Hello, I met next problem during configuration Tomcat web server.
Server is run on unix box with next JVM and GC flags:
-Xms4096m -Xmx4096m -XX:MaxPermSize=512m
-server -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode
-XX:+CMSIncrementalPacing -XX:CMSIncrementalDutyCycleMin=1
-XX:CMSIncrementalDutyCycle=5 -XX:+UseParNewGC
-XX:+CMSPermGenSweepingEnabled -XX:+CMSClassUnloadingEnabled
-XX:MaxGCPauseMillis=50 -XX:MaxGCMinorPauseMillis=50 -XX:+DisableExplicitGC
I have quite high request load for server 3000 qps.
Server box specification: 2 cpu with (2 core each), 8 GB of RAM.
And I'm seeing very strange java process behaviour:
RAM usage don't exceed 1,5 Gb of RAM, BUT virtual mem is growing right now it is 7,6 GB. But it was upto 10 GB (I restarted server after that).
Do you have any ideas why java works so strange?