UseParallelGC on OTM webserver

[Kristof Stevens]

Hi,

We moved the Parallel GC into PROD but please check the JVM behaviour. Is this a normal behaviour?? Our Tomcat JVM is running now on 2 GC threads, and it seems the JVM is doing Full GC all the time (every 2 minutes) with up to 10 secs of "stop the worlds". When using paralle GC, does this mean you also have a freeze of the UI during a Full GC? Without Parallel GC, JVM was doing a Full GC every 20-30 minutes, freezes of 20 secs.

We are using following setting in PROD :

# Java Additional Parameters
wrapper.java.additional.1=-server
wrapper.java.additional.2=-Xms2800m
wrapper.java.additional.3=-Xmx2800m
wrapper.java.additional.4=-XX:PermSize=80m
wrapper.java.additional.5=-XX:MaxPermSize=256m
wrapper.java.additional.6=-XX:NewSize=512m
wrapper.java.additional.7=-XX:MaxNewSize=512m
wrapper.java.additional.8=-Xverbosegc:file=/opt/otm/gc3v55_prod2/logs/tomcat/trace/java.vgc
wrapper.java.additional.9=-Xnoclassgc
wrapper.java.additional.10=-DGC3EncodedPassword=Q0hBTkdFTUU=
wrapper.java.additional.11=-Dglog.properties=glog.tomcat.properties
wrapper.java.additional.12=-Dglog.home=%GLOG_HOME%/glog/config
wrapper.java.additional.13=-Duser.home=%GLOG_HOME%/glog/config
wrapper.java.additional.14=-Djava.io.tmpdir=%GLOG_HOME%/temp
wrapper.java.additional.15=-Djava.awt.headless=true
wrapper.java.additional.16=-Djava.security.auth.login.config=%GLOG_HOME%/glog/config/g
c3_jaas.config
wrapper.java.additional.17=-Dweblogic.ThreadPoolSize=15
wrapper.java.additional.18=-Djava.endorsed.dirs=%GLOG_HOME%/tomcat/common/endorsed
wrapper.java.additional.19=-Dcatalina.base=%GLOG_HOME%/tomcat
wrapper.java.additional.20=-Dcatalina.home=%GLOG_HOME%/tomcat
wrapper.java.additional.21=-XX:+UseParallelGC
wrapper.java.additional.22=-XX:+PrintGCDetails

Do you have bad experience as well using UseParallelGC??