[hibernate-dev] Bad boot performance since 5.4 switched to ByteBuddy

Sanne Grinovero sanne at hibernate.org
Wed Aug 5 06:20:36 EDT 2020 

 > Does anyone know if there is a known performance issue [...]

I'm aware that loading Byte Buddy takes a little longer than Javassist
to initialize: it's a larger library and it needs to load a
significantly larger number of classes, including ASM, but this comes
with several benefits so as long as the cost is not disproportionate,
I wouldn't see it as a performance issue.

How bad is it in absolute numbers? Is the highlighted problem specific
to a particular bootstrap configuration, such as a particular
container or a particular way of booting it? Lots of entities, or very
few of them?

Also, are you concerned about "cold boot" as in bootstrapping a new
JVM+Hibernate, or about (re)starting an ORM instance in a running JVM?

+1 to Guillaume's suggestions: if you can point a finger to a specific
problematic area we might be able to do something about it.

Tangentially: having to currently support both ByteBuddy and Javassist
complicates things quite a bit, and complications also come at a
performance cost. I wish to fully remove Javassist in 6 - for other
reasons as well - and I believe that doing so will allow us to improve
some integration with BB.
But it would be interesting to know more about this problem, so to
make sure we go into the right direction.

Thanks

On Tue, 4 Aug 2020 at 19:15, Guillaume Smet <guillaume.smet at gmail.com> wrote:
>
> If you can get some SVG profiles from Async Profiler, that would help to
> determine what we can do to improve things.
>
> And yes, we don't want the BB state to be static again. We had a hard time
> avoiding the static here and I don't remember exactly why but it was for
> sure worth it or I wouldn't have spent time on it :).
>
> --
> Guillaume
>
> On Tue, Aug 4, 2020 at 6:28 PM Yoann Rodiere <yoann at hibernate.org> wrote:
>
> > > @Yoann: It seems the commit you posted is about supporting a
> > > SecurityManager environment, but I'm not sure how making the state an
> > > instance variable rather than static helps with this. What kind of
> > > buggyness are you referring to?
> >
> > Not sure what the bug was; I just remember there was a problem (multiple
> > problems?) related to the bytebuddy state being static. Maybe the bytebuddy
> > state does change from one execution to the other, depending on the
> > classpath, security manager, or whatever. Maybe it was just a problem when
> > running tests and changing some classes from one test to another, or
> > changing the security manager. To be honest I don't remember. Maybe @Guillaume
> > Smet <guillaume.smet at gmail.com> remembers, but that was two years ago...
> >
> > Yoann Rodière
> > Hibernate Team
> > yoann at hibernate.org
> >
> >
> > On Tue, 4 Aug 2020 at 18:17, Christian Beikov <christian.beikov at gmail.com>
> > wrote:
> >
> >> Hey,
> >>
> >> sorry for the confusion. "Apparently" was the wrong word I guess, my
> >> colleague Moritz Becker ran a few CPU sampling rounds with JFR which is
> >> how we found out about this, so this is more like "the data suggests"
> >> that the problem is in ByteBuddy.
> >>
> >> I can do some profiling with the async-profiler as well, but I the issue
> >> definitely is the proxy building code.
> >>
> >> @Yoann: It seems the commit you posted is about supporting a
> >> SecurityManager environment, but I'm not sure how making the state an
> >> instance variable rather than static helps with this. What kind of
> >> buggyness are you referring to?
> >>
> >> Am 04.08.2020 um 17:56 schrieb Guillaume Smet:
> >> > Hi Christian,
> >> >
> >> > I don't like "apparently" when talking about performances :).
> >> >
> >> > I would advise to use async profiler
> >> > (https://github.com/jvm-profiling-tools/async-profiler, also see
> >> > https://github.com/quarkusio/quarkus/blob/master/TROUBLESHOOTING.md to
> >> > learn more on how to use it) to try to understand what's going wrong
> >> > and how we could improve things.
> >> >
> >> > I remember things were very slow with the initial ByteBuddy
> >> > implementation Rafael did and we got much better results by caching
> >> > the ByteBuddy transformations. In particular the calls to the
> >> > ByteBuddy DSL are quite expensive in terms of allocations because they
> >> > are creating a ton of objects.
> >> >
> >> > Once we have some profiling results, we can talk.
> >> >
> >> > --
> >> > Guillaume
> >> >
> >> > On Tue, Aug 4, 2020 at 5:26 PM Christian Beikov
> >> > <christian.beikov at gmail.com <mailto:christian.beikov at gmail.com>> wrote:
> >> >
> >> >     I'm moving this discussion from Zulip to the mailing list as
> >> >     Rafael does
> >> >     not seem to be on Zulip. Here a little context:
> >> >
> >> >      > Does anyone know if there is a known performance issue with
> >> >     Bytebuddy
> >> >     during boot in 5.4? I noticed that 5.4 takes about 25%, sometimes
> >> >     up to
> >> >     30% percent longer to boot, even when using a prebuilt Jandex index,
> >> >     apparently due to the use of Bytebuddy
> >> >
> >> >      > @Moritz Becker found the issue while trying to find out why our
> >> >     Blaze-Persistence testsuite runs into CI timeouts with 5.4 but not
> >> >     with 5.3
> >> >
> >> >      > So AFAIK, the PojoEntityTuplizer builds the proxy class through
> >> >     org.hibernate.proxy.pojo.bytebuddy.ByteBuddyProxyHelper#buildProxy
> >> >     which
> >> >     takes significantly longer than the javassist implementation
> >> >
> >> >     I haven't tried it yet, but it seems to me that making the
> >> >     byteBuddyState in
> >> >     org.hibernate.bytecode.internal.bytebuddy.BytecodeProviderImpl
> >> static
> >> >     might help. I'd guess this will help with the test execution time
> >> for
> >> >     the Hibernate testsuite as well.
> >> >
> >> >     Any idea how to improve this @Rafael ?
> >> >
> >> >     Regards,
> >> >
> >> >     Christian
> >> >
> >> >     _______________________________________________
> >> >     hibernate-dev mailing list
> >> >     hibernate-dev at lists.jboss.org <mailto:hibernate-dev at lists.jboss.org
> >> >
> >> >     https://lists.jboss.org/mailman/listinfo/hibernate-dev
> >> >
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> >
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