G1, ZGC, and Shenandoah: OpenJDK's Garbage Collectors for Very Large Heaps

Compares three modern OpenJDK garbage collectors—G1, ZGC, and Shenandoah—for managing very large heaps (16GB+). G1 balances throughput and predictable pause times for medium-to-large heaps. ZGC delivers ultra-low latency (sub-millisecond pauses) and scales to 16TB heaps, ideal for latency-critical applications. Shenandoah optimizes for low latency through concurrent compaction, reducing fragmentation. Includes performance comparison across pause times, throughput, and memory footprint, plus best practices for heap sizing by setting -Xms and -Xmx to identical values to eliminate resizing overhead and improve predictability.