Hi @diaconutheodor
There are only 15 documents returned by that query, I checked in mongo and the cursor size is 1043 (I think it should be just a kb). All the 15 documents should weight less than 70k. We’re not trying to fetch a lot of users at the same time.
I’ve seen some issues with collection fetchs too, eg: trying to retrieve a user by email takes around 3 seconds.

You can see there’s a limit and there’s actually an index for “emails.address” in the users collection by default, and there’s actually any user with that e-mail, so it returned 0 results.
Thanks for your reply, will investigate redis-oplog, but our current workload isn’t really that much, I really don’t understand why some operations take too long.