ZGC: A Decade of Redefining Java Performance
summary
ZGC goes from an experimental JDK11 feature to a production collector in JDK25/26, claiming sub‑millisecond pause times by doing liveness analysis, object movement and freeing concurrently; adding generational ZGC in JDK21/25 cuts CPU and allocation stalls and lets it handle terabyte heaps; SPECjbb2015 comparisons show much better P99 latency vs G1 as heap grows, with throughput converging at large heaps; a 32 GB/16‑vCPU automatic heap sizing simulation dynamically adjusts per‑instance heaps and maintains response times.
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chapters (11)
- 0:00Introduction to ZGC
- 1:02Measuring GC performance
- 5:01The foundation of ZGC
- 8:07Early ZGC performance
- 11:07Refining ZGC features
- 13:49Generational ZGC
- 16:19Modern ZGC advancements
- 19:17Performance analysis
- 23:28Benchmarking ZGC vs G1
- 30:38Automatic heap sizing
- 39:01Key takeaways and Q&A
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