[coredog64]

For a long time, the guidance was to install jemalloc and then use off-heap objects. I can’t recall what it was, but that broke in the 3.0.x series and is unlikely to return. The feature stream (3.1.x) allegedly can use jemalloc again, but we’ve been slow to adopt it so I can’t provide proof.

[ADefenestrator]

The good news is, at least for my workloads, garbage collection is significantly better in 3.0 than 2.1 even without off-heap objects. Not sure if it's generating less or just generating it in a way that's easier to collect cheaply, but I saw pause times and total collection work drop significantly with the same settings (G1 collector)