Hi All, Currently we are evaluating G1 in our company, find uncertainty of humongous object is major show stopper issue to roll out G1 in our production. Our heap size is 36G, region size is 16M determined ergonomically by JVM, we find there are about 800~1300 humongous regions during some period which is not acceptable, it was caused by our *ugly* code, after we fix it, we increase region size to 32M (max region size), but we still do see many (>600) short-lived humongous objects during some period. So we have to identify humongous object allocation pattern first.
Based on archived hotspot gc use mail list http://mail.openjdk.java.net/pipermail/hotspot-gc-use/2013-December/date.html#1682 (5 years ago), charlie hunt and Krystal Mok mentioned AllocObjectOutsideTLAB event in JFR, does anyone have some experience in using it to identify humongous objects allocation pattern? BTW, our code base is very big, and we have many server types, goal for me is use some automated ways to find humongous object in our whole code base. And during research, find some promising tool: APROF, BTrace and YourKIT(last resort because it is Commercial). It is highly appreciated that if any of you could provide comment for above tools (JFR, APROF,BTrace, YourKIT) to find humongous objects using automated ways, or pls let me know alternative ways/tools to find humongous objects. BTW, built a custom / modified version of OpenJDK to print humongous objects and stack trace would be a bit impossible for me in short term. Thanks, Roy
_______________________________________________ hotspot-gc-use mailing list hotspot-gc-use@openjdk.java.net http://mail.openjdk.java.net/mailman/listinfo/hotspot-gc-use
