Hi developers,
These day I meet a strange problem and I can’t find why
When I start a spark thrift server with spark.driver.memory 64g, then use jdk8/bin/jinfo pid to see vm flags got below information,
In 64g vm, UseCompressedOops should be closed by default, why spark thrift server is -XX: +UseCompressedOops
Non-default VM flags: -XX:CICompilerCount=15 -XX:-CMSClassUnloadingEnabled -XX:CMSFullGCsBeforeCompaction=0 -XX:CMSInitiatingOccupancyFraction=75 -XX:+CMSParallelRemarkEnabled -XX:-ClassUnloading -XX:+DisableExplicitGC -XX:ErrorFile=null -XX:-ExplicitGCInvokesConcurrentAndUnloadsClasses -XX:InitialHeapSize=2116026368 -XX:+ManagementServer -XX:MaxDirectMemorySize=8589934592 -XX:MaxHeapSize=6442450944 -XX:MaxNewSize=2147483648 -XX:MaxTenuringThreshold=6 -XX:MinHeapDeltaBytes=196608 -XX:NewSize=705298432 -XX:OldPLABSize=16 -XX:OldSize=1410727936 -XX:+PrintGC -XX:+PrintGCDateStamps -XX:+PrintGCDetails -XX:+PrintGCTimeStamps -XX:+PrintTenuringDistribution -XX:-TraceClassUnloading -XX:+UseCMSCompactAtFullCollection -XX:+UseCMSInitiatingOccupancyOnly -XX:+UseCompressedClassPointers -XX:+UseCompressedOops -XX:+UseConcMarkSweepGC -XX:+UseFastUnorderedTimeStamps -XX:+UseParNewGC
Command line: -Xmx6g -Djava.library.path=/home/hadoop/hadoop/lib/native -Djavax.security.auth.useSubjectCredsOnly=false -Dcom.sun.management.jmxremote.port=9021 -Dcom.sun.management.jmxremote.authenticate=false -Dcom.sun.management.jmxremote.ssl=false -XX:MaxPermSize=1024m -XX:PermSize=256m -XX:MaxDirectMemorySize=8192m -XX:-TraceClassUnloading -XX:+UseCompressedOops -XX:+UseParNewGC -XX:+UseConcMarkSweepGC -XX:+CMSClassUnloadingEnabled -XX:+UseCMSCompactAtFullCollection -XX:CMSFullGCsBeforeCompaction=0 -XX:+CMSParallelRemarkEnabled -XX:+DisableExplicitGC -XX:+PrintTenuringDistribution -XX:+UseCMSInitiatingOccupancyOnly -XX:CMSInitiatingOccupancyFraction=75 -Xnoclassgc -XX:+PrintGCDetails -XX:+PrintGCDateStamps Since I am not a professor in VM, hope for some help
