Hi all, I have a very small Ceph setup - 3 OSDs, 3 MDS, 3 MON, CephFS with ~20 ceph-fuse clients connected. All run version 14.2.9 (both servers and clients). Some clients work with a relatively large CephFS directory, few tens of thousands of files, with lots of files being added and deleted all the time. Almost every day I see exactly the same pattern when system goes under load: - One of the clients starts running slow (e.g. high CPU or out-of-memory, sometimes with OOM killer intervention) - A number of requests from other clients gets blocked for ~15 seconds waiting for the (r/w/x)lock on other files in the same directory - Objecter requests empty - No requests visibly running in the dump_ops_in_flight output, only those waiting for the lock MDS cache size is 1.5 gb, total capacity - around 1TB, usual load is ~300 [rw]ops, 3-4 mb/s, most of the config is the default one. Have somebody seen similar issues before? Best regards, Petr Belyaev