They managed to tune it to an acceptable level in our use case but we’d still see 50ms variation in the long tail responses. I think there are applications for whom that wouldn’t be acceptable. Like I said - it may not be fair but the impression I walked away with is that I don’t want GC in my database.
GC development is not standing still. Oracle claims sub 10ms pause times and terabyte heaps their new ZGC. And there are good pauseless or almost pauseless alternatives from other vendors as well.
The JVM cannot know in advance if you prefer throughput or predictability.