Hi Crystal,
Thank you for your input. For now we don’t observe this memory increase any more, all FSTs seem to have quite settled, after some period.
What has changed since then is that we upgraded the FSTs that were crashing from 4.2.20 to 4.2.28, and we also paused the balancing and group balancing activities.
We observed in total 9 memory kills on 5 FSTs in a 15 days period. The FST were the ones involved in this balancing, so maybe something is linked there. And maybe also this situation led to the strange ghosts files we have in this other issue.