lucene-solr-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Daniel Collins <danwcoll...@gmail.com>
Subject Re: Java 9
Date Tue, 07 Nov 2017 08:46:50 GMT
Oh, blimey, have Oracle gone with Ubuntu-style numbering now? :)

On 7 November 2017 at 08:27, Markus Jelsma <markus.jelsma@openindex.io>
wrote:

> Shawn,
>
> There won't be a Java 10, we'll get Java 18.3 instead. After 9 it is a
> guess when CMS and friends are gone.
>
> Regards,
> Markus
>
>
>
> -----Original message-----
> > From:Shawn Heisey <apache@elyograg.org>
> > Sent: Tuesday 7th November 2017 0:24
> > To: solr-user@lucene.apache.org
> > Subject: Re: Java 9
> >
> > On 11/6/2017 3:07 PM, Petersen, Robert (Contr) wrote:
> > > Anyone else been noticing this this msg when starting up solr with
> java 9? (This is just an FYI and not a real question)
> > >
> > > Java HotSpot(TM) 64-Bit Server VM warning: Option UseConcMarkSweepGC
> was deprecated in version 9.0 and will likely be removed in a future
> release.
> > > Java HotSpot(TM) 64-Bit Server VM warning: Option UseParNewGC was
> deprecated in version 9.0 and will likely be removed in a future release.
> >
> > I have not tried Java 9 yet.
> >
> > Looks like G1 is now the default garbage collector.  I did not know that
> > they were deprecating CMS and ParNew ... that's a little surprising.
> > Solr's default garbage collection tuning uses those two collectors.  It
> > is likely that those choices will be available in all versions of Java
> > 9.  It would be very uncharacteristic for Oracle to take action on
> > removing them until version 10, possibly later.
> >
> > If it were solely up to me, I would adjust Solr's startup script to use
> > the G1 collector by default, eliminating the warnings you're seeing.
> > It's not just up to me though.  Lucene documentation says to NEVER use
> > the G1 collector because they believe it to be unpredictable and have
> > the potential to cause problems.  I personally have never had any issues
> > with it.  There is *one* Lucene issue mentioning problems with G1GC, and
> > that issue is *specific* to the 32-bit JVM, which is not recommended
> > because of the limited amount of memory it can use.
> >
> > My experiments with GC tuning show the G1 collector (now default in Java
> > 9) to have very good characteristics with Solr.  I have a personal page
> > on the Solr wiki that covers those experiments.
> >
> > https://wiki.apache.org/solr/ShawnHeisey
> >
> > Thanks,
> > Shawn
> >
> >
>

Mime
  • Unnamed multipart/alternative (inline, None, 0 bytes)
View raw message