This is exactly what we did for a clients (alas using Elasticsearch). We then observed better performance through SPM. We used the latest Oracle JVM.
Otis Solr & ElasticSearch Support http://sematext.com/ On Jun 7, 2013 2:55 AM, "Bernd Fehling" <bernd.fehl...@uni-bielefeld.de> wrote: > Hi Shawn, > > I also had CMS with tons of tuning options but still had once in a while > bigger GC pause. After switching to JDK7 I tried G1GC with no other options > and it runs perfekt. > With CMS I saw that old and young generation where growing until they > "had to do" a GC. This produces the sawtooth and also takes longer GC > pause time. > With G1GC the GC is more frequently and better timed, it is softer, more > flexible. > I just removed any old tuning and old GC and have only the G1GC option. > > ulimit -c unlimited > ulimit -l 256 > ulimit -m unlimited > ulimit -n 8192 > ulimit -s unlimited > ulimit -v unlimited > > JAVA_OPTS="-server -d64 -Xmx20g -Xms20g -XX:+UseG1GC > -verbose:gc -XX:+PrintGCDateStamps -XX:+PrintGCDetails -Xloggc:gc.log" > > java version "1.7.0_07" > Java(TM) SE Runtime Environment (build 1.7.0_07-b10) > Java HotSpot(TM) 64-Bit Server VM (build 23.3-b01, mixed mode) > > May be I have just luck with it, but for big heaps it works fine. > > Regards > Bernd > > > Am 06.06.2013 16:23, schrieb Shawn Heisey: > > On 6/6/2013 3:50 AM, Bernd Fehling wrote: > >> What helped me a lot was switching to G1GC. > >> Faster, smoother, very little ripple, nearly no sawtooth. > > > > When I tried G1, it did indeed produce a better looking memory graph, > > but it didn't do anything about my GC pauses. They were several seconds > > with just CMS and NewRatio, and they actually seemed to get slightly > > worse when I tried G1 instead. > > > > To solve the GC pause problem, I've had to switch back to CMS and tack > > on several more tuning options, most of which are CMS-specific. I'm not > > sure how to tune G1. Have you done any additional tuning? > > > > Thanks, > > Shawn > > >
