> From: laredotornado [mailto:laredotorn...@gmail.com] > Subject: Tuning garbage collection > > I'm using Tomcat 6.0.26, Java 1.6 and wondering what > tools/strategies you use to tune your garbage collection > parameters?
Usually, just give the JVM as big a heap as will fit on your system with inducing paging, and let the GC algorithms figure out what to do with it. Second-guessing the GC usually ends up degrading performance, unless you're willing to do a lot of experimentation using the workloads you actually have. If you really want to play with it (and have a lot of spare time), start here: http://java.sun.com/javase/technologies/hotspot/gc/index.jsp In particular, look at this one: http://java.sun.com/javase/technologies/hotspot/gc/gc_tuning_6.html Optimizing your webapps (and data base) almost always provides greater benefit that fiddling with GC settings. > Further, does anyone know how to read entries in the garbage > collection log? See the above reference. > Desired survivor size 10944512 bytes, new threshold 1 (max 15) That says the survivor space is just under 11 MB, and objects will be moved to the survivor space after just one collection. > [PSYoungGen: 129311K->3232K(136512K)] 558882K->434085K(585920K), The young generation usage was 129 MB before the GC, 3 MB after, and the young gen could use up as much as 136 MB. The total heap usage was 558 MB, shrunk to 434 MB by the GC, and could reach a maximum of 585 MB. > 0.0090900 secs] The minor GC took just over 9 milliseconds. - Chuck THIS COMMUNICATION MAY CONTAIN CONFIDENTIAL AND/OR OTHERWISE PROPRIETARY MATERIAL and is thus for use only by the intended recipient. If you received this in error, please contact the sender and delete the e-mail and its attachments from all computers. --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
