Yes, we moved to G1 (before it was the default) and then on to Shenandoah in a stream processor doing a lot of in-memory processing, lots of small allocations.

Yes, we moved to G1 (before it was the default) and then on to Shenandoah in a stream processor doing a lot of in-memory processing, lots of small allocations. As we reached a certain threshold of in-memory objects, Parallel GC would choke up and we’d see GC pauses which could reach 1s every few seconds, totally unacceptable. No doubt we could have spent time optimising this but moving to G1 brought this down to rarely exceeding 100ms, Shenandoah brought this down further to typically <10ms.