[hibernate-dev] Cache region names are not prefixed in 5.3
Radim Vansa
rvansa at redhat.com
Fri May 18 03:02:15 EDT 2018
On 05/18/2018 02:54 AM, Gail Badner wrote:
>
>
> On Thu, May 17, 2018 at 5:24 PM, Gail Badner <gbadner at redhat.com
> <mailto:gbadner at redhat.com>> wrote:
>
> I see that HHH-11356 removed prefixes from region names used by
> Hibernate.
>
> I also noticed that entity regions are unprefixed and the package
> name is removed.
>
>
> Actually, the package names are being included in the region names.
> The test I was looking at did not have a package.
>
>
> I've created 2 issues:
> HHH-12599 to add Javadoc to make it clear that region names are
> unprefixed;
> HHH-12598 to add the package onto entity region names.
>
>
> I've rejected HHH-12598.
>
>
> Should I create an ISPN issue for hibernate-infinispan (or
> whatever it's referred to now) to add the prefixes?
>
I take it as confirmed that RegionFactory is supposed to do this.
Created https://issues.jboss.org/browse/ISPN-9174
R.
>
> On Thu, May 17, 2018 at 4:55 AM, Sanne Grinovero
> <sanne at hibernate.org <mailto:sanne at hibernate.org>> wrote:
>
> On 17 May 2018 at 12:09, Radim Vansa <rvansa at redhat.com
> <mailto:rvansa at redhat.com>> wrote:
> > I basically agree with Sanne here that having the prefix
> isolated opens
> > space for performance improvements, though if certain call
> is prefixed,
> > RegionFactory can always drop that prefix. The important
> thing is to mention
> > if the region name is prefixed or not in javadocs. I would
> also prefer if
> > *all* region names that RegionFactory is supposed to access
> followed the
> > same strategy (prefixed/not-prefixed).
> >
> > 5.1 included method
> >
> > QueryResultsRegion buildQueryResultsRegion(String
> regionName, Properties
> > properties)
> >
> > where StandardQueryCache did the prefix for us, the change
> in 5.3 to
> >
> > QueryResultsRegion buildQueryResultsRegion(String
> regionName,
> > SessionFactoryImplementor sessionFactory)
> >
> > does not indicate that the prefix won't be there and the
> javadoc is missing
> > completely.
> >
> > Also, DomainDataRegionConfig.getRegionName() has no javadoc and
> > RegionFactory does not add the prefix.
> >
> > @Steve could you please amend the javadoc and confirm if RF
> should prefix
> > region names?
> >
> > @Sanne while cache manager per deployment is an obvious way
> to distinguish
> > regions at deployments, CM holds some heavy resources (e.g.
> threads) - so I
> > while we are supposed to scale number of caches up to
> thousands (and we've
> > fixed some problems that arise when you have for example ~3k
> caches), ATM
> > you're not supposed to scale CMs. And I don't think that
> we'll focus in this
> > direction since the bright future lies in microservices :)
>
> Right, good points. It's a possible optimization I'd like to see
> eventually but it's not trivial to get there yet.
>
> Yet assuming a microservices scenario, this does become trivial to
> benefit from: the container knows there's a single deployment, a
> single CM. So no need to isolate them at all, just need to
> possibly
> isolate multiple PUs defined in the same service.
>
> So it will be easy to run hundreds of isolated microservices
> on the
> same physical CPU and kill each other via process contention :P
>
> >
> > Radim
> >
> >
> > On 05/17/2018 12:23 PM, Sanne Grinovero wrote:
> >>
> >> On 17 May 2018 at 11:11, Sanne Grinovero
> <sanne at hibernate.org <mailto:sanne at hibernate.org>> wrote:
> >>>
> >>> I think this is the RegionFactory's responsibility, as
> Hibernate ORM
> >>> alone can't know if this is necessary.
> >>>
> >>> Prefixing is one of many options to isolate caches; a
> Cache technology
> >>> might wish to use a different approach by implementing a
> custom
> >>> `org.hibernate.cache.spi.CacheKeysFactory`.
> >>
> >> Hum, I regret how I wrote the above paragraph.
> >>
> >> I actually meant that a Cache technology could implement
> isolation in
> >> many different ways.
> >> Using a custom `CacheKeysFactory` is just an example, there
> are many
> >> other options as well. In fact, I believe a good choice for
> >> application servers would be to have an independent
> CacheManager for
> >> each deployment. Then it can safely inspect the deployment,
> see if
> >> there are multiple Persistence Units using the same caching
> >> technology, and implement further isolation only if necessary.
> >>
> >> These thoughts are a consequence of a chat I had with Paul
> Ferraro
> >> from the WildFly team, as he mentioned the size of the keys
> becoming
> >> problematic with all the additional prefixing they need to
> apply. I
> >> hope this will make it possible to e.g. create an "as small as
> >> possible" unique identifier for the deployments to replace the
> >> deployment name during serialization (to identify the
> CacheManager)
> >> followed by a numeric id indexing the PUs within the
> deployment - or
> >> nothing altogether in case of single PUs.
> >>
> >> Of course, I don't expect that to be needed right away; the
> >> RegionFactory could just do good old prefixing for now but
> I hope
> >> we'll explore such improvements in the near future.
> >>
> >> Thanks,
> >> Sanne
> >>
> >>> Not least the server / deployer might be able to hint the
> Cache
> >>> provider to tell if isolation is at all necessary.
> >>>
> >>> In conclusion, by having Hibernate ORM not messing with
> prefixes
> >>> allows other technologies to implement more efficient
> solutions. Our
> >>> own code also ends up being more efficient by not needing
> to add a
> >>> prefix during each and every access to the cache.
> >>>
> >>> Thanks,
> >>> Sanne
> >>>
> >>> On 17 May 2018 at 06:34, Gail Badner <gbadner at redhat.com
> <mailto:gbadner at redhat.com>> wrote:
> >>>>
> >>>> I see that cache region names are not being prefixed in 5.3.
> >>>>
> >>>> EnabledCaching sets the TimestampsRegion region name
> >>>> to TimestampsRegion.class.getName(), and sets the
> QueryResultsRegion
> >>>> region
> >>>> name to QueryResultsRegion.class.getName(). [1]
> >>>>
> >>>> Without a prefix, WildFly is failing intermittently when
> there are 2
> >>>> persistence units with the query cache enabled due to:
> >>>>
> >>>> org.infinispan.commons.CacheConfigurationException:
> ISPN000453: Attempt
> >>>> to
> >>>> define configuration for cache
> org.hibernate.cache.spi.TimestampsRegion
> >>>> which already exists
> >>>>
> >>>> Entity region names are not being prefixed either.
> >>>>
> >>>> Should they be prefixed by Hibernate or by the RegionFactory?
> >>>>
> >>>> Regards,
> >>>> Gail
> >>>>
> >>>> [1]
> >>>>
> >>>>
> https://github.com/hibernate/hibernate-orm/blob/master/hibernate-core/src/main/java/org/hibernate/cache/internal/EnabledCaching.java#L80-L92
> <https://github.com/hibernate/hibernate-orm/blob/master/hibernate-core/src/main/java/org/hibernate/cache/internal/EnabledCaching.java#L80-L92>
> >>>> _______________________________________________
> >>>> 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
> <https://lists.jboss.org/mailman/listinfo/hibernate-dev>
> >
> >
> >
> > --
> > Radim Vansa <rvansa at redhat.com <mailto:rvansa at redhat.com>>
> > JBoss Performance Team
> >
>
>
>
--
Radim Vansa <rvansa at redhat.com>
JBoss Performance Team
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