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 > >
