A profiler shows frequent minor (Scavenge) GCs and a high promotion rate into old space, even though the workload conceptually produces short-lived objects. One contributing cause is that the new space (semi-space) is too small relative to the allocation rate. Mechanically, why does an undersized new space inflate the promotion rate?
// many objects that 'should' die young are being tenured
// --max-semi-space-size is at its small default