > > > > > > > > >>>> Dmitriy Pavlov
> > > > > > > > > > > > > >>>>
> > > > > > > > > > > > > >>>
> > > > > > > > > > > > > >>
> > > > > > > > > > > > >
> > > > > > > > > > > > >
> > > > > > > > > > > >
> > > > > > > > > >
> > > > > > > > > >
> > > > > > > > > >
> > > > > > > > > > --
> > > > > > > > > > Best regards,
> > > > > > > > > > Ivan Pavlukhin
> > > > > > > > >
> > > > > > > > >
> > > > > > > > >
> > > > > > > > > --
> > > > > > > > > Best regards,
> > > > > > > > > Ivan Pavlukhin
> > > > > > > > >
> > > > > > >
> > > > > > >
> > > > > > >
> > > > > > > --
> > > > > > > Best regards,
> > > > > > > Ivan Pavlukhin
> > > > > > >
> > > > >
> > > > >
> > > > >
> > > > > --
> > > > > Best regards,
> > > > > Ivan Pavlukhin
> > > > >
> > >
> > >
> > >
> > > --
> > > Best regards,
> > > Ivan Pavlukhin
> >
> >
> >
> > --
> > Best regards,
> > Ivan Pavlukhin
> >

--
Best regards,
Ivan Pavlukhin