AD sync involving a large number of groups is slow

A Stash customer had it connected to an AD instance with an extremely large amount of groups (in the order of 10s of thousands). The groups have been hidden by a filter, and the resulting synchronization process seems to have been running at a linear pace of (deleting) 100-120 groups/minute. This resulted in the sync lasting days.

Additionally, despite turning on INFO logging on Crowd classes did not result in any progress indication as CWD-3044 would suggest

I recommend investigating with minimum 10000 groups in the AD - whether the progress is similarly slow, or potentially other factors might have affected the customer's instance (e.g. low memory due to large amount of group data?), and whether the process can be optimized for this kind of edge cases (e.g. delete by queries rather than hibernate)