Hi, I run three hobby relays and I seem to be seeing the same behavior on one of them. I compared two similar ARM, 2-core, non-exit Guard+HSDir relays, both running Tor 0.4.9.13. On the affected relay I measured 41,240 BEGIN_DIR streams in 61 seconds (~676/s). The Tor main thread reaches about 100% CPU, ntor onionskins are being dropped, and traffic is strongly asymmetric — roughly 2.2 MB/s read vs 7.1 MB/s written. On my other Guard+HSDir relay, measured at roughly the same time, I saw only 148 BEGIN_DIR streams in 60 seconds (~2.5/s). That relay carries much more traffic (~15 MB/s in both directions) and appears healthy. So in my case, simply having the HSDir flag does not seem sufficient to trigger the issue. One relay is affected, while another Guard+HSDir relay is not. I’m only a hobby relay operator, so I’m posting these numbers mainly in case they are useful for comparison. Regards, KhanKrum