Comments on: JavaOne: G1 Garbage Collector

By: Paul

Paul — Tue, 09 Mar 2010 18:40:03 +0000

We also experienced a truly massive performance boost with G1 — we run on a 16 core machine with 64->128 GB RAM. Unfortunately, it crashes for us in production when running under high load (on JDK 1.6 _18) so we’ll have to wait and try again on the next build. :(

By: Mark

Mark — Sun, 07 Mar 2010 18:57:37 +0000

Well I can say some good things about G1GC, we have some simulations that usually take an hour to maybe six hours on the long end. Our code is VERY memory intensive, we went to 64bit JVMs just to free up some memory limitations. We turned on G1GC via the -XX option and got a 25% reduction of runtime! This isn’t on JDK7 but on JDK1.6.0.14 on Centos 5.3 64bit. I can’t wait until JDK7 is out and we move to that but for now we’ll be turning on this option.
Mark

By: Ravi Gupta

Ravi Gupta — Fri, 29 Jan 2010 14:37:46 +0000

Sounds very interesting. Would be nice if we can see some benchmarking details also.

By: Saikrishna Vayara

Saikrishna Vayara — Mon, 14 Sep 2009 04:48:39 +0000

Thanks Alex for the heads up information. Useful for analysis of the new JDK and help easier decision making whether to adapt the new version or not.

By: Ole Friis Østergaard

Ole Friis Østergaard — Wed, 01 Apr 2009 15:35:37 +0000

Thanks for the summary – very interesting. However, what’s the difference between the G1 approach and train garbage collection? It sounds very similar: Small “train wagons” that are in turn collected and reused, and “remember sets” that keep track of what other objects point to the current wagon. Train GC had really small individual garbage collection time slots, and thus was great for real-time systems (in principle), but was removed from Java because it simply performed too bad overall, as far as I know.