JDK21/24 ZGC Generational Extra Performance Overhead
5 Aug
2025
5 Aug
'25
1:59 a.m.
Hello ZGC team, Recently we planned to upgrade JDK Our application is a Netty based gateway to route HTTP requests from ALB to upstream application servers. During the performance tests, we observed if using ZGC generational, it will cause extra 10% CPU overhead and the overall capacity was decreased 10% -15% which was a huge degradation. Unfortunately the normal ZGC was disabled in JDK 24. Attached JDK 21 and JDK 24 gc logs under the same workload, we could observe much more concurrent time cost when using ZGC generational. Would you help to advise what's the cause for the extra overhead using ZGC generational and how to optimize, thank you! -- Best Regards! Jack Ling
218
Age (days ago)
218
Last active (days ago)
0 comments
1 participants
participants (1)
-
Jack Ling