Re:Clojure and Overtone Driving Minecraft
by needusername on Monday March 02, 2015 @12:03PM
(#9132890)
I though that
-XX:+AggressiveOpts
Re:Clojure and Overtone Driving Minecraft
by xenophonf on Wednesday March 04, 2015 @11:56AM
(#9145577)
It depends on the JVM release. On my Windows 8.1 laptop running 1.8.0_31,this flag increases AutoBoxCacheMax from 128 to 20000 (which affects autoboxing and collections performance), and it lowers BiasedLockingStartupDelay from 20000 to 500 (which can effect multithreaded access to shared data - see http://www.oracle.com/technetwork/java/tuning-139912.html#se... for more details).
It isn't strictly necessary, but if you're trying to squeeze every possible drop of performance out of your Minecraft server, the experimental optimizations aren't a bad thing to enable. I will admit to doing only informal performance testing when it comes to the AggressiveOpts flag.
Re:Clojure and Overtone Driving Minecraft
by josephwilk on Wednesday March 04, 2015 @09:34AM
(#9144404)
Thats really helpful, thanks! Will give it a try.
-d64 (force a 64-bit data model, although usually this isn't necessary)
-server (use the server-optimized JVM instead of the desktop-optimized one, again, may not be necessary)
-Xmx1G (start with this heap memory limit and increase if necessary)
-XX:+UseConcMarkSweepGC (for multithreaded GC)
-XX:+CMSIncrementalMode (only use on computers that support 1 or 2 hardware threads)
-XX:+AggressiveOpts (enables additional JVM optimizations)
There's a ton of bad advice out there when it comes to JVM configuration and Minecraft. The above comes from my understanding of this somewhat dated Java GC tuning guide (http://www.oracle.com/technetwork/java/gc-tuning-6-140523.ht...) and sk89q's excellent Minecraft server tuning guide (http://www.sk89q.com/2013/03/improving-your-minecraft-server...), coupled with small-scale server profiling on my part.