Alfresco Performance tuning by setting JVM memory parameters

Since last couple of days I was working on Alfresco's JVM tuning. I faced below issues when it was configured previously.

• OldGen space was utilized completely
• Per Survivor Space was too utilized completely
• Full GC was taking time which leads to stop application responding for time being

My previous JVM settings were as given below:

export JAVA_OPTS="-Xms2048m -Xmx4096m -Xss1024k -XX:MaxPermSize=512m -XX:NewSize=1024m -XX:+UseConcMarkSweepGC -XX:+UseCodeCacheFlushing -XX:ReservedCodeCacheSize=64m -Djava.awt.headless=true -Dalfresco.home=/opt/alfresco4 -Dcom.sun.management.jmxremote -Dcom.sun.management.jmxremote.ssl=false -Dsun.security.ssl.allowUnsafeRenegotiation=true -Djava.net.preferIPv4Stack=true"

After making changes in few parameters, I got below settings which works perfectly fine. I had to increase memory allocation and tune other parameters.

export JAVA_OPTS="-Xms4096m -Xmx8192m -XX:MaxPermSize=512m -XX:NewSize=3072m -XX:+UseConcMarkSweepGC -XX:+UseCodeCacheFlushing -XX:ReservedCodeCacheSize=64m -Djava.awt.headless=true -Dalfresco.home=/opt/alfresco4 -Dcom.sun.management.jmxremote -Dcom.sun.management.jmxremote.ssl=false -Dsun.security.ssl.allowUnsafeRenegotiation=true -Djava.net.preferIPv4Stack=true"

I have taken screenshot from VisualVM.

Heap Memory and CPU Usage:

OldGen and Eden Space usage: