Il sab 21 apr 2018, 06:29 Ismael Juma <ism...@juma.me.uk> ha scritto:

> Hi Enrico,
>
> It is a real problem because it causes indexes to take a lot more disk
> space upfront. The sparsity is an important if people over partition, for
> example.
>

Got it.
In production I saw no issue, maybe due to much availability of disk space.

Should I file a JIRA or you will do?
Enrico


> Ismael
>
> On Fri, Apr 20, 2018 at 12:41 PM, Enrico Olivelli <eolive...@gmail.com>
> wrote:
>
> > Il ven 20 apr 2018, 20:24 Ismael Juma <ism...@juma.me.uk> ha scritto:
> >
> > > Hi Enrico,
> > >
> > > Coincidentally, I saw your message to nio-dev and followed up there.
> > >
> >
> > I think this is not a 'real' problem, you will notice the difference only
> > if you have a lot of empty topics/partitions.
> > In fact when you simply upgrade to jdk9/10 immediately you are charged
> with
> > 10MB of disk space for each partition.
> > In production I did not suffer this change because usually you do not
> have
> > empty partitions.
> > In my test environments, where I had thousands of test empty partitions,
> > disks filled up immediately and without any reason, it took time to
> > understand the real cause. Broker will crash without much 'log' as disk
> is
> > out of space.
> >
> > Maybe it would be useful to add some notice about this potential problem
> > during the upgrade of the jdk.
> >
> > Hope that helps
> > Enrico
> >
> >
> > > Ismael
> > >
> > > On Fri, Apr 20, 2018 at 8:18 AM, Enrico Olivelli <eolive...@gmail.com>
> > > wrote:
> > >
> > > > It is a deliberate change in JDK code
> > > >
> > > > Just for reference see this discussion  on nio-dev list on OpenJDK
> > > >
> http://mail.openjdk.java.net/pipermail/nio-dev/2018-April/005008.html
> > > >
> > > >
> > > > see
> > > > https://bugs.openjdk.java.net/browse/JDK-8168628
> > > >
> > > > Cheers
> > > > Enrico
> > > >
> > > >
> > > >
> > > > 2018-03-05 14:29 GMT+01:00 Enrico Olivelli <eolive...@gmail.com>:
> > > >
> > > > > Workaround:
> > > > > as these brokers are only for test environments I have set very
> small
> > > > > values for index file size, which affects pre-allocation
> > > > > segment.index.bytes=65536
> > > > > log.index.size.max.bytes=65536
> > > > >
> > > > > If anyone has some thought it will be very appreciated
> > > > > Cheers
> > > > >
> > > > > Enrico
> > > > >
> > > > >
> > > > > 2018-03-05 13:21 GMT+01:00 Enrico Olivelli <eolive...@gmail.com>:
> > > > >
> > > > >> The only fact I have found is that with Java8 Kafka is creating
> > > "SPARSE"
> > > > >> files and with Java9 this is not true anymore
> > > > >>
> > > > >> Enrico
> > > > >>
> > > > >> 2018-03-05 12:44 GMT+01:00 Enrico Olivelli <eolive...@gmail.com>:
> > > > >>
> > > > >>> Hi,
> > > > >>> This is a very strage case. I have a Kafka broker (part of a
> > cluster
> > > of
> > > > >>> 3 brokers) which cannot start upgrading Java from Oracle JDK8 to
> > > > Oracle JDK
> > > > >>> 9.0.4.
> > > > >>>
> > > > >>> There are a lot of .index and .timeindex files taking 10MB, they
> > are
> > > > for
> > > > >>> empty partiions.
> > > > >>>
> > > > >>> Running with Java 9 the server seems to rebuild these files and
> > each
> > > > >>> file takes "really" 10MB.
> > > > >>> The sum of all the files (calculated using du -sh) is 22GB and
> the
> > > > >>> broker crashes during startup, disk becomes full and no log more
> is
> > > > >>> written. (I can send an extraction of the logs, but the tell only
> > > > about
> > > > >>> 'rebuilding index', the same as on Java 8)
> > > > >>>
> > > > >>> Reverting the same broker to Java 8 and removing the index files,
> > the
> > > > >>> broker rebuilds such files, each files take 10MB, but the full
> sum
> > of
> > > > sizes
> > > > >>> (calculated using du -sh) is 38 MB !
> > > > >>>
> > > > >>> I am running this broker on CentosOS 7 on EXT4 FS.
> > > > >>>
> > > > >>> I have upgraded the broker to latest and greatest Kafka 1.0.0
> (from
> > > > >>> 0.10.2) without any success.
> > > > >>>
> > > > >>> All of the other testing clusters on CentOS7 (same SO settings)
> did
> > > not
> > > > >>> have any problem.
> > > > >>>
> > > > >>> The broker is given 4GB or RAM and 4G of Max Direct Memory Size
> (on
> > > > >>> Java8 it works fine with 1GB and default max direct memory size)
> > > > >>>
> > > > >>> Which are the relevant configuration options ?
> > > > >>>
> > > > >>> Thoughts ?
> > > > >>>
> > > > >>> Thank you
> > > > >>>
> > > > >>> Enrico
> > > > >>>
> > > > >>>
> > > > >>>
> > > > >>>
> > > > >>
> > > > >
> > > >
> > >
> > --
> >
> >
> > -- Enrico Olivelli
> >
>
-- 


-- Enrico Olivelli

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