java web server jvm common tuning

gistfile1.txt

-Xms              initial java heap size
-Xmx	          maximum java heap size
-Xmn	          the size of the heap for the young generation
-XX:PermSize:     initial value
-XX:MaxPermSize:  max value
 
It is good practice with server-side Java applications to set the minimum -Xms and maximum -Xmx heap sizes to the same value.
For efficient garbage collection, the -Xmn value should be lower than the -Xmx value.

-server
-XX:+UseConcMarkSweepGC
-XX:+ExplicitGCInvokesConcurrent

-XX:+PrintGCDetails
-XX:+HeapDumpOnOutOfMemoryError

http://blog.headius.com/2009/01/my-favorite-hotspot-jvm-flags.html
http://stackoverflow.com/questions/1518213/read-java-jvm-startup-parameters-eg-xmx

The ultimate gc log settings for Java 8:

-Xloggc:logs/gc.log
-XX:+PrintGCDetails
-XX:+PrintTenuringDistribution
-XX:+PrintGCDateStamps
-XX:+PrintGCApplicationStoppedTime
-XX:+PrintGCApplicationConcurrentTime
-XX:+PrintReferenceGC