Yes, I would recommend to go to Java 8 and give it a shot with G1 and report back :)
Sent from my iPhone > On Nov 28, 2017, at 3:30 PM, Sharanya Santhanam <ssanthan....@gmail.com> > wrote: > > HI Johannes , > > We are running on Java version jdk1.7.0_67 . We are using > ConcurrentMarkAndSweep. Would you recommend using G1GC ? > > > These are our current settings > > -XX:NewRatio=8 -XX:+UseParNewGC -XX:-UseGCOverheadLimit -XX:PermSize=256m > -Xloggc:<> -XX:HeapDumpPath=oom -XX:+PrintGCDetails -XX:+PrintGCDateStamps > -XX:ErrorFile=<log>/oom/hs2jvmerror%p.log -XX:+UseGCLogFileRotation > -XX:NumberOfGCLogFiles=5 -XX:GCLogFileSize=128M -XX:+CMSClassUnloadingEnabled > -XX:+CMSPermGenSweepingEnabled -XX:+HeapDumpOnOutOfMemoryError > -XX:+UseConcMarkSweepGC -XX:+CMSParallelRemarkEnabled -XX:MaxPermSize=1024m > -Xmx69427m -Xms128m -XX:MaxHeapFreeRatio=30 -XX:MinHeapFreeRatio=10 > -XX:+UseParNewGC -XX:-UseGCOverheadLimit -XX:PermSize=256m > > > Thanks , > Sharanya > >> On Tue, Nov 28, 2017 at 2:19 PM, Johannes Alberti <johan...@altiscale.com> >> wrote: >> Hi Sharanya, >> >> Can you share your current GC settings and Java version. Are you using Java >> 8/9 w/ G1 already? >> >> Regards, >> >> Johannes >> >> Sent from my iPhone >> >>> On Nov 28, 2017, at 12:57 PM, Sharanya Santhanam <ssanthan....@gmail.com> >>> wrote: >>> >>> Hello , >>> >>> I am currently trying to upgrade hive version on our prod clusters form >>> V1.2 to v2.1 >>> We also want to adopt HS2 on the new upgraded cluster. Earlier all queries >>> were submitted via Hive cli. >>> >>> Would like to understand how large a single HS2 Heap size can be ? And is >>> there any formula to figure out the how many concurrent sessions I can >>> support with this particular heap setting? >>> >>> >>> We currently have a upper limit of supporting 300 concurrent sessions ( >>> hive.server2.thrift.max.worker.threads=300). Based on this we set the max >>> heap size to 70 GB , but seeing many long GC pauses. >>> >>> >>> Would like to understand what is the industry standard for max HS2 Heap >>> size. Are there any recommendations on what JMV GC setting work best for >>> supporting such high number of concurrent sessions? >>> >>> Thanks, >>> Sharanya >
