Is JVM ARGS '-Xms1024m -Xmx2048m' still useful in Java 8?

Question

I have a Java 7 application using JVM ARGS: -Xms1024m -Xmx2048m, and it runs pretty well.

After I upgrade to Java 8, it runs in error state with Exception:<

Answer 1

What I know is one reason when “GC overhead limit exceeded” error is thrown when 2% of the memory is freed after several GC cycles

By this error your JVM is signalling that your application is spending too much time in garbage collection. so the little amount GC was able to clean will be quickly filled again thus forcing GC to restart the cleaning process again.

You should try changing the value of -Xmx and -Xms.

Answer 2

Due to PermGen removal some options were removed (like -XX:MaxPermSize), but options -Xms and -Xmx work in Java 8. It's possible that under Java 8 your application simply needs somewhat more memory. Try to increase -Xmx value. Alternatively you can try to switch to G1 garbage collector using -XX:+UseG1GC.

Note that if you use any option which was removed in Java 8, you will see a warning upon application start:

$ java -XX:MaxPermSize=128M -version
Java HotSpot(TM) 64-Bit Server VM warning: ignoring option MaxPermSize=128M; support was removed in 8.0
java version "1.8.0_25"
Java(TM) SE Runtime Environment (build 1.8.0_25-b18)
Java HotSpot(TM) 64-Bit Server VM (build 25.25-b02, mixed mode)